This is a note to let you know that I've just added the patch titled crypto: skcipher - Fix crash on zero-length input to the 4.13-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-skcipher-fix-crash-on-zero-length-input.patch and it can be found in the queue-4.13 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 0cabf2af6f5ac3c88cb106c4e06087a5a39b8e1e Mon Sep 17 00:00:00 2001 From: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Date: Sat, 7 Oct 2017 11:29:48 +0800 Subject: crypto: skcipher - Fix crash on zero-length input MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> commit 0cabf2af6f5ac3c88cb106c4e06087a5a39b8e1e upstream. The skcipher walk interface doesn't handle zero-length input properly as the old blkcipher walk interface did. This is due to the fact that the length check is done too late. This patch moves the length check forward so that it does the right thing. Fixes: b286d8b1a690 ("crypto: skcipher - Add skcipher walk...") Reported-by: Stephan Müller <smueller@xxxxxxxxxx> Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- crypto/skcipher.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) --- a/crypto/skcipher.c +++ b/crypto/skcipher.c @@ -426,14 +426,9 @@ static int skcipher_copy_iv(struct skcip static int skcipher_walk_first(struct skcipher_walk *walk) { - walk->nbytes = 0; - if (WARN_ON_ONCE(in_irq())) return -EDEADLK; - if (unlikely(!walk->total)) - return 0; - walk->buffer = NULL; if (unlikely(((unsigned long)walk->iv & walk->alignmask))) { int err = skcipher_copy_iv(walk); @@ -452,10 +447,15 @@ static int skcipher_walk_skcipher(struct { struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + walk->total = req->cryptlen; + walk->nbytes = 0; + + if (unlikely(!walk->total)) + return 0; + scatterwalk_start(&walk->in, req->src); scatterwalk_start(&walk->out, req->dst); - walk->total = req->cryptlen; walk->iv = req->iv; walk->oiv = req->iv; @@ -509,6 +509,11 @@ static int skcipher_walk_aead_common(str struct crypto_aead *tfm = crypto_aead_reqtfm(req); int err; + walk->nbytes = 0; + + if (unlikely(!walk->total)) + return 0; + walk->flags &= ~SKCIPHER_WALK_PHYS; scatterwalk_start(&walk->in, req->src); Patches currently in stable-queue which might be from herbert@xxxxxxxxxxxxxxxxxxx are queue-4.13/crypto-skcipher-fix-crash-on-zero-length-input.patch queue-4.13/crypto-shash-fix-zero-length-shash-ahash-digest-crash.patch