Patch "crypto: af_alg - fix NULL pointer dereference in" has been added to the 4.14-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    crypto: af_alg - fix NULL pointer dereference in

to the 4.14-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-af_alg-fix-null-pointer-dereference-in.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 887207ed9e5812ed9239b6d07185a2d35dda91db Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers@google.com>
Date: Tue, 28 Nov 2017 00:46:24 -0800
Subject: crypto: af_alg - fix NULL pointer dereference in

From: Eric Biggers <ebiggers@google.com>

commit 887207ed9e5812ed9239b6d07185a2d35dda91db upstream.

 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>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 crypto/af_alg.c |   13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -699,14 +699,15 @@ void af_alg_free_areq_sgls(struct af_alg
 	}
 
 	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);
 


Patches currently in stable-queue which might be from ebiggers@google.com are

queue-4.14/crypto-algif_aead-fix-reference-counting-of-null-skcipher.patch
queue-4.14/crypto-salsa20-fix-blkcipher_walk-api-usage.patch
queue-4.14/crypto-rsa-fix-buffer-overread-when-stripping-leading-zeroes.patch
queue-4.14/crypto-hmac-require-that-the-underlying-hash-algorithm-is-unkeyed.patch
queue-4.14/crypto-af_alg-fix-null-pointer-dereference-in.patch