netdev - [PATCH][NETNS]: The ip6_fib_timer can work with garbage on net namespace stop.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 21 Apr 2008 17:05:50 +0400
From:	Pavel Emelyanov <xemul@...nvz.org>
To:	Linux Netdev List <netdev@...r.kernel.org>,
	David Miller <davem@...emloft.net>
Subject: [PATCH][NETNS]: The ip6_fib_timer can work with garbage on net namespace
 stop.

The del_timer() function doesn't guarantee, that the timer callback
is not active by the time it exits.

Thus, the fib6_net_exit() may kfree() all the data, that is required
by the fib6_run_gc(). The race window is tiny, but slab poisoning can
trigger this bug.

Using del_timer_sync() will cure this.

Signed-off-by: Pavel Emelyanov <xemul@...nvz.org>

---

diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 50f3f8f..1ee4fa1 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -1543,7 +1543,7 @@ out_timer:
 static void fib6_net_exit(struct net *net)
 {
 	rt6_ifdown(net, NULL);
-	del_timer(net->ipv6.ip6_fib_timer);
+	del_timer_sync(net->ipv6.ip6_fib_timer);
 	kfree(net->ipv6.ip6_fib_timer);
 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
 	kfree(net->ipv6.fib6_local_tbl);
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html