queue-4.19/crypto-x86-crct10dif-pcl-fix-use-via-crypto_shash_digest.patch

   1 From dec3d0b1071a0f3194e66a83d26ecf4aa8c5910e Mon Sep 17 00:00:00 2001
   2 From: Eric Biggers <ebiggers@google.com>
   3 Date: Sun, 31 Mar 2019 13:04:13 -0700
   4 Subject: crypto: x86/crct10dif-pcl - fix use via crypto_shash_digest()
   5
   6 From: Eric Biggers <ebiggers@google.com>
   7
   8 commit dec3d0b1071a0f3194e66a83d26ecf4aa8c5910e upstream.
   9
  10 The ->digest() method of crct10dif-pclmul reads the current CRC value
  11 from the shash_desc context.  But this value is uninitialized, causing
  12 crypto_shash_digest() to compute the wrong result.  Fix it.
  13
  14 Probably this wasn't noticed before because lib/crc-t10dif.c only uses
  15 crypto_shash_update(), not crypto_shash_digest().  Likewise,
  16 crypto_shash_digest() is not yet tested by the crypto self-tests because
  17 those only test the ahash API which only uses shash init/update/final.
  18
  19 Fixes: 0b95a7f85718 ("crypto: crct10dif - Glue code to cast accelerated CRCT10DIF assembly as a crypto transform")
  20 Cc: <stable@vger.kernel.org> # v3.11+
  21 Cc: Tim Chen <tim.c.chen@linux.intel.com>
  22 Signed-off-by: Eric Biggers <ebiggers@google.com>
  23 Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
  24 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  25
  26 ---
  27  arch/x86/crypto/crct10dif-pclmul_glue.c |   13 +++++--------
  28  1 file changed, 5 insertions(+), 8 deletions(-)
  29
  30 --- a/arch/x86/crypto/crct10dif-pclmul_glue.c
  31 +++ b/arch/x86/crypto/crct10dif-pclmul_glue.c
  32 @@ -76,15 +76,14 @@ static int chksum_final(struct shash_des
  33         return 0;
  34  }
  35
  36 -static int __chksum_finup(__u16 *crcp, const u8 *data, unsigned int len,
  37 -                       u8 *out)
  38 +static int __chksum_finup(__u16 crc, const u8 *data, unsigned int len, u8 *out)
  39  {
  40         if (irq_fpu_usable()) {
  41                 kernel_fpu_begin();
  42 -               *(__u16 *)out = crc_t10dif_pcl(*crcp, data, len);
  43 +               *(__u16 *)out = crc_t10dif_pcl(crc, data, len);
  44                 kernel_fpu_end();
  45         } else
  46 -               *(__u16 *)out = crc_t10dif_generic(*crcp, data, len);
  47 +               *(__u16 *)out = crc_t10dif_generic(crc, data, len);
  48         return 0;
  49  }
  50
  51 @@ -93,15 +92,13 @@ static int chksum_finup(struct shash_des
  52  {
  53         struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
  54
  55 -       return __chksum_finup(&ctx->crc, data, len, out);
  56 +       return __chksum_finup(ctx->crc, data, len, out);
  57  }
  58
  59  static int chksum_digest(struct shash_desc *desc, const u8 *data,
  60                          unsigned int length, u8 *out)
  61  {
  62 -       struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
  63 -
  64 -       return __chksum_finup(&ctx->crc, data, length, out);
  65 +       return __chksum_finup(0, data, length, out);
  66  }
  67
  68  static struct shash_alg alg = {