Konrad Rzeszutek Wilk [Thu, 17 May 2018 03:18:09 +0000 (23:18 -0400)]
x86/bugs: Rename SSBD_NO to SSB_NO
commit
240da953fcc6a9008c92fae5b1f727ee5ed167ab upstream.
The "336996 Speculative Execution Side Channel Mitigations" from
May defines this as SSB_NO, hence lets sync-up.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Tom Lendacky [Thu, 10 May 2018 20:06:39 +0000 (22:06 +0200)]
KVM: SVM: Implement VIRT_SPEC_CTRL support for SSBD
commit
bc226f07dcd3c9ef0b7f6236fe356ea4a9cb4769 upstream.
Expose the new virtualized architectural mechanism, VIRT_SSBD, for using
speculative store bypass disable (SSBD) under SVM. This will allow guests
to use SSBD on hardware that uses non-architectural mechanisms for enabling
SSBD.
[ tglx: Folded the migration fixup from Paolo Bonzini ]
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.16:
- There is no SMM support or cpu_has_high_real_mode_segbase operation
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Thomas Gleixner [Thu, 10 May 2018 18:42:48 +0000 (20:42 +0200)]
x86/speculation, KVM: Implement support for VIRT_SPEC_CTRL/LS_CFG
commit
47c61b3955cf712cadfc25635bf9bc174af030ea upstream.
Add the necessary logic for supporting the emulated VIRT_SPEC_CTRL MSR to
x86_virt_spec_ctrl(). If either X86_FEATURE_LS_CFG_SSBD or
X86_FEATURE_VIRT_SPEC_CTRL is set then use the new guest_virt_spec_ctrl
argument to check whether the state must be modified on the host. The
update reuses speculative_store_bypass_update() so the ZEN-specific sibling
coordination can be reused.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Thomas Gleixner [Sat, 12 May 2018 18:10:00 +0000 (20:10 +0200)]
x86/bugs: Rework spec_ctrl base and mask logic
commit
be6fcb5478e95bb1c91f489121238deb3abca46a upstream.
x86_spec_ctrL_mask is intended to mask out bits from a MSR_SPEC_CTRL value
which are not to be modified. However the implementation is not really used
and the bitmask was inverted to make a check easier, which was removed in
"x86/bugs: Remove x86_spec_ctrl_set()"
Aside of that it is missing the STIBP bit if it is supported by the
platform, so if the mask would be used in x86_virt_spec_ctrl() then it
would prevent a guest from setting STIBP.
Add the STIBP bit if supported and use the mask in x86_virt_spec_ctrl() to
sanitize the value which is supplied by the guest.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Thomas Gleixner [Sat, 12 May 2018 18:53:14 +0000 (20:53 +0200)]
x86/bugs: Remove x86_spec_ctrl_set()
commit
4b59bdb569453a60b752b274ca61f009e37f4dae upstream.
x86_spec_ctrl_set() is only used in bugs.c and the extra mask checks there
provide no real value as both call sites can just write x86_spec_ctrl_base
to MSR_SPEC_CTRL. x86_spec_ctrl_base is valid and does not need any extra
masking or checking.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Thomas Gleixner [Sat, 12 May 2018 18:49:16 +0000 (20:49 +0200)]
x86/bugs: Expose x86_spec_ctrl_base directly
commit
fa8ac4988249c38476f6ad678a4848a736373403 upstream.
x86_spec_ctrl_base is the system wide default value for the SPEC_CTRL MSR.
x86_spec_ctrl_get_default() returns x86_spec_ctrl_base and was intended to
prevent modification to that variable. Though the variable is read only
after init and globaly visible already.
Remove the function and export the variable instead.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Borislav Petkov [Fri, 11 May 2018 22:14:51 +0000 (00:14 +0200)]
x86/bugs: Unify x86_spec_ctrl_{set_guest,restore_host}
commit
cc69b34989210f067b2c51d5539b5f96ebcc3a01 upstream.
Function bodies are very similar and are going to grow more almost
identical code. Add a bool arg to determine whether SPEC_CTRL is being set
for the guest or restored to the host.
No functional changes.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Thomas Gleixner [Thu, 10 May 2018 18:31:44 +0000 (20:31 +0200)]
x86/speculation: Rework speculative_store_bypass_update()
commit
0270be3e34efb05a88bc4c422572ece038ef3608 upstream.
The upcoming support for the virtual SPEC_CTRL MSR on AMD needs to reuse
speculative_store_bypass_update() to avoid code duplication. Add an
argument for supplying a thread info (TIF) value and create a wrapper
speculative_store_bypass_update_current() which is used at the existing
call site.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Tom Lendacky [Thu, 17 May 2018 15:09:18 +0000 (17:09 +0200)]
x86/speculation: Add virtualized speculative store bypass disable support
commit
11fb0683493b2da112cd64c9dada221b52463bf7 upstream.
Some AMD processors only support a non-architectural means of enabling
speculative store bypass disable (SSBD). To allow a simplified view of
this to a guest, an architectural definition has been created through a new
CPUID bit, 0x80000008_EBX[25], and a new MSR, 0xc001011f. With this, a
hypervisor can virtualize the existence of this definition and provide an
architectural method for using SSBD to a guest.
Add the new CPUID feature, the new MSR and update the existing SSBD
support to use this MSR when present.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.16:
- This CPUID word is feature word 11
- Adjust filenames, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Thomas Gleixner [Wed, 9 May 2018 21:01:01 +0000 (23:01 +0200)]
x86/bugs, KVM: Extend speculation control for VIRT_SPEC_CTRL
commit
ccbcd2674472a978b48c91c1fbfb66c0ff959f24 upstream.
AMD is proposing a VIRT_SPEC_CTRL MSR to handle the Speculative Store
Bypass Disable via MSR_AMD64_LS_CFG so that guests do not have to care
about the bit position of the SSBD bit and thus facilitate migration.
Also, the sibling coordination on Family 17H CPUs can only be done on
the host.
Extend x86_spec_ctrl_set_guest() and x86_spec_ctrl_restore_host() with an
extra argument for the VIRT_SPEC_CTRL MSR.
Hand in 0 from VMX and in SVM add a new virt_spec_ctrl member to the CPU
data structure which is going to be used in later patches for the actual
implementation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Thomas Gleixner [Wed, 9 May 2018 19:53:09 +0000 (21:53 +0200)]
x86/speculation: Handle HT correctly on AMD
commit
1f50ddb4f4189243c05926b842dc1a0332195f31 upstream.
The AMD64_LS_CFG MSR is a per core MSR on Family 17H CPUs. That means when
hyperthreading is enabled the SSBD bit toggle needs to take both cores into
account. Otherwise the following situation can happen:
CPU0 CPU1
disable SSB
disable SSB
enable SSB <- Enables it for the Core, i.e. for CPU0 as well
So after the SSB enable on CPU1 the task on CPU0 runs with SSB enabled
again.
On Intel the SSBD control is per core as well, but the synchronization
logic is implemented behind the per thread SPEC_CTRL MSR. It works like
this:
CORE_SPEC_CTRL = THREAD0_SPEC_CTRL | THREAD1_SPEC_CTRL
i.e. if one of the threads enables a mitigation then this affects both and
the mitigation is only disabled in the core when both threads disabled it.
Add the necessary synchronization logic for AMD family 17H. Unfortunately
that requires a spinlock to serialize the access to the MSR, but the locks
are only shared between siblings.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.16:
- s/topology_sibling_cpumask/topology_thread_cpumask/
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Thomas Gleixner [Thu, 10 May 2018 14:26:00 +0000 (16:26 +0200)]
x86/cpufeatures: Add FEATURE_ZEN
commit
d1035d971829dcf80e8686ccde26f94b0a069472 upstream.
Add a ZEN feature bit so family-dependent static_cpu_has() optimizations
can be built for ZEN.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.16:
- Use the next available bit number in CPU feature word 7
- Adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Thomas Gleixner [Thu, 10 May 2018 18:21:36 +0000 (20:21 +0200)]
x86/cpufeatures: Disentangle SSBD enumeration
commit
52817587e706686fcdb27f14c1b000c92f266c96 upstream.
The SSBD enumeration is similarly to the other bits magically shared
between Intel and AMD though the mechanisms are different.
Make X86_FEATURE_SSBD synthetic and set it depending on the vendor specific
features or family dependent setup.
Change the Intel bit to X86_FEATURE_SPEC_CTRL_SSBD to denote that SSBD is
controlled via MSR_SPEC_CTRL and fix up the usage sites.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.16:
- Use the next available bit number in CPU feature word 7
- Adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Thomas Gleixner [Thu, 10 May 2018 17:13:18 +0000 (19:13 +0200)]
x86/cpufeatures: Disentangle MSR_SPEC_CTRL enumeration from IBRS
commit
7eb8956a7fec3c1f0abc2a5517dada99ccc8a961 upstream.
The availability of the SPEC_CTRL MSR is enumerated by a CPUID bit on
Intel and implied by IBRS or STIBP support on AMD. That's just confusing
and in case an AMD CPU has IBRS not supported because the underlying
problem has been fixed but has another bit valid in the SPEC_CTRL MSR,
the thing falls apart.
Add a synthetic feature bit X86_FEATURE_MSR_SPEC_CTRL to denote the
availability on both Intel and AMD.
While at it replace the boot_cpu_has() checks with static_cpu_has() where
possible. This prevents late microcode loading from exposing SPEC_CTRL, but
late loading is already very limited as it does not reevaluate the
mitigation options and other bits and pieces. Having static_cpu_has() is
the simplest and least fragile solution.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.16:
- Use the next available bit number in CPU feature word 7
- Adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Borislav Petkov [Wed, 2 May 2018 16:15:14 +0000 (18:15 +0200)]
x86/speculation: Use synthetic bits for IBRS/IBPB/STIBP
commit
e7c587da125291db39ddf1f49b18e5970adbac17 upstream.
Intel and AMD have different CPUID bits hence for those use synthetic bits
which get set on the respective vendor's in init_speculation_control(). So
that debacles like what the commit message of
c65732e4f721 ("x86/cpu: Restore CPUID_8000_0008_EBX reload")
talks about don't happen anymore.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Jörg Otte <jrg.otte@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Link: https://lkml.kernel.org/r/20180504161815.GG9257@pd.tnic
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.16:
- Use the next available bit numbers in CPU feature word 7
- Adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Thomas Gleixner [Fri, 11 May 2018 13:21:01 +0000 (15:21 +0200)]
KVM: SVM: Move spec control call after restore of GS
commit
15e6c22fd8e5a42c5ed6d487b7c9fe44c2517765 upstream.
svm_vcpu_run() invokes x86_spec_ctrl_restore_host() after VMEXIT, but
before the host GS is restored. x86_spec_ctrl_restore_host() uses 'current'
to determine the host SSBD state of the thread. 'current' is GS based, but
host GS is not yet restored and the access causes a triple fault.
Move the call after the host GS restore.
