From c5ffd6085701f2664b030aecd49a8488bef3bc84 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Tue, 13 Sep 2016 14:43:29 +0800 Subject: [PATCH] crypto: skcipher - Fix blkcipher walk OOM crash commit acdb04d0b36769b3e05990c488dc74d8b7ac8060 upstream. When we need to allocate a temporary blkcipher_walk_next and it fails, the code is supposed to take the slow path of processing the data block by block. However, due to an unrelated change we instead end up dereferencing the NULL pointer. This patch fixes it by moving the unrelated bsize setting out of the way so that we enter the slow path as inteded. Fixes: 7607bd8ff03b ("[CRYPTO] blkcipher: Added blkcipher_walk_virt_block") Reported-by: xiakaixu Reported-by: Ard Biesheuvel Signed-off-by: Herbert Xu Tested-by: Ard Biesheuvel Signed-off-by: Ben Hutchings --- crypto/blkcipher.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/crypto/blkcipher.c b/crypto/blkcipher.c index 3c551d46aa3b2..37130b81d0d44 100644 --- a/crypto/blkcipher.c +++ b/crypto/blkcipher.c @@ -233,6 +233,8 @@ static int blkcipher_walk_next(struct blkcipher_desc *desc, return blkcipher_walk_done(desc, walk, -EINVAL); } + bsize = min(walk->walk_blocksize, n); + walk->flags &= ~(BLKCIPHER_WALK_SLOW | BLKCIPHER_WALK_COPY | BLKCIPHER_WALK_DIFF); if (!scatterwalk_aligned(&walk->in, walk->alignmask) || @@ -245,7 +247,6 @@ static int blkcipher_walk_next(struct blkcipher_desc *desc, } } - bsize = min(walk->walk_blocksize, n); n = scatterwalk_clamp(&walk->in, n); n = scatterwalk_clamp(&walk->out, n); -- 2.47.3