When using flowtable llentrys can outlive the interface with which they're associated

at which the lle_tbl pointer points to freed memory and the llt_free pointer is no longer
valid.

Move the free pointer in to the llentry itself and update the initalization sites.

MFC after:	2 weeks

sys/net/if_llatbl.h

@@ -106,7 +106,6 @@ struct llentry {
 		("negative refcnt %d", (lle)->lle_refcnt));	\
 	(lle)->lle_refcnt++;					\
 } while (0)
-
 #define	LLE_REMREF(lle)	do {					\
 	LLE_WLOCK_ASSERT(lle);					\
 	KASSERT((lle)->lle_refcnt > 1,				\
@@ -116,7 +115,7 @@ struct llentry {
 
 #define	LLE_FREE_LOCKED(lle) do {				\
 	if ((lle)->lle_refcnt <= 1)				\
-		(lle)->lle_tbl->llt_free((lle)->lle_tbl, (lle));\
+		(lle)->lle_free((lle)->lle_tbl, (lle));\
 	else {							\
 		(lle)->lle_refcnt--;				\
 		LLE_WUNLOCK(lle);				\
@@ -152,7 +151,6 @@ struct lltable {
 	int			llt_af;
 	struct ifnet		*llt_ifp;
 
-	void			(*llt_free)(struct lltable *, struct llentry *);
 	void			(*llt_prefix_free)(struct lltable *,
 				    const struct sockaddr *prefix,
 				    const struct sockaddr *mask,

sys/netinet/in.c

@@ -1260,6 +1260,20 @@ struct in_llentry {
 	struct sockaddr_in	l3_addr4;
 };
 
+/*
+ * Deletes an address from the address table.
+ * This function is called by the timer functions
+ * such as arptimer() and nd6_llinfo_timer(), and
+ * the caller does the locking.
+ */
+static void
+in_lltable_free(struct lltable *llt, struct llentry *lle)
+{
+	LLE_WUNLOCK(lle);
+	LLE_LOCK_DESTROY(lle);
+	free(lle, M_LLTABLE);
+}
+
 static struct llentry *
 in_lltable_new(const struct sockaddr *l3addr, u_int flags)
 {
@@ -1277,25 +1291,11 @@ in_lltable_new(const struct sockaddr *l3addr, u_int flags)
 	lle->base.la_expire = time_uptime; /* mark expired */
 	lle->l3_addr4 = *(const struct sockaddr_in *)l3addr;
 	lle->base.lle_refcnt = 1;
+	lle->base.lle_free = in_lltable_free;
 	LLE_LOCK_INIT(&lle->base);
 	return &lle->base;
 }
 
-/*
- * Deletes an address from the address table.
- * This function is called by the timer functions
- * such as arptimer() and nd6_llinfo_timer(), and
- * the caller does the locking.
- */
-static void
-in_lltable_free(struct lltable *llt, struct llentry *lle)
-{
-	LLE_WUNLOCK(lle);
-	LLE_LOCK_DESTROY(lle);
-	free(lle, M_LLTABLE);
-}
-
-
 #define IN_ARE_MASKED_ADDR_EQUAL(d, a, m)	(			\
 	    (((ntohl((d)->sin_addr.s_addr) ^ (a)->sin_addr.s_addr) & (m)->sin_addr.s_addr)) == 0 )
 
@@ -1577,7 +1577,6 @@ in_domifattach(struct ifnet *ifp)
 
 	llt = lltable_init(ifp, AF_INET);
 	if (llt != NULL) {
-		llt->llt_free = in_lltable_free;
 		llt->llt_prefix_free = in_lltable_prefix_free;
 		llt->llt_lookup = in_lltable_lookup;
 		llt->llt_dump = in_lltable_dump;

sys/netinet6/in6.c

@@ -2439,25 +2439,6 @@ struct in6_llentry {
 	struct sockaddr_in6	l3_addr6;
 };
 
-static struct llentry *
-in6_lltable_new(const struct sockaddr *l3addr, u_int flags)
-{
-	struct in6_llentry *lle;
-
-	lle = malloc(sizeof(struct in6_llentry), M_LLTABLE,
-	    M_DONTWAIT | M_ZERO);
-	if (lle == NULL)		/* NB: caller generates msg */
-		return NULL;
-
-	lle->l3_addr6 = *(const struct sockaddr_in6 *)l3addr;
-	lle->base.lle_refcnt = 1;
-	LLE_LOCK_INIT(&lle->base);
-	callout_init_rw(&lle->base.ln_timer_ch, &lle->base.lle_lock,
-	    CALLOUT_RETURNUNLOCKED);
-
-	return &lle->base;
-}
-
 /*
  * Deletes an address from the address table.
  * This function is called by the timer functions
@@ -2472,6 +2453,26 @@ in6_lltable_free(struct lltable *llt, struct llentry *lle)
 	free(lle, M_LLTABLE);
 }
 
+static struct llentry *
+in6_lltable_new(const struct sockaddr *l3addr, u_int flags)
+{
+	struct in6_llentry *lle;
+
+	lle = malloc(sizeof(struct in6_llentry), M_LLTABLE,
+	    M_DONTWAIT | M_ZERO);
+	if (lle == NULL)		/* NB: caller generates msg */
+		return NULL;
+
+	lle->l3_addr6 = *(const struct sockaddr_in6 *)l3addr;
+	lle->base.lle_refcnt = 1;
+	lle->base.lle_free = in6_lltable_free;
+	LLE_LOCK_INIT(&lle->base);
+	callout_init_rw(&lle->base.ln_timer_ch, &lle->base.lle_lock,
+	    CALLOUT_RETURNUNLOCKED);
+
+	return &lle->base;
+}
+
 static void
 in6_lltable_prefix_free(struct lltable *llt, 
 			const struct sockaddr *prefix,
@@ -2713,7 +2714,6 @@ in6_domifattach(struct ifnet *ifp)
 	ext->scope6_id = scope6_ifattach(ifp);
 	ext->lltable = lltable_init(ifp, AF_INET6);
 	if (ext->lltable != NULL) {
-		ext->lltable->llt_free = in6_lltable_free;
 		ext->lltable->llt_prefix_free = in6_lltable_prefix_free;
 		ext->lltable->llt_lookup = in6_lltable_lookup;
 		ext->lltable->llt_dump = in6_lltable_dump;