From 0b3918fc435003b491155ca5418a9cdbedd15a92 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Thu, 27 Oct 2016 17:29:51 +0300 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") Cc: stable@vger.kernel.org Reported-by: xiakaixu Reported-by: Ard Biesheuvel Signed-off-by: Herbert Xu Tested-by: Ard Biesheuvel Signed-off-by: Andrey Ryabinin Signed-off-by: Willy Tarreau --- crypto/blkcipher.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/crypto/blkcipher.c b/crypto/blkcipher.c index 37af08e727c08..39b09f25e3f51 100644 --- a/crypto/blkcipher.c +++ b/crypto/blkcipher.c @@ -238,6 +238,8 @@ static int blkcipher_walk_next(struct blkcipher_desc *desc, return blkcipher_walk_done(desc, walk, -EINVAL); } + bsize = min(walk->blocksize, n); + walk->flags &= ~(BLKCIPHER_WALK_SLOW | BLKCIPHER_WALK_COPY | BLKCIPHER_WALK_DIFF); if (!scatterwalk_aligned(&walk->in, alignmask) || @@ -250,7 +252,6 @@ static int blkcipher_walk_next(struct blkcipher_desc *desc, } } - bsize = min(walk->blocksize, n); n = scatterwalk_clamp(&walk->in, n); n = scatterwalk_clamp(&walk->out, n); -- 2.47.2