[PATCH 3.16 085/306] crypto: gcm - Fix IV buffer size in crypto_gcm_setkey

From: Ben Hutchings
Date: Wed Feb 15 2017 - 18:17:23 EST

3.16.40-rc1 review patch. If anyone has any objections, please let me know.


From: Ondrej MosnÃÄek <omosnacek@xxxxxxxxx>

commit 50d2e6dc1f83db0563c7d6603967bf9585ce934b upstream.

The cipher block size for GCM is 16 bytes, and thus the CTR transform
used in crypto_gcm_setkey() will also expect a 16-byte IV. However,
the code currently reserves only 8 bytes for the IV, causing
an out-of-bounds access in the CTR transform. This patch fixes
the issue by setting the size of the IV buffer to 16 bytes.

Fixes: 84c911523020 ("[CRYPTO] gcm: Add support for async ciphers")
Signed-off-by: Ondrej Mosnacek <omosnacek@xxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
crypto/gcm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/crypto/gcm.c
+++ b/crypto/gcm.c
@@ -109,7 +109,7 @@ static int crypto_gcm_setkey(struct cryp
struct crypto_ablkcipher *ctr = ctx->ctr;
struct {
be128 hash;
- u8 iv[8];
+ u8 iv[16];

struct crypto_gcm_setkey_result result;