Commit 9b8adb5e authored May 13, 2009 by Eric W. Biederman Committed by David S. Miller May 18, 2009

net: Fix devinet_sysctl_forward



sysctls are unregistered with the rntl_lock held making
it unsafe to unconditionally grab the the rtnl_lock.  Instead
we need to call rtnl_trylock and restart the system call
if we can not grab it.  Otherwise we could deadlock at unregistration
time.

Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 5007392d

net/ipv4/devinet.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1347,7 +1347,8 @@ static int devinet_sysctl_forward(ctl_table *ctl, int write,
		struct net *net = ctl->extra2;

		if (valp != &IPV4_DEVCONF_DFLT(net, FORWARDING)) {
		rtnl_lock();
		if (!rtnl_trylock())
		return restart_syscall();
		if (valp == &IPV4_DEVCONF_ALL(net, FORWARDING)) {
		inet_forward_change(net);
		} else if (*valp) {