From b8273570f802a7658827dcb077b0b517ba75a289 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Thu, 24 Sep 2009 15:44:05 -0700 Subject: genetlink: fix netns vs. netlink table locking (2) Similar to commit d136f1bd366fdb7e747ca7e0218171e7a00a98a5, there's a bug when unregistering a generic netlink family, which is caught by the might_sleep() added in that commit: BUG: sleeping function called from invalid context at net/netlink/af_netlink.c:183 in_atomic(): 1, irqs_disabled(): 0, pid: 1510, name: rmmod 2 locks held by rmmod/1510: #0: (genl_mutex){+.+.+.}, at: [] genl_unregister_family+0x2b/0x130 #1: (rcu_read_lock){.+.+..}, at: [] __genl_unregister_mc_group+0x1c/0x120 Pid: 1510, comm: rmmod Not tainted 2.6.31-wl #444 Call Trace: [] __might_sleep+0x119/0x150 [] netlink_table_grab+0x21/0x100 [] netlink_clear_multicast_users+0x23/0x60 [] __genl_unregister_mc_group+0x71/0x120 [] genl_unregister_family+0x56/0x130 [] nl80211_exit+0x15/0x20 [cfg80211] [] cfg80211_exit+0x1a/0x40 [cfg80211] Fix in the same way by grabbing the netlink table lock before doing rcu_read_lock(). Signed-off-by: Johannes Berg Signed-off-by: David S. Miller --- include/linux/netlink.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/netlink.h') diff --git a/include/linux/netlink.h b/include/linux/netlink.h index 080f6ba9e73a..ab5d3126831f 100644 --- a/include/linux/netlink.h +++ b/include/linux/netlink.h @@ -187,6 +187,7 @@ extern struct sock *netlink_kernel_create(struct net *net, extern void netlink_kernel_release(struct sock *sk); extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups); extern int netlink_change_ngroups(struct sock *sk, unsigned int groups); +extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group); extern void netlink_clear_multicast_users(struct sock *sk, unsigned int group); extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err); extern int netlink_has_listeners(struct sock *sk, unsigned int group); -- cgit v1.2.3