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

   1 From 307508d1072979f4435416f87936f87eaeb82054 Mon Sep 17 00:00:00 2001
   2 From: Eric Biggers <ebiggers@google.com>
   3 Date: Sun, 31 Mar 2019 13:04:12 -0700
   4 Subject: crypto: crct10dif-generic - fix use via crypto_shash_digest()
   5
   6 From: Eric Biggers <ebiggers@google.com>
   7
   8 commit 307508d1072979f4435416f87936f87eaeb82054 upstream.
   9
  10 The ->digest() method of crct10dif-generic 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 This bug was detected by my patches that improve testmgr to fuzz
  20 algorithms against their generic implementation.
  21
  22 Fixes: 2d31e518a428 ("crypto: crct10dif - Wrap crc_t10dif function all to use crypto transform framework")
  23 Cc: <stable@vger.kernel.org> # v3.11+
  24 Cc: Tim Chen <tim.c.chen@linux.intel.com>
  25 Signed-off-by: Eric Biggers <ebiggers@google.com>
  26 Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
  27 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  28
  29 ---
  30  crypto/crct10dif_generic.c |   11 ++++-------
  31  1 file changed, 4 insertions(+), 7 deletions(-)
  32
  33 --- a/crypto/crct10dif_generic.c
  34 +++ b/crypto/crct10dif_generic.c
  35 @@ -65,10 +65,9 @@ static int chksum_final(struct shash_des
  36         return 0;
  37  }
  38
  39 -static int __chksum_finup(__u16 *crcp, const u8 *data, unsigned int len,
  40 -                       u8 *out)
  41 +static int __chksum_finup(__u16 crc, const u8 *data, unsigned int len, u8 *out)
  42  {
  43 -       *(__u16 *)out = crc_t10dif_generic(*crcp, data, len);
  44 +       *(__u16 *)out = crc_t10dif_generic(crc, data, len);
  45         return 0;
  46  }
  47
  48 @@ -77,15 +76,13 @@ static int chksum_finup(struct shash_des
  49  {
  50         struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
  51
  52 -       return __chksum_finup(&ctx->crc, data, len, out);
  53 +       return __chksum_finup(ctx->crc, data, len, out);
  54  }
  55
  56  static int chksum_digest(struct shash_desc *desc, const u8 *data,
  57                          unsigned int length, u8 *out)
  58  {
  59 -       struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
  60 -
  61 -       return __chksum_finup(&ctx->crc, data, length, out);
  62 +       return __chksum_finup(0, data, length, out);
  63  }
  64
  65  static struct shash_alg alg = {