From: Kefeng Wang Date: Thu, 19 Jan 2017 08:26:21 +0000 (+0800) Subject: ipv6: addrconf: Avoid addrconf_disable_change() using RCU read-side lock X-Git-Tag: v3.12.71~96 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1065fdb1dba37d36587ad22daa2e841e357eaf5f;p=thirdparty%2Fkernel%2Fstable.git ipv6: addrconf: Avoid addrconf_disable_change() using RCU read-side lock [ Upstream commit 03e4deff4987f79c34112c5ba4eb195d4f9382b0 ] Just like commit 4acd4945cd1e ("ipv6: addrconf: Avoid calling netdevice notifiers with RCU read-side lock"), it is unnecessary to make addrconf_disable_change() use RCU iteration over the netdev list, since it already holds the RTNL lock, or we may meet Illegal context switch in RCU read-side critical section. Signed-off-by: Kefeng Wang Signed-off-by: David S. Miller Signed-off-by: Jiri Slaby --- diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 1e31fc5477e8b..74fe3375aa7a5 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -4693,8 +4693,7 @@ static void addrconf_disable_change(struct net *net, __s32 newf) struct net_device *dev; struct inet6_dev *idev; - rcu_read_lock(); - for_each_netdev_rcu(net, dev) { + for_each_netdev(net, dev) { idev = __in6_dev_get(dev); if (idev) { int changed = (!idev->cnf.disable_ipv6) ^ (!newf); @@ -4703,7 +4702,6 @@ static void addrconf_disable_change(struct net *net, __s32 newf) dev_disable_change(idev); } } - rcu_read_unlock(); } static int addrconf_disable_ipv6(struct ctl_table *table, int *p, int newf)