This is a note to let you know that I've just added the patch titled
crypto: shash - Fix zero-length shash ahash digest crash
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
crypto-shash-fix-zero-length-shash-ahash-digest-crash.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From b61907bb42409adf9b3120f741af7c57dd7e3db2 Mon Sep 17 00:00:00 2001
From: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Date: Mon, 9 Oct 2017 23:30:02 +0800
Subject: crypto: shash - Fix zero-length shash ahash digest crash
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From: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
commit b61907bb42409adf9b3120f741af7c57dd7e3db2 upstream.
The shash ahash digest adaptor function may crash if given a
zero-length input together with a null SG list. This is because
it tries to read the SG list before looking at the length.
This patch fixes it by checking the length first.
Reported-by: Stephan Müller<smueller@xxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Tested-by: Stephan Müller <smueller@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
crypto/shash.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
--- a/crypto/shash.c
+++ b/crypto/shash.c
@@ -274,12 +274,14 @@ static int shash_async_finup(struct ahas
int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
{
- struct scatterlist *sg = req->src;
- unsigned int offset = sg->offset;
unsigned int nbytes = req->nbytes;
+ struct scatterlist *sg;
+ unsigned int offset;
int err;
- if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
+ if (nbytes &&
+ (sg = req->src, offset = sg->offset,
+ nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset))) {
void *data;
data = kmap_atomic(sg_page(sg));
Patches currently in stable-queue which might be from herbert@xxxxxxxxxxxxxxxxxxx are
queue-4.9/crypto-shash-fix-zero-length-shash-ahash-digest-crash.patch