From: Zhang Changzhong <zhangchangzhong@xxxxxxxxxx> 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@xxxxxxxxxx> Link: https://lore.kernel.org/r/1594709090-3203-1-git-send-email-zhangchangzhong@xxxxxxxxxx Fixes: 8e8cda6d737d ("can: initial support for network namespaces") Acked-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx> Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/can/proc.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- 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); }
