can: proc: can_remove_proc(): silence remove_proc_entry warning

commit 3accbfdc36130282f5ae9e6eecfdf820169fedce upstream.

If can_init_proc() fail to create /proc/net/can directory, can_remove_proc()
will trigger a warning:

WARNING: CPU: 6 PID: 7133 at fs/proc/generic.c:672 remove_proc_entry+0x17b0
Kernel panic - not syncing: panic_on_warn set ...

Fix to return early from can_remove_proc() if can proc_dir does not exists.

Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Link: https://lore.kernel.org/r/1594709090-3203-1-git-send-email-zhangchangzhong@huawei.com
Fixes: 8e8cda6d737d ("can: initial support for network namespaces")
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/can/proc.c b/net/can/proc.c
index e6881bfc3ed1120e3ef496ab9a751b7aebe2df24..077af42c26ba5cb3a18205c1baf626de9caa806c 100644 (file)
--- a/net/can/proc.c
+++ b/net/can/proc.c
@@ -471,6 +471,9 @@ void can_init_proc(struct net *net)
  */
 void can_remove_proc(struct net *net)
 {
+       if (!net->can.proc_dir)
+               return;
+
        if (net->can.pde_version)
                remove_proc_entry(CAN_PROC_VERSION, net->can.proc_dir);
 
@@ -498,6 +501,5 @@ void can_remove_proc(struct net *net)
        if (net->can.pde_rcvlist_sff)
                remove_proc_entry(CAN_PROC_RCVLIST_SFF, net->can.proc_dir);
 
-       if (net->can.proc_dir)
-               remove_proc_entry("can", net->proc_net);
+       remove_proc_entry("can", net->proc_net);
 }