Fix unexpected SA hard expiration after changing date

After SA is setup, one timer is armed to detect soft/hard expiration,
however the timer handler uses xtime to do the math. This makes hard
expiration occurs first before soft expiration after setting new date
with big interval. As a result new child SA is deleted before rekeying
the new one.

Signed-off-by: Fan Du <fdu@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 21 insertions, 4 deletions

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index d9509eb29b80..62b619e82a90 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -213,6 +213,9 @@ struct xfrm_state {
         struct xfrm_lifetime_cur curlft;
         struct tasklet_hrtimer  mtimer;
 
+        /* used to fix curlft->add_time when changing date */
+        long            saved_tmo;
+
         /* Last used time */
         unsigned long           lastused;
 
@@ -238,6 +241,7 @@ static inline struct net *xs_net(struct xfrm_state *x)
 
 /* xflags - make enum if more show up */
 #define XFRM_TIME_DEFER 1
+#define XFRM_SOFT_EXPIRE 2
 
 enum {
         XFRM_STATE_VOID,
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 5b228f97d4b3..87cd0e4d4282 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -415,8 +415,17 @@ static enum hrtimer_restart xfrm_timer_handler(struct hrtimer * me)
         if (x->lft.hard_add_expires_seconds) {
                 long tmo = x->lft.hard_add_expires_seconds +
                         x->curlft.add_time - now;
-                if (tmo <= 0)
-                        goto expired;
+                if (tmo <= 0) {
+                        if (x->xflags & XFRM_SOFT_EXPIRE) {
+                                /* enter hard expire without soft expire first?!
+                                 * setting a new date could trigger this.
+                                 * workarbound: fix x->curflt.add_time by below:
+                                 */
+                                x->curlft.add_time = now - x->saved_tmo - 1;
+                                tmo = x->lft.hard_add_expires_seconds - x->saved_tmo;
+                        } else
+                                goto expired;
+                }
                 if (tmo < next)
                         next = tmo;
         }
@@ -433,10 +442,14 @@ static enum hrtimer_restart xfrm_timer_handler(struct hrtimer * me)
         if (x->lft.soft_add_expires_seconds) {
                 long tmo = x->lft.soft_add_expires_seconds +
                         x->curlft.add_time - now;
-                if (tmo <= 0)
+                if (tmo <= 0) {
                         warn = 1;
-                else if (tmo < next)
+                        x->xflags &= ~XFRM_SOFT_EXPIRE;
+                } else if (tmo < next) {
                         next = tmo;
+                        x->xflags |= XFRM_SOFT_EXPIRE;
+                        x->saved_tmo = tmo;
+                }
         }
         if (x->lft.soft_use_expires_seconds) {
                 long tmo = x->lft.soft_use_expires_seconds +