Patch "crypto: authencesn - Fix digest_null crash" has been added to the 4.9-stable tree

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

crypto: authencesn - Fix digest_null 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-authencesn-fix-digest_null-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 <[email protected]> know about it.

From: Herbert Xu <[email protected]>
Date: Mon, 17 Jul 2017 15:32:30 +0800
Subject: crypto: authencesn - Fix digest_null crash

From: Herbert Xu <[email protected]>

commit 41cdf7a45389e01991ee31e3301ed83cb3e3f7dc upstream.

When authencesn is used together with digest_null a crash will occur on the decrypt path. This is because normally we perform a special setup to preserve the ESN, but this is skipped if there is no authentication. However, on the post-authentication path it always expects the preservation to be in place, thus causing a crash when digest_null is used.

This patch fixes this by also skipping the post-processing when there is no authentication.

---
 crypto/authencesn.c |    5 +++++
 1 file changed, 5 insertions(+)

@@ -248,6 +248,9 @@ static int crypto_authenc_esn_decrypt_ta
 	u8 *ihash = ohash + crypto_ahash_digestsize(auth);
 	u32 tmp[2];
 
+	if (!authsize)
+		goto decrypt;
+
 	/* Move high-order bits of sequence number back. */
 	scatterwalk_map_and_copy(tmp, dst, 4, 4, 0);
 	scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 0);

@@ -256,6 +259,8 @@ static int crypto_authenc_esn_decrypt_ta
 	if (crypto_memneq(ihash, ohash, authsize))
 		return -EBADMSG;
 
+decrypt:
+
 	sg_init_table(areq_ctx->dst, 2);
 	dst = scatterwalk_ffwd(areq_ctx->dst, dst, assoclen);
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/crypto-authencesn-fix-digest_null-crash.patch