ipv6: fix WARNING in ip6_route_net_exit_late()

During the initialization of ip6_route_net_init_late(), if file
ipv6_route or rt6_stats fails to be created, the initialization is
successful by default. Therefore, the ipv6_route or rt6_stats file
doesn't be found during the remove in ip6_route_net_exit_late(). It
will cause WRNING.

The following is the stack information:
name 'rt6_stats'
WARNING: CPU: 0 PID: 9 at fs/proc/generic.c:712 remove_proc_entry+0x389/0x460
Modules linked in:
Workqueue: netns cleanup_net
RIP: 0010:remove_proc_entry+0x389/0x460
PKRU: 55555554
Call Trace:
<TASK>
ops_exit_list+0xb0/0x170
cleanup_net+0x4ea/0xb00
process_one_work+0x9bf/0x1710
worker_thread+0x665/0x1080
kthread+0x2e4/0x3a0
ret_from_fork+0x1f/0x30
</TASK>

Fixes: cdb1876192db ("[NETNS][IPV6] route6 - create route6 proc files for the namespace")
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20221102020610.351330-1-shaozhengchao@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 69252eb462b2d2f2612edd3d84e34ce1686a24ca..2f355f0ec32ac2fa5ae56db82c2c3632a3e58996 100644 (file)
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -6555,10 +6555,16 @@ static void __net_exit ip6_route_net_exit(struct net *net)
 static int __net_init ip6_route_net_init_late(struct net *net)
 {
 #ifdef CONFIG_PROC_FS
-       proc_create_net("ipv6_route", 0, net->proc_net, &ipv6_route_seq_ops,
-                       sizeof(struct ipv6_route_iter));
-       proc_create_net_single("rt6_stats", 0444, net->proc_net,
-                       rt6_stats_seq_show, NULL);
+       if (!proc_create_net("ipv6_route", 0, net->proc_net,
+                            &ipv6_route_seq_ops,
+                            sizeof(struct ipv6_route_iter)))
+               return -ENOMEM;
+
+       if (!proc_create_net_single("rt6_stats", 0444, net->proc_net,
+                                   rt6_stats_seq_show, NULL)) {
+               remove_proc_entry("ipv6_route", net->proc_net);
+               return -ENOMEM;
+       }
 #endif
        return 0;
 }