[PATCH nf-next v2 1/2] netfilter: Fix potential null pointer dereference
From: Aaron Conole <hidden>
Date: 2016-09-27 13:38:34
Also in:
netfilter-devel
Subsystem:
netfilter, networking [general], the rest · Maintainers:
Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
It's possible for nf_hook_entry_head to return NULL if two nf_unregister_net_hook calls happen simultaneously with a single hook entry in the list. This fix ensures that no null pointer dereference could occur when such a race happens. Signed-off-by: Aaron Conole <redacted> --- net/netfilter/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/netfilter/core.c b/net/netfilter/core.c
index 360c63d..e58e420 100644
--- a/net/netfilter/core.c
+++ b/net/netfilter/core.c@@ -160,7 +160,7 @@ void nf_unregister_net_hook(struct net *net, const struct nf_hook_ops *reg) mutex_lock(&nf_hook_mutex); hooks_entry = nf_hook_entry_head(net, reg); - if (hooks_entry->orig_ops == reg) { + if (hooks_entry && hooks_entry->orig_ops == reg) { nf_set_hooks_head(net, reg, nf_entry_dereference(hooks_entry->next)); goto unlock;
--
2.7.4