linux-crypto.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jeff Liu <jeff.liu@oracle.com>
To: linux-crypto@vger.kernel.org
Cc: herbert@gondor.hengli.com.au, davem@davemloft.net
Subject: [PATCH] crypto: fix potential NULL pointer dereference in skcipher_alloc_sgl()
Date: Fri, 15 Nov 2013 10:31:25 +0800	[thread overview]
Message-ID: <5285877D.7020004@oracle.com> (raw)

From: Jie Liu <jeff.liu@oracle.com>

In skcipher_alloc_sgl(), there is a potential null pointer dereference
issue to retrieve the last item from ctx->tsgl list if the list is empty.

This patch fix it by checking if the list is empty or not at first.

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
---
 crypto/algif_skcipher.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c
index a1c4f0a..bfa702e 100644
--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -73,9 +73,10 @@ static int skcipher_alloc_sgl(struct sock *sk)
 	struct skcipher_sg_list *sgl;
 	struct scatterlist *sg = NULL;
 
-	sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
-	if (!list_empty(&ctx->tsgl))
+	if (!list_empty(&ctx->tsgl)) {
+		sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
 		sg = sgl->sg;
+	}
 
 	if (!sg || sgl->cur >= MAX_SGL_ENTS) {
 		sgl = sock_kmalloc(sk, sizeof(*sgl) +
-- 
1.8.3.2

             reply	other threads:[~2013-11-15  2:31 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-11-15  2:31 Jeff Liu [this message]
2013-11-28 13:52 ` [PATCH] crypto: fix potential NULL pointer dereference in skcipher_alloc_sgl() Herbert Xu

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=5285877D.7020004@oracle.com \
    --to=jeff.liu@oracle.com \
    --cc=davem@davemloft.net \
    --cc=herbert@gondor.hengli.com.au \
    --cc=linux-crypto@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).