git.ipfire.org Git - thirdparty/kernel/stable-queue.git/blob

   1 From a788848116454d753b13a4888e0e31ada3c4d393 Mon Sep 17 00:00:00 2001
   2 From: Mikulas Patocka <mpatocka@redhat.com>
   3 Date: Wed, 5 Sep 2018 09:18:43 -0400
   4 Subject: crypto: aesni - don't use GFP_ATOMIC allocation if the request doesn't cross a page in gcm
   5
   6 From: Mikulas Patocka <mpatocka@redhat.com>
   7
   8 commit a788848116454d753b13a4888e0e31ada3c4d393 upstream.
   9
  10 This patch fixes gcmaes_crypt_by_sg so that it won't use memory
  11 allocation if the data doesn't cross a page boundary.
  12
  13 Authenticated encryption may be used by dm-crypt. If the encryption or
  14 decryption fails, it would result in I/O error and filesystem corruption.
  15 The function gcmaes_crypt_by_sg is using GFP_ATOMIC allocation that can
  16 fail anytime. This patch fixes the logic so that it won't attempt the
  17 failing allocation if the data doesn't cross a page boundary.
  18
  19 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
  20 Cc: stable@vger.kernel.org
  21 Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
  22 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  23
  24 ---
  25  arch/x86/crypto/aesni-intel_glue.c |    2 +-
  26  1 file changed, 1 insertion(+), 1 deletion(-)
  27
  28 --- a/arch/x86/crypto/aesni-intel_glue.c
  29 +++ b/arch/x86/crypto/aesni-intel_glue.c
  30 @@ -817,7 +817,7 @@ static int gcmaes_crypt_by_sg(bool enc,
  31         /* Linearize assoc, if not already linear */
  32         if (req->src->length >= assoclen && req->src->length &&
  33                 (!PageHighMem(sg_page(req->src)) ||
  34 -                       req->src->offset + req->src->length < PAGE_SIZE)) {
  35 +                       req->src->offset + req->src->length <= PAGE_SIZE)) {
  36                 scatterwalk_start(&assoc_sg_walk, req->src);
  37                 assoc = scatterwalk_map(&assoc_sg_walk);
  38         } else {