summary refs log tree commit diff
path: root/crypto/af_alg.c
diff options
context:
space:
mode:
authorEric Biggers <ebiggers@google.com>2017-11-28 00:46:24 -0800
committerHerbert Xu <herbert@gondor.apana.org.au>2017-11-29 13:39:14 +1100
commit887207ed9e5812ed9239b6d07185a2d35dda91db (patch)
treecadb413b15f8fd9699ad3f48638795a7bb9fb31e /crypto/af_alg.c
parentb32a7dc8aef1882fbf983eb354837488cc9d54dc (diff)
downloadlinux-887207ed9e5812ed9239b6d07185a2d35dda91db.tar.gz
crypto: af_alg - fix NULL pointer dereference in
 af_alg_free_areq_sgls()

If allocating the ->tsgl member of 'struct af_alg_async_req' failed,
during cleanup we dereferenced the NULL ->tsgl pointer in
af_alg_free_areq_sgls(), because ->tsgl_entries was nonzero.

Fix it by only freeing the ->tsgl list if it is non-NULL.

This affected both algif_skcipher and algif_aead.

Fixes: e870456d8e7c ("crypto: algif_skcipher - overhaul memory management")
Fixes: d887c52d6ae4 ("crypto: algif_aead - overhaul memory management")
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: <stable@vger.kernel.org> # v4.14+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto/af_alg.c')
-rw-r--r--crypto/af_alg.c13
1 files changed, 7 insertions, 6 deletions
diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index 85cea9de324a..1e5353f62067 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -672,14 +672,15 @@ void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
 	}
 
 	tsgl = areq->tsgl;
-	for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
-		if (!sg_page(sg))
-			continue;
-		put_page(sg_page(sg));
-	}
+	if (tsgl) {
+		for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
+			if (!sg_page(sg))
+				continue;
+			put_page(sg_page(sg));
+		}
 
-	if (areq->tsgl && areq->tsgl_entries)
 		sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
+	}
 }
 EXPORT_SYMBOL_GPL(af_alg_free_areq_sgls);