Fixes: 885f82bfbc6f x86/process: Allow runtime control of Speculative Store Bypass
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Jim Mattson [Sun, 13 May 2018 21:33:57 +0000 (17:33 -0400)]
x86/cpu: Make alternative_msr_write work for 32-bit code
commit
5f2b745f5e1304f438f9b2cd03ebc8120b6e0d3b upstream.
Cast val and (val >> 32) to (u32), so that they fit in a
general-purpose register in both 32-bit and 64-bit code.
[ tglx: Made it u32 instead of uintptr_t ]
Fixes: c65732e4f721 ("x86/cpu: Restore CPUID_8000_0008_EBX reload")
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Konrad Rzeszutek Wilk [Fri, 11 May 2018 20:50:35 +0000 (16:50 -0400)]
x86/bugs: Fix the parameters alignment and missing void
commit
ffed645e3be0e32f8e9ab068d257aee8d0fe8eec upstream.
Fixes: 7bb4d366c ("x86/bugs: Make cpu_show_common() static")
Fixes: 24f7fc83b ("x86/bugs: Provide boot parameters for the spec_store_bypass_disable mitigation")
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Jiri Kosina [Thu, 10 May 2018 20:47:32 +0000 (22:47 +0200)]
x86/bugs: Make cpu_show_common() static
commit
7bb4d366cba992904bffa4820d24e70a3de93e76 upstream.
cpu_show_common() is not used outside of arch/x86/kernel/cpu/bugs.c, so
make it static.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Jiri Kosina [Thu, 10 May 2018 20:47:18 +0000 (22:47 +0200)]
x86/bugs: Fix __ssb_select_mitigation() return type
commit
d66d8ff3d21667b41eddbe86b35ab411e40d8c5f upstream.
__ssb_select_mitigation() returns one of the members of enum ssb_mitigation,
not ssb_mitigation_cmd; fix the prototype to reflect that.
Fixes: 24f7fc83b9204 ("x86/bugs: Provide boot parameters for the spec_store_bypass_disable mitigation")
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Borislav Petkov [Tue, 8 May 2018 13:43:45 +0000 (15:43 +0200)]
Documentation/spec_ctrl: Do some minor cleanups
commit
dd0792699c4058e63c0715d9a7c2d40226fcdddc upstream.
Fix some typos, improve formulations, end sentences with a fullstop.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Konrad Rzeszutek Wilk [Wed, 9 May 2018 19:41:38 +0000 (21:41 +0200)]
proc: Use underscores for SSBD in 'status'
commit
e96f46ee8587607a828f783daa6eb5b44d25004d upstream.
The style for the 'status' file is CamelCase or this. _.
Fixes: fae1fa0fc ("proc: Provide details on speculation flaw mitigations")
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Konrad Rzeszutek Wilk [Wed, 9 May 2018 19:41:38 +0000 (21:41 +0200)]
x86/bugs: Rename _RDS to _SSBD
commit
9f65fb29374ee37856dbad847b4e121aab72b510 upstream.
Intel collateral will reference the SSB mitigation bit in IA32_SPEC_CTL[2]
as SSBD (Speculative Store Bypass Disable).
Hence changing it.
It is unclear yet what the MSR_IA32_ARCH_CAPABILITIES (0x10a) Bit(4) name
is going to be. Following the rename it would be SSBD_NO but that rolls out
to Speculative Store Bypass Disable No.
Also fixed the missing space in X86_FEATURE_AMD_SSBD.
[ tglx: Fixup x86_amd_rds_enable() and rds_tif_to_amd_ls_cfg() as well ]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 3.16:
- Update guest_cpuid_has_spec_ctrl() rather than vmx_{get,set}_msr()
- Update _TIF_WORK_MASK and _TIF_ALLWORK_MASK
- Adjust filenames, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Kees Cook [Thu, 3 May 2018 21:37:54 +0000 (14:37 -0700)]
x86/speculation: Make "seccomp" the default mode for Speculative Store Bypass
commit
f21b53b20c754021935ea43364dbf53778eeba32 upstream.
Unless explicitly opted out of, anything running under seccomp will have
SSB mitigations enabled. Choosing the "prctl" mode will disable this.
[ tglx: Adjusted it to the new arch_seccomp_spec_mitigate() mechanism ]
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Thomas Gleixner [Fri, 4 May 2018 13:12:06 +0000 (15:12 +0200)]
seccomp: Move speculation migitation control to arch code
commit
8bf37d8c067bb7eb8e7c381bdadf9bd89182b6bc upstream.
The migitation control is simpler to implement in architecture code as it
avoids the extra function call to check the mode. Aside of that having an
explicit seccomp enabled mode in the architecture mitigations would require
even more workarounds.
Move it into architecture code and provide a weak function in the seccomp
code. Remove the 'which' argument as this allows the architecture to decide
which mitigations are relevant for seccomp.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Kees Cook [Thu, 3 May 2018 21:56:12 +0000 (14:56 -0700)]
seccomp: Add filter flag to opt-out of SSB mitigation
commit
00a02d0c502a06d15e07b857f8ff921e3e402675 upstream.
If a seccomp user is not interested in Speculative Store Bypass mitigation
by default, it can set the new SECCOMP_FILTER_FLAG_SPEC_ALLOW flag when
adding filters.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 3.16:
- We don't support SECCOMP_FILTER_FLAG_TSYNC or SECCOMP_FILTER_FLAG_LOG
- Drop selftest changes]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Thomas Gleixner [Fri, 4 May 2018 07:40:03 +0000 (09:40 +0200)]
seccomp: Use PR_SPEC_FORCE_DISABLE
commit
b849a812f7eb92e96d1c8239b06581b2cfd8b275 upstream.
Use PR_SPEC_FORCE_DISABLE in seccomp() because seccomp does not allow to
widen restrictions.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Thomas Gleixner [Thu, 3 May 2018 20:09:15 +0000 (22:09 +0200)]
prctl: Add force disable speculation
commit
356e4bfff2c5489e016fdb925adbf12a1e3950ee upstream.
For certain use cases it is desired to enforce mitigations so they cannot
be undone afterwards. That's important for loader stubs which want to
prevent a child from disabling the mitigation again. Will also be used for
seccomp(). The extra state preserving of the prctl state for SSB is a
preparatory step for EBPF dymanic speculation control.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 3.16: adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Kees Cook [Tue, 1 May 2018 22:07:31 +0000 (15:07 -0700)]
seccomp: Enable speculation flaw mitigations
commit
5c3070890d06ff82eecb808d02d2ca39169533ef upstream.
When speculation flaw mitigations are opt-in (via prctl), using seccomp
will automatically opt-in to these protections, since using seccomp
indicates at least some level of sandboxing is desired.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 3.16:
- Apply to current task
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Kees Cook [Tue, 1 May 2018 22:31:45 +0000 (15:31 -0700)]
proc: Provide details on speculation flaw mitigations
commit
fae1fa0fc6cca8beee3ab8ed71d54f9a78fa3f64 upstream.
As done with seccomp and no_new_privs, also show speculation flaw
mitigation state in /proc/$pid/status.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Kees Cook [Tue, 1 May 2018 22:19:04 +0000 (15:19 -0700)]
nospec: Allow getting/setting on non-current task
commit
7bbf1373e228840bb0295a2ca26d548ef37f448e upstream.
Adjust arch_prctl_get/set_spec_ctrl() to operate on tasks other than
current.
This is needed both for /proc/$pid/status queries and for seccomp (since
thread-syncing can trigger seccomp in non-current threads).
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Thomas Gleixner [Sun, 29 Apr 2018 13:26:40 +0000 (15:26 +0200)]
x86/speculation: Add prctl for Speculative Store Bypass mitigation
commit
a73ec77ee17ec556fe7f165d00314cb7c047b1ac upstream.
Add prctl based control for Speculative Store Bypass mitigation and make it
the default mitigation for Intel and AMD.
Andi Kleen provided the following rationale (slightly redacted):
There are multiple levels of impact of Speculative Store Bypass:
1) JITed sandbox.
It cannot invoke system calls, but can do PRIME+PROBE and may have call
interfaces to other code
2) Native code process.
No protection inside the process at this level.
3) Kernel.
4) Between processes.
The prctl tries to protect against case (1) doing attacks.
If the untrusted code can do random system calls then control is already
lost in a much worse way. So there needs to be system call protection in
some way (using a JIT not allowing them or seccomp). Or rather if the
process can subvert its environment somehow to do the prctl it can already
execute arbitrary code, which is much worse than SSB.
To put it differently, the point of the prctl is to not allow JITed code
to read data it shouldn't read from its JITed sandbox. If it already has
escaped its sandbox then it can already read everything it wants in its
address space, and do much worse.
The ability to control Speculative Store Bypass allows to enable the
protection selectively without affecting overall system performance.
Based on an initial patch from Tim Chen. Completely rewritten.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Thomas Gleixner [Sun, 29 Apr 2018 13:21:42 +0000 (15:21 +0200)]
x86/process: Allow runtime control of Speculative Store Bypass
commit
885f82bfbc6fefb6664ea27965c3ab9ac4194b8c upstream.
The Speculative Store Bypass vulnerability can be mitigated with the
Reduced Data Speculation (RDS) feature. To allow finer grained control of
this eventually expensive mitigation a per task mitigation control is
required.
Add a new TIF_RDS flag and put it into the group of TIF flags which are
evaluated for mismatch in switch_to(). If these bits differ in the previous
and the next task, then the slow path function __switch_to_xtra() is
invoked. Implement the TIF_RDS dependent mitigation control in the slow
path.
If the prctl for controlling Speculative Store Bypass is disabled or no
task uses the prctl then there is no overhead in the switch_to() fast
path.
Update the KVM related speculation control functions to take TID_RDS into
account as well.
Based on a patch from Tim Chen. Completely rewritten.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[bwh: Backported to 3.16:
- Exclude _TIF_RDS from _TIF_WORK_MASK and _TIF_ALLWORK_MASK
- Adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Thomas Gleixner [Sun, 29 Apr 2018 13:20:11 +0000 (15:20 +0200)]
prctl: Add speculation control prctls
commit
b617cfc858161140d69cc0b5cc211996b557a1c7 upstream.
Add two new prctls to control aspects of speculation related vulnerabilites
and their mitigations to provide finer grained control over performance
impacting mitigations.
PR_GET_SPECULATION_CTRL returns the state of the speculation misfeature
which is selected with arg2 of prctl(2). The return value uses bit 0-2 with
the following meaning:
Bit Define Description
0 PR_SPEC_PRCTL Mitigation can be controlled per task by
PR_SET_SPECULATION_CTRL
1 PR_SPEC_ENABLE The speculation feature is enabled, mitigation is
disabled
2 PR_SPEC_DISABLE The speculation feature is disabled, mitigation is
enabled
If all bits are 0 the CPU is not affected by the speculation misfeature.
If PR_SPEC_PRCTL is set, then the per task control of the mitigation is
available. If not set, prctl(PR_SET_SPECULATION_CTRL) for the speculation
misfeature will fail.
