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authorPatrick McHardy <kaber@trash.net>2007-02-27 12:56:42 -0500
committerDavid S. Miller <davem@sunset.davemloft.net>2007-02-28 12:42:13 -0500
commit4498121ca3acbf928681b71261227d28dc29b6f6 (patch)
treef6947b8bf2cee22498fcea4e9c447c4eed4b6998 /net
parent6548cda289b549ed60c35f16a0051609aeee2fd0 (diff)
[NET]: Handle disabled preemption in gfp_any()
ctnetlink uses netlink_unicast from an atomic_notifier_chain (which is called within a RCU read side critical section) without holding further locks. netlink_unicast calls netlink_trim with the result of gfp_any() for the gfp flags, which are passed down to pskb_expand_header. gfp_any() only checks for softirq context and returns GFP_KERNEL, resulting in this warning: BUG: sleeping function called from invalid context at mm/slab.c:3032 in_atomic():1, irqs_disabled():0 no locks held by rmmod/7010. Call Trace: [<ffffffff8109467f>] debug_show_held_locks+0x9/0xb [<ffffffff8100b0b4>] __might_sleep+0xd9/0xdb [<ffffffff810b5082>] __kmalloc+0x68/0x110 [<ffffffff811ba8f2>] pskb_expand_head+0x4d/0x13b [<ffffffff81053147>] netlink_broadcast+0xa5/0x2e0 [<ffffffff881cd1d7>] :nfnetlink:nfnetlink_send+0x83/0x8a [<ffffffff8834f6a6>] :nf_conntrack_netlink:ctnetlink_conntrack_event+0x94c/0x96a [<ffffffff810624d6>] notifier_call_chain+0x29/0x3e [<ffffffff8106251d>] atomic_notifier_call_chain+0x32/0x60 [<ffffffff881d266d>] :nf_conntrack:destroy_conntrack+0xa5/0x1d3 [<ffffffff881d194e>] :nf_conntrack:nf_ct_cleanup+0x8c/0x12c [<ffffffff881d4614>] :nf_conntrack:kill_l3proto+0x0/0x13 [<ffffffff881d482a>] :nf_conntrack:nf_conntrack_l3proto_unregister+0x90/0x94 [<ffffffff883551b3>] :nf_conntrack_ipv4:nf_conntrack_l3proto_ipv4_fini+0x2b/0x5d [<ffffffff8109d44f>] sys_delete_module+0x1b5/0x1e6 [<ffffffff8105f245>] trace_hardirqs_on_thunk+0x35/0x37 [<ffffffff8105911e>] system_call+0x7e/0x83 Since netlink_unicast is supposed to be callable from within RCU read side critical sections, make gfp_any() check for in_atomic() instead of in_softirq(). Additionally nfnetlink_send needs to use gfp_any() as well for the call to netlink_broadcast). Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/netfilter/nfnetlink.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c
index 11d504d0ac72..bf23e489e4cd 100644
--- a/net/netfilter/nfnetlink.c
+++ b/net/netfilter/nfnetlink.c
@@ -197,13 +197,12 @@ EXPORT_SYMBOL_GPL(nfnetlink_has_listeners);
197 197
198int nfnetlink_send(struct sk_buff *skb, u32 pid, unsigned group, int echo) 198int nfnetlink_send(struct sk_buff *skb, u32 pid, unsigned group, int echo)
199{ 199{
200 gfp_t allocation = in_interrupt() ? GFP_ATOMIC : GFP_KERNEL;
201 int err = 0; 200 int err = 0;
202 201
203 NETLINK_CB(skb).dst_group = group; 202 NETLINK_CB(skb).dst_group = group;
204 if (echo) 203 if (echo)
205 atomic_inc(&skb->users); 204 atomic_inc(&skb->users);
206 netlink_broadcast(nfnl, skb, pid, group, allocation); 205 netlink_broadcast(nfnl, skb, pid, group, gfp_any());
207 if (echo) 206 if (echo)
208 err = netlink_unicast(nfnl, skb, pid, MSG_DONTWAIT); 207 err = netlink_unicast(nfnl, skb, pid, MSG_DONTWAIT);
209 208