Otherwise, we enable a MAC forgery via timing attack.
Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
Cc: "J. Bruce Fields" <bfields@xxxxxxxxxxxx>
Cc: Jeff Layton <jlayton@xxxxxxxxxxxxxxx>
Cc: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Cc: Anna Schumaker <anna.schumaker@xxxxxxxxxx>
Cc: linux-nfs@xxxxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
---
net/sunrpc/auth_gss/gss_krb5_crypto.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/sunrpc/auth_gss/gss_krb5_crypto.c b/net/sunrpc/auth_gss/gss_krb5_crypto.c
index fb39284ec174..12649c9fedab 100644
--- a/net/sunrpc/auth_gss/gss_krb5_crypto.c
+++ b/net/sunrpc/auth_gss/gss_krb5_crypto.c
@@ -34,6 +34,7 @@
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
+#include <crypto/algapi.h>
#include <crypto/hash.h>
#include <crypto/skcipher.h>
#include <linux/err.h>
@@ -927,7 +928,7 @@ gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset, struct xdr_buf *buf,
if (ret)
goto out_err;
- if (memcmp(pkt_hmac, our_hmac, kctx->gk5e->cksumlength) != 0) {
+ if (crypto_memneq(pkt_hmac, our_hmac, kctx->gk5e->cksumlength) != 0) {
ret = GSS_S_BAD_SIG;
goto out_err;
}
--
2.13.1