On 11/12/2020 14:29, Wang Hai wrote:
> I got a warining report:
>
> br_sysfs_addbr: can't create group bridge4/bridge
> ------------[ cut here ]------------
> sysfs group 'bridge' not found for kobject 'bridge4'
> WARNING: CPU: 2 PID: 9004 at fs/sysfs/group.c:279 sysfs_remove_group fs/sysfs/group.c:279 [inline]
> WARNING: CPU: 2 PID: 9004 at fs/sysfs/group.c:279 sysfs_remove_group+0x153/0x1b0 fs/sysfs/group.c:270
> Modules linked in: iptable_nat
> ...
> Call Trace:
> br_dev_delete+0x112/0x190 net/bridge/br_if.c:384
> br_dev_newlink net/bridge/br_netlink.c:1381 [inline]
> br_dev_newlink+0xdb/0x100 net/bridge/br_netlink.c:1362
> __rtnl_newlink+0xe11/0x13f0 net/core/rtnetlink.c:3441
> rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3500
> rtnetlink_rcv_msg+0x385/0x980 net/core/rtnetlink.c:5562
> netlink_rcv_skb+0x134/0x3d0 net/netlink/af_netlink.c:2494
> netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
> netlink_unicast+0x4a0/0x6a0 net/netlink/af_netlink.c:1330
> netlink_sendmsg+0x793/0xc80 net/netlink/af_netlink.c:1919
> sock_sendmsg_nosec net/socket.c:651 [inline]
> sock_sendmsg+0x139/0x170 net/socket.c:671
> ____sys_sendmsg+0x658/0x7d0 net/socket.c:2353
> ___sys_sendmsg+0xf8/0x170 net/socket.c:2407
> __sys_sendmsg+0xd3/0x190 net/socket.c:2440
> do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
> entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
> In br_device_event(), if the bridge sysfs fails to be added,
> br_device_event() should return error. This can prevent warining
> when removing bridge sysfs that do not exist.
>
> Fixes: bb900b27a2f4 ("bridge: allow creating bridge devices with netlink")
> Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> Signed-off-by: Wang Hai <wanghai38@xxxxxxxxxx>
> ---
> v1->v2: Fix this by check br_sysfs_addbr() return value as Nik's suggestion
> net/bridge/br.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/net/bridge/br.c b/net/bridge/br.c
> index 401eeb9142eb..1b169f8e7491 100644
> --- a/net/bridge/br.c
> +++ b/net/bridge/br.c
> @@ -43,7 +43,10 @@ static int br_device_event(struct notifier_block *unused, unsigned long event, v
>
> if (event == NETDEV_REGISTER) {
> /* register of bridge completed, add sysfs entries */
> - br_sysfs_addbr(dev);
> + err = br_sysfs_addbr(dev);
> + if (err)
> + return notifier_from_errno(err);
> +
> return NOTIFY_DONE;
> }
> }
>
Patch looks good, I also tested it with a notifier error injecting.
Tested-by: Nikolay Aleksandrov <nikolay@xxxxxxxxxx>
Acked-by: Nikolay Aleksandrov <nikolay@xxxxxxxxxx>
