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From: Stephen Hemminger <shemminger@vyatta.com>
To: "David S. Miller" <davem@davemloft.net>,
	Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: netdev@vger.kernel.org
Subject: [PATCH 02/12] IPv6: addrconf timer race
Date: Tue, 02 Mar 2010 15:32:45 -0800	[thread overview]
Message-ID: <20100302234002.971992509@vyatta.com> (raw)
In-Reply-To: 20100302233243.259794027@vyatta.com

[-- Attachment #1: addrconf-rstimer.patch --]
[-- Type: text/plain, Size: 1949 bytes --]

The Router Solicitation timer races with device state changes
because it doesn't lock the device. Use local variable to avoid
one repeated dereference.


Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>


--- a/net/ipv6/addrconf.c	2010-02-26 20:00:43.703982448 -0800
+++ b/net/ipv6/addrconf.c	2010-02-27 08:29:41.727984521 -0800
@@ -2739,28 +2739,29 @@ static int addrconf_ifdown(struct net_de
 static void addrconf_rs_timer(unsigned long data)
 {
 	struct inet6_ifaddr *ifp = (struct inet6_ifaddr *) data;
+	struct inet6_dev *idev = ifp->idev;
 
-	if (ifp->idev->cnf.forwarding)
+	read_lock(&idev->lock);
+	if (idev->dead || !(idev->if_flags & IF_READY))
 		goto out;
 
-	if (ifp->idev->if_flags & IF_RA_RCVD) {
-		/*
-		 *	Announcement received after solicitation
-		 *	was sent
-		 */
+	if (idev->cnf.forwarding)
+		goto out;
+
+	/* Announcement received after solicitation was sent */
+	if (idev->if_flags & IF_RA_RCVD)
 		goto out;
-	}
 
 	spin_lock(&ifp->lock);
-	if (ifp->probes++ < ifp->idev->cnf.rtr_solicits) {
+	if (ifp->probes++ < idev->cnf.rtr_solicits) {
 		/* The wait after the last probe can be shorter */
 		addrconf_mod_timer(ifp, AC_RS,
-				   (ifp->probes == ifp->idev->cnf.rtr_solicits) ?
-				   ifp->idev->cnf.rtr_solicit_delay :
-				   ifp->idev->cnf.rtr_solicit_interval);
+				   (ifp->probes == idev->cnf.rtr_solicits) ?
+				   idev->cnf.rtr_solicit_delay :
+				   idev->cnf.rtr_solicit_interval);
 		spin_unlock(&ifp->lock);
 
-		ndisc_send_rs(ifp->idev->dev, &ifp->addr, &in6addr_linklocal_allrouters);
+		ndisc_send_rs(idev->dev, &ifp->addr, &in6addr_linklocal_allrouters);
 	} else {
 		spin_unlock(&ifp->lock);
 		/*
@@ -2768,10 +2769,11 @@ static void addrconf_rs_timer(unsigned l
 		 * assumption any longer.
 		 */
 		printk(KERN_DEBUG "%s: no IPv6 routers present\n",
-		       ifp->idev->dev->name);
+		       idev->dev->name);
 	}
 
 out:
+	read_unlock(&idev->lock);
 	in6_ifa_put(ifp);
 }
 

-- 


  parent reply	other threads:[~2010-03-02 23:46 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-03-02 23:32 [PATCH 00/12] IPv6 addrconf changes Stephen Hemminger
2010-03-02 23:32 ` [PATCH 01/12] IPv6: addrconf dad timer unnecessary bh_disable Stephen Hemminger
2010-03-04  8:39   ` David Miller
2010-03-02 23:32 ` Stephen Hemminger [this message]
2010-03-04  8:40   ` [PATCH 02/12] IPv6: addrconf timer race David Miller
2010-03-02 23:32 ` [PATCH 03/12] IPv6: addrconf notify when address is unavailable Stephen Hemminger
2010-03-04  8:40   ` David Miller
2010-03-02 23:32 ` [PATCH 04/12] ipv6: convert temporary address list to list macros Stephen Hemminger
2010-03-02 23:32 ` [PATCH 05/12] ipv6: convert addrconf list to hlist Stephen Hemminger
2010-03-02 23:32 ` [PATCH 06/12] IPv6: convert addrconf hash list to RCU Stephen Hemminger
2010-03-02 23:32 ` [PATCH 07/12] ipv6: user better hash for addrconf Stephen Hemminger
2010-03-02 23:32 ` [PATCH 08/12] ipv6: convert idev_list to list macros Stephen Hemminger
2010-03-02 23:32 ` [PATCH 09/12] IPv6: addrconf cleanups Stephen Hemminger
2010-03-02 23:32 ` [PATCH 10/12] IPv6: addrconf checkpatch fixes Stephen Hemminger
2010-03-02 23:32 ` [PATCH 11/12] ipv6: addrconf timer changes Stephen Hemminger
2010-03-02 23:32 ` [PATCH 12/12] IPv6: addrconf cleanup addrconf_verify Stephen Hemminger
2010-03-03  9:16 ` [PATCH 00/12] IPv6 addrconf changes David Miller
2010-03-03 18:14   ` Stephen Hemminger
2010-03-03 18:19     ` [PATCH] IPv6: fix race between cleanup and add/delete address Stephen Hemminger
2010-03-04  8:40       ` David Miller

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