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From: Eric Biggers <ebiggers@kernel.org>
To: linux-crypto@vger.kernel.org, Herbert Xu <herbert@gondor.apana.org.au>
Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Subject: [PATCH v2 06/15] crypto: ahash - fix another early termination in hash walk
Date: Thu, 31 Jan 2019 23:51:41 -0800	[thread overview]
Message-ID: <20190201075150.18644-7-ebiggers@kernel.org> (raw)
In-Reply-To: <20190201075150.18644-1-ebiggers@kernel.org>

From: Eric Biggers <ebiggers@google.com>

Hash algorithms with an alignmask set, e.g. "xcbc(aes-aesni)" and
"michael_mic", fail the improved hash tests because they sometimes
produce the wrong digest.  The bug is that in the case where a
scatterlist element crosses pages, not all the data is actually hashed
because the scatterlist walk terminates too early.  This happens because
the 'nbytes' variable in crypto_hash_walk_done() is assigned the number
of bytes remaining in the page, then later interpreted as the number of
bytes remaining in the scatterlist element.  Fix it.

Fixes: 900a081f6912 ("crypto: ahash - Fix early termination in hash walk")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 crypto/ahash.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/crypto/ahash.c b/crypto/ahash.c
index ca0d3e281fefb..81e2767e2164e 100644
--- a/crypto/ahash.c
+++ b/crypto/ahash.c
@@ -86,17 +86,17 @@ static int hash_walk_new_entry(struct crypto_hash_walk *walk)
 int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
 {
 	unsigned int alignmask = walk->alignmask;
-	unsigned int nbytes = walk->entrylen;
 
 	walk->data -= walk->offset;
 
-	if (nbytes && walk->offset & alignmask && !err) {
-		walk->offset = ALIGN(walk->offset, alignmask + 1);
-		nbytes = min(nbytes,
-			     ((unsigned int)(PAGE_SIZE)) - walk->offset);
-		walk->entrylen -= nbytes;
+	if (walk->entrylen && (walk->offset & alignmask) && !err) {
+		unsigned int nbytes;
 
+		walk->offset = ALIGN(walk->offset, alignmask + 1);
+		nbytes = min(walk->entrylen,
+			     (unsigned int)(PAGE_SIZE - walk->offset));
 		if (nbytes) {
+			walk->entrylen -= nbytes;
 			walk->data += walk->offset;
 			return nbytes;
 		}
@@ -116,7 +116,7 @@ int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
 	if (err)
 		return err;
 
-	if (nbytes) {
+	if (walk->entrylen) {
 		walk->offset = 0;
 		walk->pg++;
 		return hash_walk_next(walk);
-- 
2.20.1


  parent reply	other threads:[~2019-02-01  7:53 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-01  7:51 [PATCH v2 00/15] crypto: improved skcipher, aead, and hash tests Eric Biggers
2019-02-01  7:51 ` [PATCH v2 01/15] crypto: aegis - fix handling chunked inputs Eric Biggers
2019-02-05  9:31   ` Ondrej Mosnacek
2019-02-01  7:51 ` [PATCH v2 02/15] crypto: morus " Eric Biggers
2019-02-05  9:30   ` Ondrej Mosnacek
2019-02-01  7:51 ` [PATCH v2 03/15] crypto: x86/aegis - fix handling chunked inputs and MAY_SLEEP Eric Biggers
2019-02-05  9:31   ` Ondrej Mosnacek
2019-02-01  7:51 ` [PATCH v2 04/15] crypto: x86/morus " Eric Biggers
2019-02-05  9:32   ` Ondrej Mosnacek
2019-02-01  7:51 ` [PATCH v2 05/15] crypto: x86/aesni-gcm - fix crash on empty plaintext Eric Biggers
2019-02-01  7:51 ` Eric Biggers [this message]
2019-02-01  7:51 ` [PATCH v2 07/15] crypto: arm64/aes-neonbs - fix returning final keystream block Eric Biggers
2019-02-01  7:51 ` [PATCH v2 08/15] crypto: testmgr - add testvec_config struct and helper functions Eric Biggers
2019-02-01  7:51 ` [PATCH v2 09/15] crypto: testmgr - introduce CONFIG_CRYPTO_MANAGER_EXTRA_TESTS Eric Biggers
2019-02-01  7:51 ` [PATCH v2 10/15] crypto: testmgr - implement random testvec_config generation Eric Biggers
2019-02-01  7:51 ` [PATCH v2 11/15] crypto: testmgr - convert skcipher testing to use testvec_configs Eric Biggers
2019-02-01  7:51 ` [PATCH v2 12/15] crypto: testmgr - convert aead " Eric Biggers
2019-02-01  7:51 ` [PATCH v2 13/15] crypto: testmgr - convert hash " Eric Biggers
2019-08-29 15:32   ` Christophe Leroy
2019-08-29 15:58     ` Eric Biggers
2019-02-01  7:51 ` [PATCH v2 14/15] crypto: testmgr - check for skcipher_request corruption Eric Biggers
2019-02-01  7:51 ` [PATCH v2 15/15] crypto: testmgr - check for aead_request corruption Eric Biggers
2019-02-08  7:47 ` [PATCH v2 00/15] crypto: improved skcipher, aead, and hash tests Herbert Xu

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