On Tue, 1 Dec 2020 22:01:14 +0800 Wang Hai wrote: > If adding bridge sysfs fails, br->ifobj will be NULL, there is no > need to delete its non-existent sysfs when deleting the bridge device, > otherwise, it will cause a warning. So, when br->ifobj == NULL, > directly return can fix this bug. > > 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 > > Reported-by: Hulk Robot <hulkci@xxxxxxxxxx> > Signed-off-by: Wang Hai <wanghai38@xxxxxxxxxx> Nik, is this the way you want to handle this? Should the notifier not fail if sysfs files cannot be created? Currently br_sysfs_addbr() returns an int but the only caller ignores it. > diff --git a/net/bridge/br_sysfs_br.c b/net/bridge/br_sysfs_br.c > index 7db06e3f642a..1e9cbf31d904 100644 > --- a/net/bridge/br_sysfs_br.c > +++ b/net/bridge/br_sysfs_br.c > @@ -991,6 +991,9 @@ void br_sysfs_delbr(struct net_device *dev) > struct kobject *kobj = &dev->dev.kobj; > struct net_bridge *br = netdev_priv(dev); > > + if (!br->ifobj) > + return; > + > kobject_put(br->ifobj); > sysfs_remove_bin_file(kobj, &bridge_forward); > sysfs_remove_group(kobj, &bridge_group);
