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: 820dc0523e05 ("net: netfilter: move bpf_ct_set_nat_info kfunc in nf_nat_bpf.c")
Signed-off-by: Chen Zhongjin <chenzhongjin@xxxxxxxxxx>
---
Also revert the operation for &follow_master_nat and nf_nat_hook,
then slightly fix commit msg for it.
---
net/netfilter/nf_nat_core.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c
index 18319a6e6806..47aa67abd531 100644
--- a/net/netfilter/nf_nat_core.c
+++ b/net/netfilter/nf_nat_core.c
@@ -1152,7 +1152,15 @@ 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)
--
2.17.1
