From cbc1dd5b659f5a2c3cba88b197b7443679bb35a0 Mon Sep 17 00:00:00 2001 From: Chen Zhongjin Date: Tue, 1 Nov 2022 19:52:52 +0800 Subject: [PATCH] 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: register_pernet_subsys+0x29/0x40 ebtables_init+0x58/0x1000 [ebtables] ... Fixes: 820dc0523e05 ("net: netfilter: move bpf_ct_set_nat_info kfunc in nf_nat_bpf.c") Signed-off-by: Chen Zhongjin Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_nat_core.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c index 18319a6e6806..e29e4ccb5c5a 100644 --- a/net/netfilter/nf_nat_core.c +++ b/net/netfilter/nf_nat_core.c @@ -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)