xfrm: Fix off by one in the replay advance functions

We may write 4 byte too much when we reinitialize the anti replay
window in the replay advance functions. This patch fixes this by
adjusting the last index of the initialization loop.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 2 deletions

diff --git a/net/xfrm/xfrm_replay.c b/net/xfrm/xfrm_replay.c
index 47f1b8638df9..b11ea692bd7d 100644
--- a/net/xfrm/xfrm_replay.c
+++ b/net/xfrm/xfrm_replay.c
@@ -265,7 +265,7 @@ static void xfrm_replay_advance_bmp(struct xfrm_state *x, __be32 net_seq)
                         bitnr = bitnr & 0x1F;
                         replay_esn->bmp[nr] |= (1U << bitnr);
                 } else {
-                        nr = replay_esn->replay_window >> 5;
+                        nr = (replay_esn->replay_window - 1) >> 5;
                         for (i = 0; i <= nr; i++)
                                 replay_esn->bmp[i] = 0;
 
@@ -471,7 +471,7 @@ static void xfrm_replay_advance_esn(struct xfrm_state *x, __be32 net_seq)
                         bitnr = bitnr & 0x1F;
                         replay_esn->bmp[nr] |= (1U << bitnr);
                 } else {
-                        nr = replay_esn->replay_window >> 5;
+                        nr = (replay_esn->replay_window - 1) >> 5;
                         for (i = 0; i <= nr; i++)
                                 replay_esn->bmp[i] = 0;