queue-4.19/kvm-svm-fix-potential-get_num_contig_pages-overflow.patch

   1 From ede885ecb2cdf8a8dd5367702e3d964ec846a2d5 Mon Sep 17 00:00:00 2001
   2 From: David Rientjes <rientjes@google.com>
   3 Date: Tue, 19 Mar 2019 15:19:56 -0700
   4 Subject: kvm: svm: fix potential get_num_contig_pages overflow
   5
   6 From: David Rientjes <rientjes@google.com>
   7
   8 commit ede885ecb2cdf8a8dd5367702e3d964ec846a2d5 upstream.
   9
  10 get_num_contig_pages() could potentially overflow int so make its type
  11 consistent with its usage.
  12
  13 Reported-by: Cfir Cohen <cfir@google.com>
  14 Cc: stable@vger.kernel.org
  15 Signed-off-by: David Rientjes <rientjes@google.com>
  16 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
  17 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  18
  19 ---
  20  arch/x86/kvm/svm.c |   10 +++++-----
  21  1 file changed, 5 insertions(+), 5 deletions(-)
  22
  23 --- a/arch/x86/kvm/svm.c
  24 +++ b/arch/x86/kvm/svm.c
  25 @@ -6398,11 +6398,11 @@ e_free:
  26         return ret;
  27  }
  28
  29 -static int get_num_contig_pages(int idx, struct page **inpages,
  30 -                               unsigned long npages)
  31 +static unsigned long get_num_contig_pages(unsigned long idx,
  32 +                               struct page **inpages, unsigned long npages)
  33  {
  34         unsigned long paddr, next_paddr;
  35 -       int i = idx + 1, pages = 1;
  36 +       unsigned long i = idx + 1, pages = 1;
  37
  38         /* find the number of contiguous pages starting from idx */
  39         paddr = __sme_page_pa(inpages[idx]);
  40 @@ -6421,12 +6421,12 @@ static int get_num_contig_pages(int idx,
  41
  42  static int sev_launch_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
  43  {
  44 -       unsigned long vaddr, vaddr_end, next_vaddr, npages, size;
  45 +       unsigned long vaddr, vaddr_end, next_vaddr, npages, pages, size, i;
  46         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
  47         struct kvm_sev_launch_update_data params;
  48         struct sev_data_launch_update_data *data;
  49         struct page **inpages;
  50 -       int i, ret, pages;
  51 +       int ret;
  52
  53         if (!sev_guest(kvm))
  54                 return -ENOTTY;