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charset=us-ascii Content-Disposition: inline In-Reply-To: <20241230205647.1338900-1-tavip@google.com> On Mon, Dec 30, 2024 at 12:56:47PM -0800, Octavian Purdila wrote: > Prevent adding a device which is already a team device lower, > e.g. adding veth0 if vlan1 was already added and veth0 is a lower of > vlan1. > > This is not useful in practice and can lead to recursive locking: > > $ ip link add veth0 type veth peer name veth1 > $ ip link set veth0 up > $ ip link set veth1 up > $ ip link add link veth0 name veth0.1 type vlan protocol 802.1Q id 1 > $ ip link add team0 type team > $ ip link set veth0.1 down > $ ip link set veth0.1 master team0 > team0: Port device veth0.1 added > $ ip link set veth0 down > $ ip link set veth0 master team0 > > ============================================ > WARNING: possible recursive locking detected > 6.13.0-rc2-virtme-00441-ga14a429069bb #46 Not tainted > -------------------------------------------- > ip/7684 is trying to acquire lock: > ffff888016848e00 (team->team_lock_key){+.+.}-{4:4}, at: team_device_event (drivers/net/team/team_core.c:2928 drivers/net/team/team_core.c:2951 drivers/net/team/team_core.c:2973) > > but task is already holding lock: > ffff888016848e00 (team->team_lock_key){+.+.}-{4:4}, at: team_add_slave (drivers/net/team/team_core.c:1147 drivers/net/team/team_core.c:1977) > > other info that might help us debug this: > Possible unsafe locking scenario: > > CPU0 > ---- > lock(team->team_lock_key); > lock(team->team_lock_key); > > *** DEADLOCK *** > > May be due to missing lock nesting notation > > 2 locks held by ip/7684: > > stack backtrace: > CPU: 3 UID: 0 PID: 7684 Comm: ip Not tainted 6.13.0-rc2-virtme-00441-ga14a429069bb #46 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 > Call Trace: > > dump_stack_lvl (lib/dump_stack.c:122) > print_deadlock_bug.cold (kernel/locking/lockdep.c:3040) > __lock_acquire (kernel/locking/lockdep.c:3893 kernel/locking/lockdep.c:5226) > ? netlink_broadcast_filtered (net/netlink/af_netlink.c:1548) > lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851) > ? team_device_event (drivers/net/team/team_core.c:2928 drivers/net/team/team_core.c:2951 drivers/net/team/team_core.c:2973) > ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 2)) > ? team_device_event (drivers/net/team/team_core.c:2928 drivers/net/team/team_core.c:2951 drivers/net/team/team_core.c:2973) > ? lock_acquire (kernel/locking/lockdep.c:5822) > ? team_device_event (drivers/net/team/team_core.c:2928 drivers/net/team/team_core.c:2951 drivers/net/team/team_core.c:2973) > __mutex_lock (kernel/locking/mutex.c:587 kernel/locking/mutex.c:735) > ? team_device_event (drivers/net/team/team_core.c:2928 drivers/net/team/team_core.c:2951 drivers/net/team/team_core.c:2973) > ? team_device_event (drivers/net/team/team_core.c:2928 drivers/net/team/team_core.c:2951 drivers/net/team/team_core.c:2973) > ? fib_sync_up (net/ipv4/fib_semantics.c:2167) > ? team_device_event (drivers/net/team/team_core.c:2928 drivers/net/team/team_core.c:2951 drivers/net/team/team_core.c:2973) > team_device_event (drivers/net/team/team_core.c:2928 drivers/net/team/team_core.c:2951 drivers/net/team/team_core.c:2973) > notifier_call_chain (kernel/notifier.c:85) > call_netdevice_notifiers_info (net/core/dev.c:1996) > __dev_notify_flags (net/core/dev.c:8993) > ? __dev_change_flags (net/core/dev.c:8975) > dev_change_flags (net/core/dev.c:9027) > vlan_device_event (net/8021q/vlan.c:85 net/8021q/vlan.c:470) > ? br_device_event (net/bridge/br.c:143) > notifier_call_chain (kernel/notifier.c:85) > call_netdevice_notifiers_info (net/core/dev.c:1996) > dev_open (net/core/dev.c:1519 net/core/dev.c:1505) > team_add_slave (drivers/net/team/team_core.c:1219 drivers/net/team/team_core.c:1977) > ? __pfx_team_add_slave (drivers/net/team/team_core.c:1972) > do_set_master (net/core/rtnetlink.c:2917) > do_setlink.isra.0 (net/core/rtnetlink.c:3117) > > Reported-by: syzbot+3c47b5843403a45aef57@syzkaller.appspotmail.com > Closes: https://syzkaller.appspot.com/bug?extid=3c47b5843403a45aef57 > Fixes: 3d249d4ca7d0 ("net: introduce ethernet teaming device") > Signed-off-by: Octavian Purdila > --- > drivers/net/team/team_core.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/net/team/team_core.c b/drivers/net/team/team_core.c > index c7690adec8db..dc7cbd6a9798 100644 > --- a/drivers/net/team/team_core.c > +++ b/drivers/net/team/team_core.c > @@ -1175,6 +1175,13 @@ static int team_port_add(struct team *team, struct net_device *port_dev, > return -EBUSY; > } > > + if (netdev_has_upper_dev(port_dev, dev)) { > + NL_SET_ERR_MSG(extack, "Device is already a lower device of the team interface"); > + netdev_err(dev, "Device %s is already a lower device of the team interface\n", > + portname); > + return -EBUSY; > + } > + > if (port_dev->features & NETIF_F_VLAN_CHALLENGED && > vlan_uses_dev(dev)) { > NL_SET_ERR_MSG(extack, "Device is VLAN challenged and team device has VLAN set up"); > -- > 2.47.1.613.gc27f4b7a9f-goog > Reviewed-by: Hangbin Liu