lkml.org 
[lkml]   [2019]   [Mar]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 5.0 022/238] crypto: ahash - fix another early termination in hash walk
Date
5.0-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Eric Biggers <ebiggers@google.com>

commit 77568e535af7c4f97eaef1e555bf0af83772456c upstream.

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>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
crypto/ahash.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

--- a/crypto/ahash.c
+++ b/crypto/ahash.c
@@ -86,17 +86,17 @@ static int hash_walk_new_entry(struct cr
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_
if (err)
return err;

- if (nbytes) {
+ if (walk->entrylen) {
walk->offset = 0;
walk->pg++;
return hash_walk_next(walk);

\
 
 \ /
  Last update: 2019-03-22 13:14    [W:0.531 / U:1.552 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site