| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.12 149/196] sunrpc: use constant time memory comparison for mac | Date | Tue, 25 Jul 2017 12:22:28 -0700 |
| |
4.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jason A. Donenfeld <Jason@zx2c4.com>
commit 15a8b93fd5690de017ce665382ea45e5d61811a4 upstream.
Otherwise, we enable a MAC forgery via timing attack.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Jeff Layton <jlayton@poochiereds.net> Cc: Trond Myklebust <trond.myklebust@primarydata.com> Cc: Anna Schumaker <anna.schumaker@netapp.com> Cc: linux-nfs@vger.kernel.org Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- net/sunrpc/auth_gss/gss_krb5_crypto.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- 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 *kc 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; }
|