tree 0c9d197927599fe8a5e398dca1ab4f33a1ec108b
parent 91078439cc1c5c2f061cf7bac465ccf203933e84
author Eric Biggers <ebiggers@google.com> 1554878791 -0700
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1558457340 +0200

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

commit 767f015ea0b7ab9d60432ff6cd06b664fd71f50f upstream.

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.

arm32 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 it was actually broken prior to
the alignmask being removed by commit cc477bf64573 ("crypto: arm/aes -
replace bit-sliced OpenSSL NEON code").  Thus, update xts-aes-neonbs to
start checking the return value of skcipher_walk_virt().

Fixes: e4e7f10bfc40 ("ARM: add support for bit sliced AES using NEON instructions")
Cc: <stable@vger.kernel.org> # v3.13+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>