PR_SET_SPECULATION_CTRL allows to control the speculation misfeature, which
is selected by arg2 of prctl(2) per task. arg3 is used to hand in the
control value, i.e. either PR_SPEC_ENABLE or PR_SPEC_DISABLE.
The common return values are:
EINVAL prctl is not implemented by the architecture or the unused prctl()
arguments are not 0
ENODEV arg2 is selecting a not supported speculation misfeature
PR_SET_SPECULATION_CTRL has these additional return values:
ERANGE arg3 is incorrect, i.e. it's not either PR_SPEC_ENABLE or PR_SPEC_DISABLE
ENXIO prctl control of the selected speculation misfeature is disabled
The first supported controlable speculation misfeature is
PR_SPEC_STORE_BYPASS. Add the define so this can be shared between
architectures.
Based on an initial patch from Tim Chen and mostly rewritten.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[bwh: Backported to 3.16:
- Add the documentation directly under Documentation/ since there is
no userspace-api subdirectory or reST index
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Thomas Gleixner [Sun, 29 Apr 2018 13:01:37 +0000 (15:01 +0200)]
x86/speculation: Create spec-ctrl.h to avoid include hell
commit
28a2775217b17208811fa43a9e96bd1fdf417b86 upstream.
Having everything in nospec-branch.h creates a hell of dependencies when
adding the prctl based switching mechanism. Move everything which is not
required in nospec-branch.h to spec-ctrl.h and fix up the includes in the
relevant files.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Konrad Rzeszutek Wilk [Thu, 26 Apr 2018 02:04:25 +0000 (22:04 -0400)]
x86/KVM/VMX: Expose SPEC_CTRL Bit(2) to the guest
commit
da39556f66f5cfe8f9c989206974f1cb16ca5d7c upstream.
Expose the CPUID.7.EDX[31] bit to the guest, and also guard against various
combinations of SPEC_CTRL MSR values.
The handling of the MSR (to take into account the host value of SPEC_CTRL
Bit(2)) is taken care of in patch:
KVM/SVM/VMX/x86/spectre_v2: Support the combination of guest and host IBRS
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
[dwmw2: Handle 4.9 guest CPUID differences, rename
guest_cpu_has_ibrs() → guest_cpu_has_spec_ctrl()]
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Konrad Rzeszutek Wilk [Thu, 26 Apr 2018 02:04:24 +0000 (22:04 -0400)]
x86/bugs/AMD: Add support to disable RDS on Fam[15,16,17]h if requested
commit
764f3c21588a059cd783c6ba0734d4db2d72822d upstream.
AMD does not need the Speculative Store Bypass mitigation to be enabled.
The parameters for this are already available and can be done via MSR
C001_1020. Each family uses a different bit in that MSR for this.
[ tglx: Expose the bit mask via a variable and move the actual MSR fiddling
into the bugs code as that's the right thing to do and also required
to prepare for dynamic enable/disable ]
Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.16:
- Renumber the feature bit
- We don't have __ro_after_init
- Adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Konrad Rzeszutek Wilk [Thu, 26 Apr 2018 02:04:23 +0000 (22:04 -0400)]
x86/bugs: Whitelist allowed SPEC_CTRL MSR values
commit
1115a859f33276fe8afb31c60cf9d8e657872558 upstream.
Intel and AMD SPEC_CTRL (0x48) MSR semantics may differ in the
future (or in fact use different MSRs for the same functionality).
As such a run-time mechanism is required to whitelist the appropriate MSR
values.
[ tglx: Made the variable __ro_after_init ]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.16:
- We don't have __ro_after_init
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Konrad Rzeszutek Wilk [Thu, 26 Apr 2018 02:04:22 +0000 (22:04 -0400)]
x86/bugs/intel: Set proper CPU features and setup RDS
commit
772439717dbf703b39990be58d8d4e3e4ad0598a upstream.
Intel CPUs expose methods to:
- Detect whether RDS capability is available via CPUID.7.0.EDX[31],
- The SPEC_CTRL MSR(0x48), bit 2 set to enable RDS.
- MSR_IA32_ARCH_CAPABILITIES, Bit(4) no need to enable RRS.
With that in mind if spec_store_bypass_disable=[auto,on] is selected set at
boot-time the SPEC_CTRL MSR to enable RDS if the platform requires it.
Note that this does not fix the KVM case where the SPEC_CTRL is exposed to
guests which can muck with it, see patch titled :
KVM/SVM/VMX/x86/spectre_v2: Support the combination of guest and host IBRS.
And for the firmware (IBRS to be set), see patch titled:
x86/spectre_v2: Read SPEC_CTRL MSR during boot and re-use reserved bits
[ tglx: Distangled it from the intel implementation and kept the call order ]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.16: adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Konrad Rzeszutek Wilk [Thu, 26 Apr 2018 02:04:21 +0000 (22:04 -0400)]
x86/bugs: Provide boot parameters for the spec_store_bypass_disable mitigation
commit
24f7fc83b9204d20f878c57cb77d261ae825e033 upstream.
Contemporary high performance processors use a common industry-wide
optimization known as "Speculative Store Bypass" in which loads from
addresses to which a recent store has occurred may (speculatively) see an
older value. Intel refers to this feature as "Memory Disambiguation" which
is part of their "Smart Memory Access" capability.
Memory Disambiguation can expose a cache side-channel attack against such
speculatively read values. An attacker can create exploit code that allows
them to read memory outside of a sandbox environment (for example,
malicious JavaScript in a web page), or to perform more complex attacks
against code running within the same privilege level, e.g. via the stack.
As a first step to mitigate against such attacks, provide two boot command
line control knobs:
nospec_store_bypass_disable
spec_store_bypass_disable=[off,auto,on]
By default affected x86 processors will power on with Speculative
Store Bypass enabled. Hence the provided kernel parameters are written
from the point of view of whether to enable a mitigation or not.
The parameters are as follows:
- auto - Kernel detects whether your CPU model contains an implementation
of Speculative Store Bypass and picks the most appropriate
mitigation.
- on - disable Speculative Store Bypass
- off - enable Speculative Store Bypass
[ tglx: Reordered the checks so that the whole evaluation is not done
when the CPU does not support RDS ]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.16:
- Renumber the feature bit
- Adjust filenames, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Konrad Rzeszutek Wilk [Sat, 28 Apr 2018 20:34:17 +0000 (22:34 +0200)]
x86/cpufeatures: Add X86_FEATURE_RDS
commit
0cc5fa00b0a88dad140b4e5c2cead9951ad36822 upstream.
Add the CPU feature bit CPUID.7.0.EDX[31] which indicates whether the CPU
supports Reduced Data Speculation.
[ tglx: Split it out from a later patch ]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.16:
- This CPUID word is feature word 10
- Adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Konrad Rzeszutek Wilk [Thu, 26 Apr 2018 02:04:20 +0000 (22:04 -0400)]
x86/bugs: Expose /sys/../spec_store_bypass
commit
c456442cd3a59eeb1d60293c26cbe2ff2c4e42cf upstream.
Add the sysfs file for the new vulerability. It does not do much except
show the words 'Vulnerable' for recent x86 cores.
Intel cores prior to family 6 are known not to be vulnerable, and so are
some Atoms and some Xeon Phi.
It assumes that older Cyrix, Centaur, etc. cores are immune.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.16:
- Renumber X86_BUG_SPEC_STORE_BYPASS
- Adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Konrad Rzeszutek Wilk [Thu, 26 Apr 2018 02:04:19 +0000 (22:04 -0400)]
x86/bugs, KVM: Support the combination of guest and host IBRS
commit
5cf687548705412da47c9cec342fd952d71ed3d5 upstream.
A guest may modify the SPEC_CTRL MSR from the value used by the
kernel. Since the kernel doesn't use IBRS, this means a value of zero is
what is needed in the host.
But the 336996-Speculative-Execution-Side-Channel-Mitigations.pdf refers to
the other bits as reserved so the kernel should respect the boot time
SPEC_CTRL value and use that.
This allows to deal with future extensions to the SPEC_CTRL interface if
any at all.
Note: This uses wrmsrl() instead of native_wrmsl(). I does not make any
difference as paravirt will over-write the callq *0xfff.. with the wrmsrl
assembler code.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Konrad Rzeszutek Wilk [Thu, 26 Apr 2018 02:04:18 +0000 (22:04 -0400)]
x86/bugs: Read SPEC_CTRL MSR during boot and re-use reserved bits
commit
1b86883ccb8d5d9506529d42dbe1a5257cb30b18 upstream.
The 336996-Speculative-Execution-Side-Channel-Mitigations.pdf refers to all
the other bits as reserved. The Intel SDM glossary defines reserved as
implementation specific - aka unknown.
As such at bootup this must be taken it into account and proper masking for
the bits in use applied.
A copy of this document is available at
https://bugzilla.kernel.org/show_bug.cgi?id=199511
[ tglx: Made x86_spec_ctrl_base __ro_after_init ]
Suggested-by: Jon Masters <jcm@redhat.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.16:
- We don't have __ro_after_init
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Konrad Rzeszutek Wilk [Thu, 26 Apr 2018 02:04:17 +0000 (22:04 -0400)]
x86/bugs: Concentrate bug reporting into a separate function
commit
d1059518b4789cabe34bb4b714d07e6089c82ca1 upstream.
Those SysFS functions have a similar preamble, as such make common
code to handle them.
Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.16: s/X86_FEATURE_PTI/X86_FEATURE_KAISER/]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Konrad Rzeszutek Wilk [Thu, 26 Apr 2018 02:04:16 +0000 (22:04 -0400)]
x86/bugs: Concentrate bug detection into a separate function
commit
4a28bfe3267b68e22c663ac26185aa16c9b879ef upstream.
Combine the various logic which goes through all those
x86_cpu_id matching structures in one function.
Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Linus Torvalds [Tue, 1 May 2018 13:55:51 +0000 (15:55 +0200)]
x86/nospec: Simplify alternative_msr_write()
commit
1aa7a5735a41418d8e01fa7c9565eb2657e2ea3f upstream.
The macro is not type safe and I did look for why that "g" constraint for
the asm doesn't work: it's because the asm is more fundamentally wrong.
It does
movl %[val], %%eax
but "val" isn't a 32-bit value, so then gcc will pass it in a register,
and generate code like
movl %rsi, %eax
and gas will complain about a nonsensical 'mov' instruction (it's moving a
64-bit register to a 32-bit one).
Passing it through memory will just hide the real bug - gcc still thinks
the memory location is 64-bit, but the "movl" will only load the first 32
bits and it all happens to work because x86 is little-endian.
Convert it to a type safe inline function with a little trick which hands
the feature into the ALTERNATIVE macro.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Ben Hutchings [Tue, 25 Sep 2018 22:47:37 +0000 (23:47 +0100)]
Linux 3.16.58
Linus Torvalds [Thu, 13 Sep 2018 09:57:48 +0000 (23:57 -1000)]
mm: get rid of vmacache_flush_all() entirely
commit
7a9cdebdcc17e426fb5287e4a82db1dfe86339b2 upstream.
