Commit 4a8108b7 authored by Eric Biggers's avatar Eric Biggers Committed by Herbert Xu

crypto: arm64/aes-neonbs - don't access already-freed walk.iv

If the user-provided IV needs to be aligned to the algorithm's
alignmask, then skcipher_walk_virt() copies the IV into a new aligned
buffer walk.iv.  But skcipher_walk_virt() can fail afterwards, and then
if the caller unconditionally accesses walk.iv, it's a use-after-free.

xts-aes-neonbs doesn't set an alignmask, so currently it isn't affected
by this despite unconditionally accessing walk.iv.  However this is more
subtle than desired, and unconditionally accessing walk.iv has caused a
real problem in other algorithms.  Thus, update xts-aes-neonbs to start
checking the return value of skcipher_walk_virt().

Fixes: 1abee99e ("crypto: arm64/aes - reimplement bit-sliced ARM/NEON implementation for arm64")
Cc: <stable@vger.kernel.org> # v4.11+
Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 767f015e
......@@ -304,6 +304,8 @@ static int __xts_crypt(struct skcipher_request *req,
int err;
err = skcipher_walk_virt(&walk, req, false);
if (err)
return err;
kernel_neon_begin();
neon_aes_ecb_encrypt(walk.iv, walk.iv, ctx->twkey, ctx->key.rounds, 1);
......
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