* [PATCH 4.14] crypto: arm64/aes-neonbs - don't access already-freed walk.iv
@ 2019-05-17 17:29 Eric Biggers
2019-05-18 6:58 ` Greg KH
0 siblings, 1 reply; 2+ messages in thread
From: Eric Biggers @ 2019-05-17 17:29 UTC (permalink / raw)
To: stable; +Cc: linux-crypto
From: Eric Biggers <ebiggers@google.com>
commit 4a8108b70508df0b6c4ffa4a3974dab93dcbe851 upstream.
[Please apply to 4.14-stable.]
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: 1abee99eafab ("crypto: arm64/aes - reimplement bit-sliced ARM/NEON implementation for arm64")
Cc: <stable@vger.kernel.org> # v4.11+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---
arch/arm64/crypto/aes-neonbs-glue.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/arm64/crypto/aes-neonbs-glue.c b/arch/arm64/crypto/aes-neonbs-glue.c
index c55d68ccb89f8..52975817fdb66 100644
--- a/arch/arm64/crypto/aes-neonbs-glue.c
+++ b/arch/arm64/crypto/aes-neonbs-glue.c
@@ -307,6 +307,8 @@ static int __xts_crypt(struct skcipher_request *req,
int err;
err = skcipher_walk_virt(&walk, req, true);
+ if (err)
+ return err;
kernel_neon_begin();
--
2.21.0.1020.gf2820cf01a-goog
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH 4.14] crypto: arm64/aes-neonbs - don't access already-freed walk.iv
2019-05-17 17:29 [PATCH 4.14] crypto: arm64/aes-neonbs - don't access already-freed walk.iv Eric Biggers
@ 2019-05-18 6:58 ` Greg KH
0 siblings, 0 replies; 2+ messages in thread
From: Greg KH @ 2019-05-18 6:58 UTC (permalink / raw)
To: Eric Biggers; +Cc: stable, linux-crypto
On Fri, May 17, 2019 at 10:29:51AM -0700, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
>
> commit 4a8108b70508df0b6c4ffa4a3974dab93dcbe851 upstream.
> [Please apply to 4.14-stable.]
Now applied, thanks.
greg k-h
^ permalink raw reply [flat|nested] 2+ messages in thread
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