Jann Horn points out that the vmacache_flush_all() function is not only
potentially expensive, it's buggy too. It also happens to be entirely
unnecessary, because the sequence number overflow case can be avoided by
simply making the sequence number be 64-bit. That doesn't even grow the
data structures in question, because the other adjacent fields are
already 64-bit.
So simplify the whole thing by just making the sequence number overflow
case go away entirely, which gets rid of all the complications and makes
the code faster too. Win-win.
[ Oleg Nesterov points out that the VMACACHE_FULL_FLUSHES statistics
also just goes away entirely with this ]
Reported-by: Jann Horn <jannh@google.com>
Suggested-by: Will Deacon <will.deacon@arm.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.16: drop changes to mm debug code]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Paolo Bonzini [Tue, 5 May 2015 10:08:55 +0000 (12:08 +0200)]
KVM: x86: introduce num_emulated_msrs
commit
62ef68bb4d00f1a662e487f3fc44ce8521c416aa upstream.
We will want to filter away MSR_IA32_SMBASE from the emulated_msrs if
the host CPU does not support SMM virtualization. Introduce the
logic to do that, and also move paravirt MSRs to emulated_msrs for
simplicity and to get rid of KVM_SAVE_MSRS_BEGIN.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Piotr Luc [Wed, 12 Oct 2016 18:05:20 +0000 (20:05 +0200)]
x86/cpu/intel: Add Knights Mill to Intel family
commit
0047f59834e5947d45f34f5f12eb330d158f700b upstream.
Add CPUID of Knights Mill (KNM) processor to Intel family list.
Signed-off-by: Piotr Luc <piotr.luc@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161012180520.30976-1-piotr.luc@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Borislav Petkov [Thu, 7 Sep 2017 17:08:21 +0000 (19:08 +0200)]
x86/cpu/AMD: Fix erratum 1076 (CPB bit)
commit
f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 upstream.
CPUID Fn8000_0007_EDX[CPB] is wrongly 0 on models up to B1. But they do
support CPB (AMD's Core Performance Boosting cpufreq CPU feature), so fix that.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sherry Hurwitz <sherry.hurwitz@amd.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170907170821.16021-1-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.16:
- Change the added case into an if-statement
- s/x86_stepping/x86_mask/]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Kyle Huey [Tue, 14 Feb 2017 08:11:03 +0000 (00:11 -0800)]
x86/process: Correct and optimize TIF_BLOCKSTEP switch
commit
b9894a2f5bd18b1691cb6872c9afe32b148d0132 upstream.
The debug control MSR is "highly magical" as the blockstep bit can be
cleared by hardware under not well documented circumstances.
So a task switch relying on the bit set by the previous task (according to
the previous tasks thread flags) can trip over this and not update the flag
for the next task.
To fix this its required to handle DEBUGCTLMSR_BTF when either the previous
or the next or both tasks have the TIF_BLOCKSTEP flag set.
While at it avoid branching within the TIF_BLOCKSTEP case and evaluating
boot_cpu_data twice in kernels without CONFIG_X86_DEBUGCTLMSR.
x86_64: arch/x86/kernel/process.o
text data bss dec hex
3024 8577 16 11617 2d61 Before
3008 8577 16 11601 2d51 After
i386: No change
[ tglx: Made the shift value explicit, use a local variable to make the
code readable and massaged changelog]
Originally-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Kyle Huey <khuey@kylehuey.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Link: http://lkml.kernel.org/r/20170214081104.9244-3-khuey@kylehuey.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Kyle Huey [Tue, 14 Feb 2017 08:11:02 +0000 (00:11 -0800)]
x86/process: Optimize TIF checks in __switch_to_xtra()
commit
af8b3cd3934ec60f4c2a420d19a9d416554f140b upstream.
Help the compiler to avoid reevaluating the thread flags for each checked
bit by reordering the bit checks and providing an explicit xor for
evaluation.
With default defconfigs for each arch,
x86_64: arch/x86/kernel/process.o
text data bss dec hex
3056 8577 16 11649 2d81 Before
3024 8577 16 11617 2d61 After
i386: arch/x86/kernel/process.o
text data bss dec hex
2957 8673 8 11638 2d76 Before
2925 8673 8 11606 2d56 After
Originally-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Kyle Huey <khuey@kylehuey.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Link: http://lkml.kernel.org/r/20170214081104.9244-2-khuey@kylehuey.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 3.16:
- We don't do refresh_tr_limit() here
- Use ACCESS_ONCE() instead of READ_ONCE()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Kees Cook [Wed, 25 Jun 2014 23:08:24 +0000 (16:08 -0700)]
seccomp: add "seccomp" syscall
commit
48dc92b9fc3926844257316e75ba11eb5c742b2c upstream.
This adds the new "seccomp" syscall with both an "operation" and "flags"
parameter for future expansion. The third argument is a pointer value,
used with the SECCOMP_SET_MODE_FILTER operation. Currently, flags must
be 0. This is functionally equivalent to prctl(PR_SET_SECCOMP, ...).
In addition to the TSYNC flag later in this patch series, there is a
non-zero chance that this syscall could be used for configuring a fixed
argument area for seccomp-tracer-aware processes to pass syscall arguments
in the future. Hence, the use of "seccomp" not simply "seccomp_add_filter"
for this syscall. Additionally, this syscall uses operation, flags,
and user pointer for arguments because strictly passing arguments via
a user pointer would mean seccomp itself would be unable to trivially
filter the seccomp syscall itself.
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Kees Cook [Wed, 25 Jun 2014 22:55:25 +0000 (15:55 -0700)]
seccomp: split mode setting routines
commit
3b23dd12846215eff4afb073366b80c0c4d7543e upstream.
Separates the two mode setting paths to make things more readable with
fewer #ifdefs within function bodies.
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Kees Cook [Wed, 25 Jun 2014 22:38:02 +0000 (15:38 -0700)]
seccomp: extract check/assign mode helpers
commit
1f41b450416e689b9b7c8bfb750a98604f687a9b upstream.
To support splitting mode 1 from mode 2, extract the mode checking and
assignment logic into common functions.
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Kees Cook [Wed, 21 May 2014 22:02:11 +0000 (15:02 -0700)]
seccomp: create internal mode-setting function
commit
d78ab02c2c194257a03355fbb79eb721b381d105 upstream.
In preparation for having other callers of the seccomp mode setting
logic, split the prctl entry point away from the core logic that performs
seccomp mode setting.
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Eric Sandeen [Fri, 8 Jun 2018 16:53:49 +0000 (09:53 -0700)]
xfs: don't call xfs_da_shrink_inode with NULL bp
commit
bb3d48dcf86a97dc25fe9fc2c11938e19cb4399a upstream.
xfs_attr3_leaf_create may have errored out before instantiating a buffer,
for example if the blkno is out of range. In that case there is no work
to do to remove it, and in fact xfs_da_shrink_inode will lead to an oops
if we try.
This also seems to fix a flaw where the original error from
xfs_attr3_leaf_create gets overwritten in the cleanup case, and it
removes a pointless assignment to bp which isn't used after this.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199969
Reported-by: Xu, Wen <wen.xu@gatech.edu>
Tested-by: Xu, Wen <wen.xu@gatech.edu>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Dave Chinner [Wed, 18 Apr 2018 00:17:34 +0000 (17:17 -0700)]
xfs: validate cached inodes are free when allocated
commit
afca6c5b2595fc44383919fba740c194b0b76aff upstream.
A recent fuzzed filesystem image cached random dcache corruption
when the reproducer was run. This often showed up as panics in
lookup_slow() on a null inode->i_ops pointer when doing pathwalks.
BUG: unable to handle kernel NULL pointer dereference at
0000000000000000
....
Call Trace:
lookup_slow+0x44/0x60
walk_component+0x3dd/0x9f0
link_path_walk+0x4a7/0x830
path_lookupat+0xc1/0x470
filename_lookup+0x129/0x270
user_path_at_empty+0x36/0x40
path_listxattr+0x98/0x110
SyS_listxattr+0x13/0x20
do_syscall_64+0xf5/0x280
entry_SYSCALL_64_after_hwframe+0x42/0xb7
but had many different failure modes including deadlocks trying to
lock the inode that was just allocated or KASAN reports of
use-after-free violations.
The cause of the problem was a corrupt INOBT on a v4 fs where the
root inode was marked as free in the inobt record. Hence when we
allocated an inode, it chose the root inode to allocate, found it in
the cache and re-initialised it.
We recently fixed a similar inode allocation issue caused by inobt
record corruption problem in xfs_iget_cache_miss() in commit
ee457001ed6c ("xfs: catch inode allocation state mismatch
corruption"). This change adds similar checks to the cache-hit path
to catch it, and turns the reproducer into a corruption shutdown
situation.
Reported-by: Wen Xu <wen.xu@gatech.edu>
Signed-Off-By: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
[darrick: fix typos in comment]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
[bwh: Backported to 3.16:
- Look up mode in XFS inode, not VFS inode
- Use positive error codes]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Dave Chinner [Fri, 23 Mar 2018 17:22:53 +0000 (10:22 -0700)]
xfs: catch inode allocation state mismatch corruption
commit
ee457001ed6c6f31ddad69c24c1da8f377d8472d upstream.
We recently came across a V4 filesystem causing memory corruption
due to a newly allocated inode being setup twice and being added to
the superblock inode list twice. From code inspection, the only way
this could happen is if a newly allocated inode was not marked as
free on disk (i.e. di_mode wasn't zero).
Running the metadump on an upstream debug kernel fails during inode
allocation like so:
XFS: Assertion failed: ip->i_d.di_nblocks == 0, file: fs/xfs/xfs_inod=
e.c, line: 838
------------[ cut here ]------------
kernel BUG at fs/xfs/xfs_message.c:114!
invalid opcode: 0000 [#1] PREEMPT SMP
CPU: 11 PID: 3496 Comm: mkdir Not tainted 4.16.0-rc5-dgc #442
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/0=
1/2014
RIP: 0010:assfail+0x28/0x30
RSP: 0018:
ffffc9000236fc80 EFLAGS:
00010202
RAX:
00000000ffffffea RBX:
0000000000004000 RCX:
0000000000000000
RDX:
00000000ffffffc0 RSI:
000000000000000a RDI:
ffffffff8227211b
RBP:
ffffc9000236fce8 R08:
0000000000000000 R09:
0000000000000000
R10:
0000000000000bec R11:
f000000000000000 R12:
ffffc9000236fd30
R13:
ffff8805c76bab80 R14:
ffff8805c77ac800 R15:
ffff88083fb12e10
FS:
00007fac8cbff040(0000) GS:
ffff88083fd00000(0000) knlGS:
0000000000000=
000
CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
CR2:
00007fffa6783ff8 CR3:
00000005c6e2b003 CR4:
00000000000606e0
Call Trace:
xfs_ialloc+0x383/0x570
xfs_dir_ialloc+0x6a/0x2a0
xfs_create+0x412/0x670
xfs_generic_create+0x1f7/0x2c0
? capable_wrt_inode_uidgid+0x3f/0x50
vfs_mkdir+0xfb/0x1b0
SyS_mkdir+0xcf/0xf0
do_syscall_64+0x73/0x1a0
entry_SYSCALL_64_after_hwframe+0x42/0xb7
Extracting the inode number we crashed on from an event trace and
looking at it with xfs_db:
xfs_db> inode
184452204
xfs_db> p
core.magic = 0x494e
core.mode =
0100644
core.version = 2
core.format = 2 (extents)
core.nlinkv2 = 1
core.onlink = 0
.....
