From: Florian Westphal <fw@strlen.de>
Date: Fri, 7 Jan 2022 14:46:16 +0000 (+0100)
Subject: netfilter: egress: avoid a lockdep splat
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=6316136ec6e3dd1c302f7e7289a9ee46ecc610ae;p=linux.git
netfilter: egress: avoid a lockdep splat
include/linux/netfilter_netdev.h:97 suspicious rcu_dereference_check() usage!
2 locks held by sd-resolve/1100:
0: ..(rcu_read_lock_bh){1:3}, at: ip_finish_output2
1: ..(rcu_read_lock_bh){1:3}, at: __dev_queue_xmit
__dev_queue_xmit+0 ..
The helper has two callers, one uses rcu_read_lock, the other
rcu_read_lock_bh(). Annotate the dereference to reflect this.
Fixes: 42df6e1d221dd ("netfilter: Introduce egress hook")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
diff --git a/include/linux/netfilter_netdev.h b/include/linux/netfilter_netdev.h
index b71b57a83bb4f..b4dd96e4dc8dc 100644
--- a/include/linux/netfilter_netdev.h
+++ b/include/linux/netfilter_netdev.h
@@ -94,7 +94,7 @@ static inline struct sk_buff *nf_hook_egress(struct sk_buff *skb, int *rc,
return skb;
#endif
- e = rcu_dereference(dev->nf_hooks_egress);
+ e = rcu_dereference_check(dev->nf_hooks_egress, rcu_read_lock_bh_held());
if (!e)
return skb;