From: YOSHIFUJI Hideaki / 吉藤英明 <yoshfuji@linux-ipv6.org>
Date: Thu, 17 Jan 2013 12:53:02 +0000 (+0000)
Subject: ndisc: Update neigh->updated with write lock.
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=7ff74a596b6aa47ccc71f6b9a26006af69d0e33f;p=openwrt%2Fstaging%2Fblogic.git

ndisc: Update neigh->updated with write lock.

neigh->nud_state and neigh->updated are under protection of
neigh->lock.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 7c34c01b515b..1341f68e8009 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -499,22 +499,26 @@ static void rt6_probe(struct rt6_info *rt)
 	 * to no more than one per minute.
 	 */
 	neigh = rt ? rt->n : NULL;
-	if (!neigh || (neigh->nud_state & NUD_VALID))
+	if (!neigh)
+		return;
+	write_lock_bh(&neigh->lock);
+	if (neigh->nud_state & NUD_VALID) {
+		write_unlock_bh(&neigh->lock);
 		return;
-	read_lock_bh(&neigh->lock);
+	}
 	if (!(neigh->nud_state & NUD_VALID) &&
 	    time_after(jiffies, neigh->updated + rt->rt6i_idev->cnf.rtr_probe_interval)) {
 		struct in6_addr mcaddr;
 		struct in6_addr *target;
 
 		neigh->updated = jiffies;
-		read_unlock_bh(&neigh->lock);
+		write_unlock_bh(&neigh->lock);
 
 		target = (struct in6_addr *)&neigh->primary_key;
 		addrconf_addr_solict_mult(target, &mcaddr);
 		ndisc_send_ns(rt->dst.dev, NULL, target, &mcaddr, NULL);
 	} else {
-		read_unlock_bh(&neigh->lock);
+		write_unlock_bh(&neigh->lock);
 	}
 }
 #else