Confirms that it is not a free inode on disk. xfs_repair
also trips over this inode:
.....
zero length extent (off = 0, fsbno = 0) in ino
184452204
correcting nextents for inode
184452204
bad attribute fork in inode
184452204, would clear attr fork
bad nblocks 1 for inode
184452204, would reset to 0
bad anextents 1 for inode
184452204, would reset to 0
imap claims in-use inode
184452204 is free, would correct imap
would have cleared inode
184452204
.....
disconnected inode
184452204, would move to lost+found
And so we have a situation where the directory structure and the
inobt thinks the inode is free, but the inode on disk thinks it is
still in use. Where this corruption came from is not possible to
diagnose, but we can detect it and prevent the kernel from oopsing
on lookup. The reproducer now results in:
$ sudo mkdir /mnt/scratch/{0,1,2,3,4,5}{0,1,2,3,4,5}
mkdir: cannot create directory =E2=80=98/mnt/scratch/00=E2=80=99: File ex=
ists
mkdir: cannot create directory =E2=80=98/mnt/scratch/01=E2=80=99: File ex=
ists
mkdir: cannot create directory =E2=80=98/mnt/scratch/03=E2=80=99: Structu=
re needs cleaning
mkdir: cannot create directory =E2=80=98/mnt/scratch/04=E2=80=99: Input/o=
utput error
mkdir: cannot create directory =E2=80=98/mnt/scratch/05=E2=80=99: Input/o=
utput error
....
And this corruption shutdown:
[ 54.843517] XFS (loop0): Corruption detected! Free inode 0xafe846c not=
marked free on disk
[ 54.845885] XFS (loop0): Internal error xfs_trans_cancel at line 1023 =
of file fs/xfs/xfs_trans.c. Caller xfs_create+0x425/0x670
[ 54.848994] CPU: 10 PID: 3541 Comm: mkdir Not tainted 4.16.0-rc5-dgc #=
443
[ 54.850753] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIO=
S 1.10.2-1 04/01/2014
[ 54.852859] Call Trace:
[ 54.853531] dump_stack+0x85/0xc5
[ 54.854385] xfs_trans_cancel+0x197/0x1c0
[ 54.855421] xfs_create+0x425/0x670
[ 54.856314] xfs_generic_create+0x1f7/0x2c0
[ 54.857390] ? capable_wrt_inode_uidgid+0x3f/0x50
[ 54.858586] vfs_mkdir+0xfb/0x1b0
[ 54.859458] SyS_mkdir+0xcf/0xf0
[ 54.860254] do_syscall_64+0x73/0x1a0
[ 54.861193] entry_SYSCALL_64_after_hwframe+0x42/0xb7
[ 54.862492] RIP: 0033:0x7fb73bddf547
[ 54.863358] RSP: 002b:
00007ffdaa553338 EFLAGS:
00000246 ORIG_RAX: 0000=
000000000053
[ 54.865133] RAX:
ffffffffffffffda RBX:
00007ffdaa55449a RCX:
00007fb73=
bddf547
[ 54.866766] RDX:
0000000000000001 RSI:
00000000000001ff RDI:
00007ffda=
a55449a
[ 54.868432] RBP:
00007ffdaa55449a R08:
00000000000001ff R09:
00005623a=
8670dd0
[ 54.870110] R10:
00007fb73be72d5b R11:
0000000000000246 R12:
000000000=
00001ff
[ 54.871752] R13:
00007ffdaa5534b0 R14:
0000000000000000 R15:
00007ffda=
a553500
[ 54.873429] XFS (loop0): xfs_do_force_shutdown(0x8) called from line 1=
024 of file fs/xfs/xfs_trans.c. Return address =
ffffffff814cd050
[ 54.882790] XFS (loop0): Corruption of in-memory data detected. Shutt=
ing down filesystem
[ 54.884597] XFS (loop0): Please umount the filesystem and rectify the =
problem(s)
Note that this crash is only possible on v4 filesystemsi or v5
filesystems mounted with the ikeep mount option. For all other V5
filesystems, this problem cannot occur because we don't read inodes
we are allocating from disk - we simply overwrite them with the new
inode information.
Signed-Off-By: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Tested-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
[bwh: Backported to 3.16:
- Look up mode in XFS inode, not VFS inode
- Use positive error codes]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Ernesto A. Fernández [Fri, 24 Aug 2018 00:00:25 +0000 (17:00 -0700)]
hfsplus: fix NULL dereference in hfsplus_lookup()
commit
a7ec7a4193a2eb3b5341243fc0b621c1ac9e4ec4 upstream.
An HFS+ filesystem can be mounted read-only without having a metadata
directory, which is needed to support hardlinks. But if the catalog
data is corrupted, a directory lookup may still find dentries claiming
to be hardlinks.
hfsplus_lookup() does check that ->hidden_dir is not NULL in such a
situation, but mistakenly does so after dereferencing it for the first
time. Reorder this check to prevent a crash.
This happens when looking up corrupted catalog data (dentry) on a
filesystem with no metadata directory (this could only ever happen on a
read-only mount). Wen Xu sent the replication steps in detail to the
fsdevel list: https://bugzilla.kernel.org/show_bug.cgi?id=200297
Link: http://lkml.kernel.org/r/20180712215344.q44dyrhymm4ajkao@eaf
Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Reported-by: Wen Xu <wen.xu@gatech.edu>
Cc: Viacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Qu Wenruo [Tue, 3 Jul 2018 09:10:07 +0000 (17:10 +0800)]
btrfs: relocation: Only remove reloc rb_trees if reloc control has been initialized
commit
389305b2aa68723c754f88d9dbd268a400e10664 upstream.
Invalid reloc tree can cause kernel NULL pointer dereference when btrfs
does some cleanup of the reloc roots.
It turns out that fs_info::reloc_ctl can be NULL in
btrfs_recover_relocation() as we allocate relocation control after all
reloc roots have been verified.
So when we hit: note, we haven't called set_reloc_control() thus
fs_info::reloc_ctl is still NULL.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=199833
Reported-by: Xu Wen <wen.xu@gatech.edu>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Tested-by: Gu Jinxiang <gujx@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Kees Cook [Fri, 11 May 2018 08:24:12 +0000 (18:24 +1000)]
video: uvesafb: Fix integer overflow in allocation
commit
9f645bcc566a1e9f921bdae7528a01ced5bc3713 upstream.
cmap->len can get close to INT_MAX/2, allowing for an integer overflow in
allocation. This uses kmalloc_array() instead to catch the condition.
Reported-by: Dr Silvio Cesare of InfoSect <silvio.cesare@gmail.com>
Fixes: 8bdb3a2d7df48 ("uvesafb: the driver core")
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Sanjeev Sharma [Tue, 12 Aug 2014 06:40:21 +0000 (12:10 +0530)]
uas: replace WARN_ON_ONCE() with lockdep_assert_held()
commit
ab945eff8396bc3329cc97274320e8d2c6585077 upstream.
on some architecture spin_is_locked() always return false in
uniprocessor configuration and therefore it would be advise
to replace with lockdep_assert_held().
Signed-off-by: Sanjeev Sharma <Sanjeev_Sharma@mentor.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Scott Bauer [Thu, 26 Apr 2018 17:51:08 +0000 (11:51 -0600)]
cdrom: Fix info leak/OOB read in cdrom_ioctl_drive_status
commit
8f3fafc9c2f0ece10832c25f7ffcb07c97a32ad4 upstream.
Like
d88b6d04: "cdrom: information leak in cdrom_ioctl_media_changed()"
There is another cast from unsigned long to int which causes
a bounds check to fail with specially crafted input. The value is
then used as an index in the slot array in cdrom_slot_status().
Signed-off-by: Scott Bauer <scott.bauer@intel.com>
Signed-off-by: Scott Bauer <sbauer@plzdonthack.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Peter Zijlstra [Fri, 3 Aug 2018 14:41:39 +0000 (16:41 +0200)]
x86/paravirt: Fix spectre-v2 mitigations for paravirt guests
commit
5800dc5c19f34e6e03b5adab1282535cb102fafd upstream.
Nadav reported that on guests we're failing to rewrite the indirect
calls to CALLEE_SAVE paravirt functions. In particular the
pv_queued_spin_unlock() call is left unpatched and that is all over the
place. This obviously wrecks Spectre-v2 mitigation (for paravirt
guests) which relies on not actually having indirect calls around.
The reason is an incorrect clobber test in paravirt_patch_call(); this
function rewrites an indirect call with a direct call to the _SAME_
function, there is no possible way the clobbers can be different
because of this.
Therefore remove this clobber check. Also put WARNs on the other patch
failure case (not enough room for the instruction) which I've not seen
trigger in my (limited) testing.
Three live kernel image disassemblies for lock_sock_nested (as a small
function that illustrates the problem nicely). PRE is the current
situation for guests, POST is with this patch applied and NATIVE is with
or without the patch for !guests.
PRE:
(gdb) disassemble lock_sock_nested
Dump of assembler code for function lock_sock_nested:
0xffffffff817be970 <+0>: push %rbp
0xffffffff817be971 <+1>: mov %rdi,%rbp
0xffffffff817be974 <+4>: push %rbx
0xffffffff817be975 <+5>: lea 0x88(%rbp),%rbx
0xffffffff817be97c <+12>: callq 0xffffffff819f7160 <_cond_resched>
0xffffffff817be981 <+17>: mov %rbx,%rdi
0xffffffff817be984 <+20>: callq 0xffffffff819fbb00 <_raw_spin_lock_bh>
0xffffffff817be989 <+25>: mov 0x8c(%rbp),%eax
0xffffffff817be98f <+31>: test %eax,%eax
0xffffffff817be991 <+33>: jne 0xffffffff817be9ba <lock_sock_nested+74>
0xffffffff817be993 <+35>: movl $0x1,0x8c(%rbp)
0xffffffff817be99d <+45>: mov %rbx,%rdi
0xffffffff817be9a0 <+48>: callq *0xffffffff822299e8
0xffffffff817be9a7 <+55>: pop %rbx
0xffffffff817be9a8 <+56>: pop %rbp
0xffffffff817be9a9 <+57>: mov $0x200,%esi
0xffffffff817be9ae <+62>: mov $0xffffffff817be993,%rdi
0xffffffff817be9b5 <+69>: jmpq 0xffffffff81063ae0 <__local_bh_enable_ip>
0xffffffff817be9ba <+74>: mov %rbp,%rdi
0xffffffff817be9bd <+77>: callq 0xffffffff817be8c0 <__lock_sock>
0xffffffff817be9c2 <+82>: jmp 0xffffffff817be993 <lock_sock_nested+35>
End of assembler dump.
