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()
6 From: Eric Biggers <ebiggers@google.com>
8 commit dec3d0b1071a0f3194e66a83d26ecf4aa8c5910e upstream.
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.
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.
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>
27 arch/x86/crypto/crct10dif-pclmul_glue.c | 13 +++++--------
28 1 file changed, 5 insertions(+), 8 deletions(-)
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
36 -static int __chksum_finup(__u16 *crcp, const u8 *data, unsigned int len,
38 +static int __chksum_finup(__u16 crc, const u8 *data, unsigned int len, u8 *out)
40 if (irq_fpu_usable()) {
42 - *(__u16 *)out = crc_t10dif_pcl(*crcp, data, len);
43 + *(__u16 *)out = crc_t10dif_pcl(crc, data, len);
46 - *(__u16 *)out = crc_t10dif_generic(*crcp, data, len);
47 + *(__u16 *)out = crc_t10dif_generic(crc, data, len);
51 @@ -93,15 +92,13 @@ static int chksum_finup(struct shash_des
53 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
55 - return __chksum_finup(&ctx->crc, data, len, out);
56 + return __chksum_finup(ctx->crc, data, len, out);
59 static int chksum_digest(struct shash_desc *desc, const u8 *data,
60 unsigned int length, u8 *out)
62 - struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
64 - return __chksum_finup(&ctx->crc, data, length, out);
65 + return __chksum_finup(0, data, length, out);
68 static struct shash_alg alg = {