kvm: svm: fix potential get_num_contig_pages overflow

commit ede885ecb2cdf8a8dd5367702e3d964ec846a2d5 upstream.

get_num_contig_pages() could potentially overflow int so make its type
consistent with its usage.

Reported-by: Cfir Cohen <cfir@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index b475419620121609ae7de1db923385f6674f8ead..6dc72804fe6ed3e9c717fb2e602e0130dd0ae833 100644 (file)
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -6398,11 +6398,11 @@ e_free:
        return ret;
 }
 
-static int get_num_contig_pages(int idx, struct page **inpages,
-                               unsigned long npages)
+static unsigned long get_num_contig_pages(unsigned long idx,
+                               struct page **inpages, unsigned long npages)
 {
        unsigned long paddr, next_paddr;
-       int i = idx + 1, pages = 1;
+       unsigned long i = idx + 1, pages = 1;
 
        /* find the number of contiguous pages starting from idx */
        paddr = __sme_page_pa(inpages[idx]);
@@ -6421,12 +6421,12 @@ static int get_num_contig_pages(int idx, struct page **inpages,
 
 static int sev_launch_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
-       unsigned long vaddr, vaddr_end, next_vaddr, npages, size;
+       unsigned long vaddr, vaddr_end, next_vaddr, npages, pages, size, i;
        struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
        struct kvm_sev_launch_update_data params;
        struct sev_data_launch_update_data *data;
        struct page **inpages;
-       int i, ret, pages;
+       int ret;
 
        if (!sev_guest(kvm))
                return -ENOTTY;