POST:
(gdb) disassemble lock_sock_nested
Dump of assembler code for function lock_sock_nested:
0xffffffff817be970 <+0>: push %rbp
0xffffffff817be971 <+1>: mov %rdi,%rbp
0xffffffff817be974 <+4>: push %rbx
0xffffffff817be975 <+5>: lea 0x88(%rbp),%rbx
0xffffffff817be97c <+12>: callq 0xffffffff819f7160 <_cond_resched>
0xffffffff817be981 <+17>: mov %rbx,%rdi
0xffffffff817be984 <+20>: callq 0xffffffff819fbb00 <_raw_spin_lock_bh>
0xffffffff817be989 <+25>: mov 0x8c(%rbp),%eax
0xffffffff817be98f <+31>: test %eax,%eax
0xffffffff817be991 <+33>: jne 0xffffffff817be9ba <lock_sock_nested+74>
0xffffffff817be993 <+35>: movl $0x1,0x8c(%rbp)
0xffffffff817be99d <+45>: mov %rbx,%rdi
0xffffffff817be9a0 <+48>: callq 0xffffffff810a0c20 <__raw_callee_save___pv_queued_spin_unlock>
0xffffffff817be9a5 <+53>: xchg %ax,%ax
0xffffffff817be9a7 <+55>: pop %rbx
0xffffffff817be9a8 <+56>: pop %rbp
0xffffffff817be9a9 <+57>: mov $0x200,%esi
0xffffffff817be9ae <+62>: mov $0xffffffff817be993,%rdi
0xffffffff817be9b5 <+69>: jmpq 0xffffffff81063aa0 <__local_bh_enable_ip>
0xffffffff817be9ba <+74>: mov %rbp,%rdi
0xffffffff817be9bd <+77>: callq 0xffffffff817be8c0 <__lock_sock>
0xffffffff817be9c2 <+82>: jmp 0xffffffff817be993 <lock_sock_nested+35>
End of assembler dump.
NATIVE:
(gdb) disassemble lock_sock_nested
Dump of assembler code for function lock_sock_nested:
0xffffffff817be970 <+0>: push %rbp
0xffffffff817be971 <+1>: mov %rdi,%rbp
0xffffffff817be974 <+4>: push %rbx
0xffffffff817be975 <+5>: lea 0x88(%rbp),%rbx
0xffffffff817be97c <+12>: callq 0xffffffff819f7160 <_cond_resched>
0xffffffff817be981 <+17>: mov %rbx,%rdi
0xffffffff817be984 <+20>: callq 0xffffffff819fbb00 <_raw_spin_lock_bh>
0xffffffff817be989 <+25>: mov 0x8c(%rbp),%eax
0xffffffff817be98f <+31>: test %eax,%eax
0xffffffff817be991 <+33>: jne 0xffffffff817be9ba <lock_sock_nested+74>
0xffffffff817be993 <+35>: movl $0x1,0x8c(%rbp)
0xffffffff817be99d <+45>: mov %rbx,%rdi
0xffffffff817be9a0 <+48>: movb $0x0,(%rdi)
0xffffffff817be9a3 <+51>: nopl 0x0(%rax)
0xffffffff817be9a7 <+55>: pop %rbx
0xffffffff817be9a8 <+56>: pop %rbp
0xffffffff817be9a9 <+57>: mov $0x200,%esi
0xffffffff817be9ae <+62>: mov $0xffffffff817be993,%rdi
0xffffffff817be9b5 <+69>: jmpq 0xffffffff81063ae0 <__local_bh_enable_ip>
0xffffffff817be9ba <+74>: mov %rbp,%rdi
0xffffffff817be9bd <+77>: callq 0xffffffff817be8c0 <__lock_sock>
0xffffffff817be9c2 <+82>: jmp 0xffffffff817be993 <lock_sock_nested+35>
End of assembler dump.
Fixes: 63f70270ccd9 ("[PATCH] i386: PARAVIRT: add common patching machinery")
Fixes: 3010a0663fd9 ("x86/paravirt, objtool: Annotate indirect calls")
Reported-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Jiri Kosina [Thu, 26 Jul 2018 11:14:55 +0000 (13:14 +0200)]
x86/speculation: Protect against userspace-userspace spectreRSB
commit
fdf82a7856b32d905c39afc85e34364491e46346 upstream.
The article "Spectre Returns! Speculation Attacks using the Return Stack
Buffer" [1] describes two new (sub-)variants of spectrev2-like attacks,
making use solely of the RSB contents even on CPUs that don't fallback to
BTB on RSB underflow (Skylake+).
Mitigate userspace-userspace attacks by always unconditionally filling RSB on
context switch when the generic spectrev2 mitigation has been enabled.
[1] https://arxiv.org/pdf/1807.07940.pdf
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lkml.kernel.org/r/nycvar.YFH.7.76.1807261308190.997@cbobk.fhfr.pm
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Ingo Molnar [Tue, 13 Feb 2018 08:03:08 +0000 (09:03 +0100)]
x86/speculation: Clean up various Spectre related details
commit
21e433bdb95bdf3aa48226fd3d33af608437f293 upstream.
Harmonize all the Spectre messages so that a:
dmesg | grep -i spectre
... gives us most Spectre related kernel boot messages.
Also fix a few other details:
- clarify a comment about firmware speculation control
- s/KPTI/PTI
- remove various line-breaks that made the code uglier
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Takashi Iwai [Tue, 17 Jul 2018 15:26:43 +0000 (17:26 +0200)]
ALSA: rawmidi: Change resized buffers atomically
commit
39675f7a7c7e7702f7d5341f1e0d01db746543a0 upstream.
The SNDRV_RAWMIDI_IOCTL_PARAMS ioctl may resize the buffers and the
current code is racy. For example, the sequencer client may write to
buffer while it being resized.
As a simple workaround, let's switch to the resized buffer inside the
stream runtime lock.
Reported-by: syzbot+52f83f0ea8df16932f7f@syzkaller.appspotmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Jann Horn [Fri, 6 Jul 2018 15:12:56 +0000 (17:12 +0200)]
USB: yurex: fix out-of-bounds uaccess in read handler
commit
f1e255d60ae66a9f672ff9a207ee6cd8e33d2679 upstream.
In general, accessing userspace memory beyond the length of the supplied
buffer in VFS read/write handlers can lead to both kernel memory corruption
(via kernel_read()/kernel_write(), which can e.g. be triggered via
sys_splice()) and privilege escalation inside userspace.
Fix it by using simple_read_from_buffer() instead of custom logic.
Fixes: 6bc235a2e24a ("USB: add driver for Meywa-Denki & Kayac YUREX")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cong Wang [Fri, 1 Jun 2018 18:31:44 +0000 (11:31 -0700)]
infiniband: fix a possible use-after-free bug
commit
cb2595c1393b4a5211534e6f0a0fbad369e21ad8 upstream.
ucma_process_join() will free the new allocated "mc" struct,
if there is any error after that, especially the copy_to_user().
But in parallel, ucma_leave_multicast() could find this "mc"
through idr_find() before ucma_process_join() frees it, since it
is already published.
So "mc" could be used in ucma_leave_multicast() after it is been
allocated and freed in ucma_process_join(), since we don't refcnt
it.
Fix this by separating "publish" from ID allocation, so that we
can get an ID first and publish it later after copy_to_user().
Fixes: c8f6a362bf3e ("RDMA/cma: Add multicast communication support")
Reported-by: Noam Rathaus <noamr@beyondsecurity.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Andy Lutomirski [Sun, 22 Jul 2018 18:05:09 +0000 (11:05 -0700)]
x86/entry/64: Remove %ebx handling from error_entry/exit
commit
b3681dd548d06deb2e1573890829dff4b15abf46 upstream.
error_entry and error_exit communicate the user vs. kernel status of
the frame using %ebx. This is unnecessary -- the information is in
regs->cs. Just use regs->cs.
This makes error_entry simpler and makes error_exit more robust.
It also fixes a nasty bug. Before all the Spectre nonsense, the
xen_failsafe_callback entry point returned like this:
ALLOC_PT_GPREGS_ON_STACK
SAVE_C_REGS
SAVE_EXTRA_REGS
ENCODE_FRAME_POINTER
jmp error_exit
And it did not go through error_entry. This was bogus: RBX
contained garbage, and error_exit expected a flag in RBX.
Fortunately, it generally contained *nonzero* garbage, so the
correct code path was used. As part of the Spectre fixes, code was
added to clear RBX to mitigate certain speculation attacks. Now,
depending on kernel configuration, RBX got zeroed and, when running
some Wine workloads, the kernel crashes. This was introduced by:
commit
3ac6d8c787b8 ("x86/entry/64: Clear registers for exceptions/interrupts, to reduce speculation attack surface")
With this patch applied, RBX is no longer needed as a flag, and the
problem goes away.
I suspect that malicious userspace could use this bug to crash the
kernel even without the offending patch applied, though.
[ Historical note: I wrote this patch as a cleanup before I was aware
of the bug it fixed. ]
[ Note to stable maintainers: this should probably get applied to all
kernels. If you're nervous about that, a more conservative fix to
add xorl %ebx,%ebx; incl %ebx before the jump to error_exit should
also fix the problem. ]
Reported-and-tested-by: M. Vefa Bicakci <m.v.b@runbox.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: xen-devel@lists.xenproject.org
Fixes: 3ac6d8c787b8 ("x86/entry/64: Clear registers for exceptions/interrupts, to reduce speculation attack surface")
Link: http://lkml.kernel.org/r/b5010a090d3586b2d6e06c7ad3ec5542d1241c45.1532282627.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.16:
- error_exit moved EBX to EAX before testing it, so delete both instructions
- error_exit does RESTORE_REST earlier, so adjust the offset to saved CS
accordingly
- Drop inapplicable comment changes
- Adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Linus Torvalds [Wed, 4 Jul 2018 00:10:19 +0000 (17:10 -0700)]
Fix up non-directory creation in SGID directories
commit
0fa3ecd87848c9c93c2c828ef4c3a8ca36ce46c7 upstream.
sgid directories have special semantics, making newly created files in
the directory belong to the group of the directory, and newly created
subdirectories will also become sgid. This is historically used for
group-shared directories.
But group directories writable by non-group members should not imply
that such non-group members can magically join the group, so make sure
to clear the sgid bit on non-directories for non-members (but remember
that sgid without group execute means "mandatory locking", just to
confuse things even more).
Reported-by: Jann Horn <jannh@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Theodore Ts'o [Sun, 17 Jun 2018 03:41:59 +0000 (23:41 -0400)]
ext4: avoid running out of journal credits when appending to an inline file
commit
8bc1379b82b8e809eef77a9fedbb75c6c297be19 upstream.
Use a separate journal transaction if it turns out that we need to
convert an inline file to use an data block. Otherwise we could end
up failing due to not having journal credits.
