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authorJohannes Berg <johannes@sipsolutions.net>2009-09-24 15:44:05 -0700
committerDavid S. Miller <davem@davemloft.net>2009-09-24 15:44:05 -0700
commitb8273570f802a7658827dcb077b0b517ba75a289 (patch)
tree06fcee4433089cdb16504f40b1975ebbdf69e241 /net/netlink/genetlink.c
parent704cc92e9ffe29458ea8831ae097c631b1160c01 (diff)
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: [<ffffffff8138283b>] genl_unregister_family+0x2b/0x130 #1: (rcu_read_lock){.+.+..}, at: [<ffffffff8138270c>] __genl_unregister_mc_group+0x1c/0x120 Pid: 1510, comm: rmmod Not tainted 2.6.31-wl #444 Call Trace: [<ffffffff81044ff9>] __might_sleep+0x119/0x150 [<ffffffff81380501>] netlink_table_grab+0x21/0x100 [<ffffffff813813a3>] netlink_clear_multicast_users+0x23/0x60 [<ffffffff81382761>] __genl_unregister_mc_group+0x71/0x120 [<ffffffff81382866>] genl_unregister_family+0x56/0x130 [<ffffffffa0007d85>] nl80211_exit+0x15/0x20 [cfg80211] [<ffffffffa000005a>] 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 <johannes@sipsolutions.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/netlink/genetlink.c')
-rw-r--r--net/netlink/genetlink.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index 566941e0336..44ff3f3810f 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -220,10 +220,12 @@ static void __genl_unregister_mc_group(struct genl_family *family,
struct net *net;
BUG_ON(grp->family != family);
+ netlink_table_grab();
rcu_read_lock();
for_each_net_rcu(net)
- netlink_clear_multicast_users(net->genl_sock, grp->id);
+ __netlink_clear_multicast_users(net->genl_sock, grp->id);
rcu_read_unlock();
+ netlink_table_ungrab();
clear_bit(grp->id, mc_groups);
list_del(&grp->list);