ACPI: fix NULL pointer dereference
authorLinus Torvalds <torvalds@linux-foundation.org>
Sat, 24 Jul 2021 22:25:54 +0000 (15:25 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 8 Aug 2021 07:05:23 +0000 (09:05 +0200)
commitcae3fa3d8165761f3000f523b11cfa1cd35206bc
tree2d8e633669a0935371724dd5e72cef045ab48bdc
parent98b070694f4570908a0e8ea5afb68d81b0aa2051
ACPI: fix NULL pointer dereference

[ Upstream commit fc68f42aa737dc15e7665a4101d4168aadb8e4c4 ]

Commit 71f642833284 ("ACPI: utils: Fix reference counting in
for_each_acpi_dev_match()") started doing "acpi_dev_put()" on a pointer
that was possibly NULL.  That fails miserably, because that helper
inline function is not set up to handle that case.

Just make acpi_dev_put() silently accept a NULL pointer, rather than
calling down to put_device() with an invalid offset off that NULL
pointer.

Link: https://lore.kernel.org/lkml/a607c149-6bf6-0fd0-0e31-100378504da2@kernel.dk/
Reported-and-tested-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Daniel Scally <djrscally@gmail.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
include/acpi/acpi_bus.h