This addresses CVE-2018-10883.
https://bugzilla.kernel.org/show_bug.cgi?id=200071
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Theodore Ts'o [Sun, 17 Jun 2018 00:21:45 +0000 (20:21 -0400)]
jbd2: don't mark block as modified if the handle is out of credits
commit
e09463f220ca9a1a1ecfda84fcda658f99a1f12a upstream.
Do not set the b_modified flag in block's journal head should not
until after we're sure that jbd2_journal_dirty_metadat() will not
abort with an error due to there not being enough space reserved in
the jbd2 handle.
Otherwise, future attempts to modify the buffer may lead a large
number of spurious errors and warnings.
This addresses CVE-2018-10883.
https://bugzilla.kernel.org/show_bug.cgi?id=200071
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16: Drop the added logging statement, as it's on
a code path that doesn't exist here]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Theodore Ts'o [Sun, 17 Jun 2018 04:41:14 +0000 (00:41 -0400)]
ext4: add more inode number paranoia checks
commit
c37e9e013469521d9adb932d17a1795c139b36db upstream.
If there is a directory entry pointing to a system inode (such as a
journal inode), complain and declare the file system to be corrupted.
Also, if the superblock's first inode number field is too small,
refuse to mount the file system.
This addresses CVE-2018-10882.
https://bugzilla.kernel.org/show_bug.cgi?id=200069
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Theodore Ts'o [Fri, 15 Jun 2018 16:28:16 +0000 (12:28 -0400)]
ext4: clear i_data in ext4_inode_info when removing inline data
commit
6e8ab72a812396996035a37e5ca4b3b99b5d214b upstream.
When converting from an inode from storing the data in-line to a data
block, ext4_destroy_inline_data_nolock() was only clearing the on-disk
copy of the i_blocks[] array. It was not clearing copy of the
i_blocks[] in ext4_inode_info, in i_data[], which is the copy actually
used by ext4_map_blocks().
This didn't matter much if we are using extents, since the extents
header would be invalid and thus the extents could would re-initialize
the extents tree. But if we are using indirect blocks, the previous
contents of the i_blocks array will be treated as block numbers, with
potentially catastrophic results to the file system integrity and/or
user data.
This gets worse if the file system is using a 1k block size and
s_first_data is zero, but even without this, the file system can get
quite badly corrupted.
This addresses CVE-2018-10881.
https://bugzilla.kernel.org/show_bug.cgi?id=200015
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Theodore Ts'o [Sat, 16 Jun 2018 19:40:48 +0000 (15:40 -0400)]
ext4: never move the system.data xattr out of the inode body
commit
8cdb5240ec5928b20490a2bb34cb87e9a5f40226 upstream.
When expanding the extra isize space, we must never move the
system.data xattr out of the inode body. For performance reasons, it
doesn't make any sense, and the inline data implementation assumes
that system.data xattr is never in the external xattr block.
This addresses CVE-2018-10880
https://bugzilla.kernel.org/show_bug.cgi?id=200005
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Theodore Ts'o [Wed, 13 Jun 2018 04:51:28 +0000 (00:51 -0400)]
ext4: always verify the magic number in xattr blocks
commit
513f86d73855ce556ea9522b6bfd79f87356dc3a upstream.
If there an inode points to a block which is also some other type of
metadata block (such as a block allocation bitmap), the
buffer_verified flag can be set when it was validated as that other
metadata block type; however, it would make a really terrible external
attribute block. The reason why we use the verified flag is to avoid
constantly reverifying the block. However, it doesn't take much
overhead to make sure the magic number of the xattr block is correct,
and this will avoid potential crashes.
This addresses CVE-2018-10879.
https://bugzilla.kernel.org/show_bug.cgi?id=200001
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Theodore Ts'o [Wed, 13 Jun 2018 04:23:11 +0000 (00:23 -0400)]
ext4: add corruption check in ext4_xattr_set_entry()
commit
5369a762c882c0b6e9599e4ebbb3a9ba9eee7e2d upstream.
In theory this should have been caught earlier when the xattr list was
verified, but in case it got missed, it's simple enough to add check
to make sure we don't overrun the xattr buffer.
This addresses CVE-2018-10879.
https://bugzilla.kernel.org/show_bug.cgi?id=200001
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
[bwh: Backported to 3.16:
- Add inode parameter to ext4_xattr_set_entry() and update callers
- Return -EIO instead of -EFSCORRUPTED on error
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Theodore Ts'o [Sun, 8 Jul 2018 23:35:02 +0000 (19:35 -0400)]
ext4: fix false negatives *and* false positives in ext4_check_descriptors()
commit
44de022c4382541cebdd6de4465d1f4f465ff1dd upstream.
Ext4_check_descriptors() was getting called before s_gdb_count was
initialized. So for file systems w/o the meta_bg feature, allocation
bitmaps could overlap the block group descriptors and ext4 wouldn't
notice.
For file systems with the meta_bg feature enabled, there was a
fencepost error which would cause the ext4_check_descriptors() to
incorrectly believe that the block allocation bitmap overlaps with the
block group descriptor blocks, and it would reject the mount.
Fix both of these problems.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Theodore Ts'o [Thu, 14 Jun 2018 03:08:26 +0000 (23:08 -0400)]
ext4: make sure bitmaps and the inode table don't overlap with bg descriptors
commit
77260807d1170a8cf35dbb06e07461a655f67eee upstream.
It's really bad when the allocation bitmaps and the inode table
overlap with the block group descriptors, since it causes random
corruption of the bg descriptors. So we really want to head those off
at the pass.
https://bugzilla.kernel.org/show_bug.cgi?id=199865
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16: Open-code sb_rdonly()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Theodore Ts'o [Fri, 30 Mar 2018 02:10:35 +0000 (22:10 -0400)]
ext4: don't allow r/w mounts if metadata blocks overlap the superblock
commit
18db4b4e6fc31eda838dd1c1296d67dbcb3dc957 upstream.
If some metadata block, such as an allocation bitmap, overlaps the
superblock, it's very likely that if the file system is mounted
read/write, the results will not be pretty. So disallow r/w mounts
for file systems corrupted in this particular way.
Backport notes:
3.18.y is missing
bc98a42c1f7d ("VFS: Convert sb->s_flags & MS_RDONLY
to sb_rdonly(sb)") and
e462ec50cb5f ("VFS: Differentiate mount flags
(MS_*) from internal superblock flags") so we simply use the sb
MS_RDONLY check from pre
bc98a42c1f7d in place of the sb_rdonly
function used in the upstream variant of the patch.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Harsh Shandilya <harsh@prjkt.io>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Theodore Ts'o [Thu, 14 Jun 2018 03:00:48 +0000 (23:00 -0400)]
ext4: always check block group bounds in ext4_init_block_bitmap()
commit
819b23f1c501b17b9694325471789e6b5cc2d0d2 upstream.
Regardless of whether the flex_bg feature is set, we should always
check to make sure the bits we are setting in the block bitmap are
within the block group bounds.
https://bugzilla.kernel.org/show_bug.cgi?id=199865
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Theodore Ts'o [Thu, 14 Jun 2018 16:55:10 +0000 (12:55 -0400)]
ext4: verify the depth of extent tree in ext4_find_extent()
commit
bc890a60247171294acc0bd67d211fa4b88d40ba upstream.
If there is a corupted file system where the claimed depth of the
extent tree is -1, this can cause a massive buffer overrun leading to
sadness.
This addresses CVE-2018-10877.
https://bugzilla.kernel.org/show_bug.cgi?id=199417
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16: return -EIO instead of -EFSCORRUPTED]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Theodore Ts'o [Sat, 28 Jul 2018 12:12:04 +0000 (08:12 -0400)]
ext4: fix check to prevent initializing reserved inodes
commit
5012284700775a4e6e3fbe7eac4c543c4874b559 upstream.
Commit
8844618d8aa7: "ext4: only look at the bg_flags field if it is
valid" will complain if block group zero does not have the
EXT4_BG_INODE_ZEROED flag set. Unfortunately, this is not correct,
since a freshly created file system has this flag cleared. It gets
almost immediately after the file system is mounted read-write --- but
the following somewhat unlikely sequence will end up triggering a
false positive report of a corrupted file system:
mkfs.ext4 /dev/vdc
mount -o ro /dev/vdc /vdc
mount -o remount,rw /dev/vdc
Instead, when initializing the inode table for block group zero, test
to make sure that itable_unused count is not too large, since that is
the case that will result in some or all of the reserved inodes
getting cleared.
This fixes the failures reported by Eric Whiteney when running
generic/230 and generic/231 in the the nojournal test case.
Fixes: 8844618d8aa7 ("ext4: only look at the bg_flags field if it is valid")
Reported-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Theodore Ts'o [Thu, 14 Jun 2018 04:58:00 +0000 (00:58 -0400)]
ext4: only look at the bg_flags field if it is valid
commit
8844618d8aa7a9973e7b527d038a2a589665002c upstream.
The bg_flags field in the block group descripts is only valid if the
uninit_bg or metadata_csum feature is enabled. We were not
consistently looking at this field; fix this.
Also block group #0 must never have uninitialized allocation bitmaps,
or need to be zeroed, since that's where the root inode, and other
special inodes are set up. Check for these conditions and mark the
file system as corrupted if they are detected.
This addresses CVE-2018-10876.
https://bugzilla.kernel.org/show_bug.cgi?id=199403
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16:
- ext4_read_block_bitmap_nowait() and ext4_read_inode_bitmap() return
a pointer (NULL on error) instead of an error code
- Open-code sb_rdonly()
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Eric Sandeen [Tue, 17 Apr 2018 06:07:27 +0000 (23:07 -0700)]
xfs: set format back to extents if xfs_bmap_extents_to_btree
commit
2c4306f719b083d17df2963bc761777576b8ad1b upstream.
If xfs_bmap_extents_to_btree fails in a mode where we call
xfs_iroot_realloc(-1) to de-allocate the root, set the
format back to extents.
Otherwise we can assume we can dereference ifp->if_broot
based on the XFS_DINODE_FMT_BTREE format, and crash.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199423
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
[bwh: Backported to 3.16:
- Only one failure path needs to be patched
- Adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Jason Yan [Thu, 8 Mar 2018 02:34:53 +0000 (10:34 +0800)]
scsi: libsas: defer ata device eh commands to libata
commit
318aaf34f1179b39fa9c30fa0f3288b645beee39 upstream.
When ata device doing EH, some commands still attached with tasks are
not passed to libata when abort failed or recover failed, so libata did
not handle these commands. After these commands done, sas task is freed,
but ata qc is not freed. This will cause ata qc leak and trigger a
warning like below:
WARNING: CPU: 0 PID: 28512 at drivers/ata/libata-eh.c:4037
ata_eh_finish+0xb4/0xcc
CPU: 0 PID: 28512 Comm: kworker/u32:2 Tainted: G W OE 4.14.0#1
......
