From 1c95a8a481efa5716b847b75f9c8b26f65844362 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: Greg Kroah-Hartman --- crypto/blkcipher.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/crypto/blkcipher.c b/crypto/blkcipher.c index 8cc1622..dca7bc8 100644 --- a/crypto/blkcipher.c +++ b/crypto/blkcipher.c @@ -234,6 +234,8 @@ 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) || @@ -246,7 +248,6 @@ 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); -- 2.7.4