Commit cbc1dd5b authored by Chen Zhongjin's avatar Chen Zhongjin Committed by Pablo Neira Ayuso
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netfilter: nf_nat: Fix possible memory leak in nf_nat_init() 



In nf_nat_init(), register_nf_nat_bpf() can fail and return directly
without any error handling.
Then nf_nat_bysource will leak and registering of &nat_net_ops,
&follow_master_nat and nf_nat_hook won't be reverted.

This leaves wild ops in linkedlists and when another module tries to
call register_pernet_operations() or nf_ct_helper_expectfn_register()
it triggers page fault:

 BUG: unable to handle page fault for address: fffffbfff81b964c
 RIP: 0010:register_pernet_operations+0x1b9/0x5f0
 Call Trace:
 <TASK>
  register_pernet_subsys+0x29/0x40
  ebtables_init+0x58/0x1000 [ebtables]
  ...

Fixes: 820dc052 ("net: netfilter: move bpf_ct_set_nat_info kfunc in nf_nat_bpf.c")
Signed-off-by: default avatarChen Zhongjin <chenzhongjin@huawei.com>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 5663ed63

net/netfilter/nf_nat_core.c

+10 −1
Original line number Diff line number Diff line
@@ -1152,7 +1152,16 @@ static int __init nf_nat_init(void) 
	WARN_ON(nf_nat_hook != NULL);

	RCU_INIT_POINTER(nf_nat_hook, &nat_hook);



	return register_nf_nat_bpf();

	ret = register_nf_nat_bpf();

	if (ret < 0) {

		RCU_INIT_POINTER(nf_nat_hook, NULL);

		nf_ct_helper_expectfn_unregister(&follow_master_nat);

		synchronize_net();

		unregister_pernet_subsys(&nat_net_ops);

		kvfree(nf_nat_bysource);

	}



	return ret;

}



static void __exit nf_nat_cleanup(void)