Fix a deadlock with route change when the gateway address is non-local.

Ticket #6850 FreeBSD PR: 215122
pfsense · Dec 8, 2016 · 4627301 · 4627301
1 parent 4fb7ae5
commit 4627301
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Showing 4 changed files with 16 additions and 12 deletions.
diff --git a/sys/net/radix_mpath.c b/sys/net/radix_mpath.c
@@ -256,7 +256,7 @@ rtalloc_mpath_fib(struct route *ro, uint32_t hash, u_int fibnum)
 	if (ro->ro_rt && ro->ro_rt->rt_ifp && (ro->ro_rt->rt_flags & RTF_UP)
 	    && RT_LINK_IS_UP(ro->ro_rt->rt_ifp))
 		return;				 
-	ro->ro_rt = rtalloc1_fib(&ro->ro_dst, 1, 0, fibnum);
+	ro->ro_rt = rtalloc1_fib(&ro->ro_dst, 1, 0, fibnum, 0);
 
 	/* if the route does not exist or it is not multipath, don't care */
 	if (ro->ro_rt == NULL)

diff --git a/sys/net/route.c b/sys/net/route.c
@@ -417,7 +417,7 @@ rtalloc_ign_fib(struct route *ro, u_long ignore, u_int fibnum)
 		RTFREE(rt);
 		ro->ro_rt = NULL;
 	}
-	ro->ro_rt = rtalloc1_fib(&ro->ro_dst, 1, ignore, fibnum);
+	ro->ro_rt = rtalloc1_fib(&ro->ro_dst, 1, ignore, fibnum, 0);
 	if (ro->ro_rt)
 		RT_UNLOCK(ro->ro_rt);
 }
@@ -432,12 +432,12 @@ struct rtentry *
 rtalloc1(struct sockaddr *dst, int report, u_long ignflags)
 {
 
-	return (rtalloc1_fib(dst, report, ignflags, RT_DEFAULT_FIB));
+	return (rtalloc1_fib(dst, report, ignflags, RT_DEFAULT_FIB, 0));
 }
 
 struct rtentry *
-rtalloc1_fib(struct sockaddr *dst, int report, u_long ignflags,
-		    u_int fibnum)
+rtalloc1_fib(struct sockaddr *dst, int report, u_long ignflags, u_int fibnum,
+	u_int flags)
 {
 	struct rib_head *rh;
 	struct radix_node *rn;
@@ -454,16 +454,18 @@ rtalloc1_fib(struct sockaddr *dst, int report, u_long ignflags,
 	/*
 	 * Look up the address in the table for that Address Family
 	 */
-	RIB_RLOCK(rh);
+	if ((flags & RTF_RNH_LOCKED) == 0)
+		RIB_RLOCK(rh);
 	rn = rh->rnh_matchaddr(dst, &rh->head);
 	if (rn && ((rn->rn_flags & RNF_ROOT) == 0)) {
 		newrt = RNTORT(rn);
 		RT_LOCK(newrt);
 		RT_ADDREF(newrt);
-		RIB_RUNLOCK(rh);
+		if ((flags & RTF_RNH_LOCKED) == 0)
+			RIB_RUNLOCK(rh);
 		return (newrt);
 
-	} else
+	} else if ((flags & RTF_RNH_LOCKED) == 0)
 		RIB_RUNLOCK(rh);
 
 	/*
@@ -600,7 +602,7 @@ rtredirect_fib(struct sockaddr *dst,
 		error = ENETUNREACH;
 		goto out;
 	}
-	rt = rtalloc1_fib(dst, 0, 0UL, fibnum);	/* NB: rt is locked */
+	rt = rtalloc1_fib(dst, 0, 0UL, fibnum, 0);	/* NB: rt is locked */
 	/*
 	 * If the redirect isn't from our current router for this dst,
 	 * it's either old or wrong.  If it redirects us to ourselves,
@@ -749,7 +751,9 @@ ifa_ifwithroute(int flags, const struct sockaddr *dst, struct sockaddr *gateway,
 	if (ifa == NULL)
 		ifa = ifa_ifwithnet(gateway, 0, fibnum);
 	if (ifa == NULL) {
-		struct rtentry *rt = rtalloc1_fib(gateway, 0, 0, fibnum);
+		struct rtentry *rt;
+
+		rt = rtalloc1_fib(gateway, 0, 0, fibnum, RTF_RNH_LOCKED);
 		if (rt == NULL)
 			return (NULL);
 		/*

diff --git a/sys/net/route.h b/sys/net/route.h
@@ -482,7 +482,7 @@ int	 rtinit(struct ifaddr *, int, int);
  */
 int	 rt_getifa_fib(struct rt_addrinfo *, u_int fibnum);
 void	 rtalloc_ign_fib(struct route *ro, u_long ignflags, u_int fibnum);
-struct rtentry *rtalloc1_fib(struct sockaddr *, int, u_long, u_int);
+struct rtentry *rtalloc1_fib(struct sockaddr *, int, u_long, u_int, u_int);
 int	 rtioctl_fib(u_long, caddr_t, u_int);
 void	 rtredirect_fib(struct sockaddr *, struct sockaddr *,
 	    struct sockaddr *, int, struct sockaddr *, u_int);

diff --git a/sys/netinet6/in6_rmx.c b/sys/netinet6/in6_rmx.c
@@ -280,5 +280,5 @@ struct rtentry *
 in6_rtalloc1(struct sockaddr *dst, int report, u_long ignflags, u_int fibnum)
 {
 
-	return (rtalloc1_fib(dst, report, ignflags, fibnum));
+	return (rtalloc1_fib(dst, report, ignflags, fibnum, 0));
 }