From 9eb088e57edd9aa38e7d7a6c86424b4e6d5400eb Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Mon, 17 Jul 2017 15:32:30 +0800 Subject: [PATCH] crypto: authencesn - Fix digest_null crash 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. Fixes: 104880a6b470 ("crypto: authencesn - Convert to new AEAD...") Reported-by: Jan Tluka Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- crypto/authencesn.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/crypto/authencesn.c b/crypto/authencesn.c index 121010a..18c94e1 100644 --- a/crypto/authencesn.c +++ b/crypto/authencesn.c @@ -248,6 +248,9 @@ static int crypto_authenc_esn_decrypt_tail(struct aead_request *req, 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_tail(struct aead_request *req, if (crypto_memneq(ihash, ohash, authsize)) return -EBADMSG; +decrypt: + sg_init_table(areq_ctx->dst, 2); dst = scatterwalk_ffwd(areq_ctx->dst, dst, assoclen); -- 2.7.4