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,
"Jason A . Donenfeld" <Jason@zx2c4.com>,
stable@vger.kernel.org
Subject: [RFC/RFT PATCH 06/15] crypto: ahash - fix another early termination in hash walk
Date: Wed, 23 Jan 2019 14:49:17 -0800 [thread overview]
Message-ID: <20190123224926.250525-7-ebiggers@kernel.org> (raw)
In-Reply-To: <20190123224926.250525-1-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 ca0d3e281fef..81e2767e2164 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);
--
2.20.1.321.g9e740568ce-goog
next prev parent reply other threads:[~2019-01-23 22:54 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190123224926.250525-1-ebiggers@kernel.org>
2019-01-23 22:49 ` [RFC/RFT PATCH 01/15] crypto: aegis - fix handling chunked inputs Eric Biggers
2019-01-23 22:49 ` [RFC/RFT PATCH 02/15] crypto: morus " Eric Biggers
2019-01-31 9:05 ` Ondrej Mosnacek
2019-02-01 5:25 ` Eric Biggers
2019-01-23 22:49 ` [RFC/RFT PATCH 03/15] crypto: x86/aegis - fix handling chunked inputs and MAY_SLEEP Eric Biggers
2019-01-23 22:49 ` [RFC/RFT PATCH 04/15] crypto: x86/morus " Eric Biggers
2019-01-23 22:49 ` [RFC/RFT PATCH 05/15] crypto: x86/aesni-gcm - fix crash on empty plaintext Eric Biggers
2019-01-23 22:49 ` Eric Biggers [this message]
2019-01-23 22:49 ` [RFC/RFT PATCH 07/15] crypto: arm64/aes-neonbs - fix returning final keystream block Eric Biggers
2019-01-24 12:11 ` Ard Biesheuvel
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