Call trace:
[<
ffff0000088b7bd0>] ata_eh_finish+0xb4/0xcc
[<
ffff0000088b8420>] ata_do_eh+0xc4/0xd8
[<
ffff0000088b8478>] ata_std_error_handler+0x44/0x8c
[<
ffff0000088b8068>] ata_scsi_port_error_handler+0x480/0x694
[<
ffff000008875fc4>] async_sas_ata_eh+0x4c/0x80
[<
ffff0000080f6be8>] async_run_entry_fn+0x4c/0x170
[<
ffff0000080ebd70>] process_one_work+0x144/0x390
[<
ffff0000080ec100>] worker_thread+0x144/0x418
[<
ffff0000080f2c98>] kthread+0x10c/0x138
[<
ffff0000080855dc>] ret_from_fork+0x10/0x18
If ata qc leaked too many, ata tag allocation will fail and io blocked
for ever.
As suggested by Dan Williams, defer ata device commands to libata and
merge sas_eh_finish_cmd() with sas_eh_defer_cmd(). libata will handle
ata qcs correctly after this.
Signed-off-by: Jason Yan <yanaijie@huawei.com>
CC: Xiaofei Tan <tanxiaofei@huawei.com>
CC: John Garry <john.garry@huawei.com>
CC: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Mark Salyzyn [Tue, 31 Jul 2018 22:02:13 +0000 (15:02 -0700)]
Bluetooth: hidp: buffer overflow in hidp_process_report
commit
7992c18810e568b95c869b227137a2215702a805 upstream.
CVE-2018-9363
The buffer length is unsigned at all layers, but gets cast to int and
checked in hidp_process_report and can lead to a buffer overflow.
Switch len parameter to unsigned int to resolve issue.
This affects 3.18 and newer kernels.
Signed-off-by: Mark Salyzyn <salyzyn@android.com>
Fixes: a4b1b5877b514b276f0f31efe02388a9c2836728 ("HID: Bluetooth: hidp: make sure input buffers are big enough")
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: linux-bluetooth@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: security@kernel.org
Cc: kernel-team@android.com
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Alexander Potapenko [Fri, 18 May 2018 14:23:18 +0000 (16:23 +0200)]
scsi: sg: allocate with __GFP_ZERO in sg_build_indirect()
commit
a45b599ad808c3c982fdcdc12b0b8611c2f92824 upstream.
This shall help avoid copying uninitialized memory to the userspace when
calling ioctl(fd, SG_IO) with an empty command.
Reported-by: syzbot+7d26fc1eea198488deab@syzkaller.appspotmail.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Shankara Pailoor [Tue, 5 Jun 2018 13:33:27 +0000 (08:33 -0500)]
jfs: Fix inconsistency between memory allocation and ea_buf->max_size
commit
92d34134193e5b129dc24f8d79cb9196626e8d7a upstream.
The code is assuming the buffer is max_size length, but we weren't
allocating enough space for it.
Signed-off-by: Shankara Pailoor <shankarapailoor@gmail.com>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Jens Axboe [Mon, 21 May 2018 18:21:14 +0000 (12:21 -0600)]
sr: pass down correctly sized SCSI sense buffer
commit
f7068114d45ec55996b9040e98111afa56e010fe upstream.
We're casting the CDROM layer request_sense to the SCSI sense
buffer, but the former is 64 bytes and the latter is 96 bytes.
As we generally allocate these on the stack, we end up blowing
up the stack.
Fix this by wrapping the scsi_execute() call with a properly
sized sense buffer, and copying back the bits for the CDROM
layer.
Reported-by: Piotr Gabriel Kosinski <pg.kosinski@gmail.com>
Reported-by: Daniel Shapira <daniel@twistlock.com>
Tested-by: Kees Cook <keescook@chromium.org>
Fixes: 82ed4db499b8 ("block: split scsi_request out of struct request")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
[bwh: Despite what the "Fixes" field says, a buffer overrun was already
possible if the sense data was really > 64 bytes long.
Backported to 3.16:
- We always need to allocate a sense buffer in order to call
scsi_normalize_sense()
- Remove the existing conditional heap-allocation of the sense buffer]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Paolo Bonzini [Wed, 6 Jun 2018 15:38:09 +0000 (17:38 +0200)]
kvm: x86: use correct privilege level for sgdt/sidt/fxsave/fxrstor access
commit
3c9fa24ca7c9c47605672916491f79e8ccacb9e6 upstream.
The functions that were used in the emulation of fxrstor, fxsave, sgdt and
sidt were originally meant for task switching, and as such they did not
check privilege levels. This is very bad when the same functions are used
in the emulation of unprivileged instructions. This is CVE-2018-10853.
The obvious fix is to add a new argument to ops->read_std and ops->write_std,
which decides whether the access is a "system" access or should use the
processor's CPL.
Fixes: 129a72a0d3c8 ("KVM: x86: Introduce segmented_write_std", 2017-01-12)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[bwh: Backported to 3.16: Drop change in handle_ud()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Paolo Bonzini [Wed, 6 Jun 2018 15:37:49 +0000 (17:37 +0200)]
KVM: x86: pass kvm_vcpu to kvm_read_guest_virt and kvm_write_guest_virt_system
commit
ce14e868a54edeb2e30cb7a7b104a2fc4b9d76ca upstream.
Int the next patch the emulator's .read_std and .write_std callbacks will
grow another argument, which is not needed in kvm_read_guest_virt and
kvm_write_guest_virt_system's callers. Since we have to make separate
functions, let's give the currently existing names a nicer interface, too.
Fixes: 129a72a0d3c8 ("KVM: x86: Introduce segmented_write_std", 2017-01-12)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[bwh: Backported to 3.16:
- Drop change to handle_invvpid()
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Paolo Bonzini [Wed, 6 Jun 2018 14:43:02 +0000 (16:43 +0200)]
KVM: x86: introduce linear_{read,write}_system
commit
79367a65743975e5cac8d24d08eccc7fdae832b0 upstream.
Wrap the common invocation of ctxt->ops->read_std and ctxt->ops->write_std, so
as to have a smaller patch when the functions grow another argument.
Fixes: 129a72a0d3c8 ("KVM: x86: Introduce segmented_write_std", 2017-01-12)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Nadav Amit [Mon, 2 Jun 2014 15:34:04 +0000 (18:34 +0300)]
KVM: x86: Emulator ignores LDTR/TR extended base on LLDT/LTR
commit
e37a75a13cdae5deaa2ea2cbf8d55b5dd08638b6 upstream.
The current implementation ignores the LDTR/TR base high 32-bits on long-mode.
As a result the loaded segment descriptor may be incorrect.
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Mel Gorman [Wed, 9 Aug 2017 07:27:11 +0000 (08:27 +0100)]
futex: Remove unnecessary warning from get_futex_key
commit
48fb6f4db940e92cfb16cd878cddd59ea6120d06 upstream.
Commit
65d8fc777f6d ("futex: Remove requirement for lock_page() in
get_futex_key()") removed an unnecessary lock_page() with the
side-effect that page->mapping needed to be treated very carefully.
Two defensive warnings were added in case any assumption was missed and
the first warning assumed a correct application would not alter a
mapping backing a futex key. Since merging, it has not triggered for
any unexpected case but Mark Rutland reported the following bug
triggering due to the first warning.
kernel BUG at kernel/futex.c:679!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 3695 Comm: syz-executor1 Not tainted
4.13.0-rc3-00020-g307fec773ba3 #3
Hardware name: linux,dummy-virt (DT)
task:
ffff80001e271780 task.stack:
ffff000010908000
PC is at get_futex_key+0x6a4/0xcf0 kernel/futex.c:679
LR is at get_futex_key+0x6a4/0xcf0 kernel/futex.c:679
pc : [<
ffff00000821ac14>] lr : [<
ffff00000821ac14>] pstate:
80000145
The fact that it's a bug instead of a warning was due to an unrelated
arm64 problem, but the warning itself triggered because the underlying
mapping changed.
This is an application issue but from a kernel perspective it's a
recoverable situation and the warning is unnecessary so this patch
removes the warning. The warning may potentially be triggered with the
following test program from Mark although it may be necessary to adjust
NR_FUTEX_THREADS to be a value smaller than the number of CPUs in the
system.
#include <linux/futex.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <unistd.h>
#define NR_FUTEX_THREADS 16
pthread_t threads[NR_FUTEX_THREADS];
void *mem;
#define MEM_PROT (PROT_READ | PROT_WRITE)
#define MEM_SIZE 65536
static int futex_wrapper(int *uaddr, int op, int val,
const struct timespec *timeout,
int *uaddr2, int val3)
{
syscall(SYS_futex, uaddr, op, val, timeout, uaddr2, val3);
}
void *poll_futex(void *unused)
{
for (;;) {
futex_wrapper(mem, FUTEX_CMP_REQUEUE_PI, 1, NULL, mem + 4, 1);
}
}
int main(int argc, char *argv[])
{
int i;
mem = mmap(NULL, MEM_SIZE, MEM_PROT,
MAP_SHARED | MAP_ANONYMOUS, -1, 0);
printf("Mapping @ %p\n", mem);
printf("Creating futex threads...\n");
for (i = 0; i < NR_FUTEX_THREADS; i++)
pthread_create(&threads[i], NULL, poll_futex, NULL);
printf("Flipping mapping...\n");
for (;;) {
mmap(mem, MEM_SIZE, MEM_PROT,
MAP_FIXED | MAP_SHARED | MAP_ANONYMOUS, -1, 0);
}
return 0;
}
Reported-and-tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Mel Gorman [Tue, 9 Feb 2016 19:15:14 +0000 (11:15 -0800)]
futex: Remove requirement for lock_page() in get_futex_key()
commit
65d8fc777f6dcfee12785c057a6b57f679641c90 upstream.
When dealing with key handling for shared futexes, we can drastically reduce
the usage/need of the page lock. 1) For anonymous pages, the associated futex
object is the mm_struct which does not require the page lock. 2) For inode
based, keys, we can check under RCU read lock if the page mapping is still
valid and take reference to the inode. This just leaves one rare race that
requires the page lock in the slow path when examining the swapcache.
Additionally realtime users currently have a problem with the page lock being
contended for unbounded periods of time during futex operations.
Task A
get_futex_key()
lock_page()
---> preempted
Now any other task trying to lock that page will have to wait until
task A gets scheduled back in, which is an unbound time.
With this patch, we pretty much have a lockless futex_get_key().
Experiments show that this patch can boost/speedup the hashing of shared
futexes with the perf futex benchmarks (which is good for measuring such
change) by up to 45% when there are high (> 100) thread counts on a 60 core
Westmere. Lower counts are pretty much in the noise range or less than 10%,
but mid range can be seen at over 30% overall throughput (hash ops/sec).
This makes anon-mem shared futexes much closer to its private counterpart.
Signed-off-by: Mel Gorman <mgorman@suse.de>
[ Ported on top of thp refcount rework, changelog, comments, fixes. ]
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Mason <clm@fb.com>
Cc: Darren Hart <dvhart@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: dave@stgolabs.net
Link: http://lkml.kernel.org/r/1455045314-8305-3-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Chenbo Feng <fengc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.16: s/READ_ONCE/ACCESS_ONCE/]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
projects / wrapfs-2.6.38.y.git / log