possible deadlock in team_device_event (2)

Status: upstream: reported syz repro on 2026/10/21 12:03
Reported-by: syzbot+570c31c7ca2a22cd964f@syzkaller.appspotmail.com
First crash: 12d, last: 10m
▶ ▼ Similar bugs (7)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 possible deadlock in team_device_event 4 5 194d 393d 0/2 auto-obsoleted due to no activity on 2026/07/31 14:32
upstream possible deadlock in team_device_event net 4 30 2252d 2320d 0/29 auto-closed as invalid on 2020/12/31 13:59
linux-5.15 possible deadlock in team_device_event (2) 4 2 217d 229d 0/3 auto-obsoleted due to no activity on 2026/07/08 12:05
upstream possible deadlock in team_device_event (3) net 4 syz, C error 38569 436d 907d 29/29 fixed on 2025/09/04 16:57
upstream possible deadlock in team_device_event (2) net 4 8 1799d 2035d 0/29 auto-closed as invalid on 2022/03/29 04:55
linux-6.1 possible deadlock in team_device_event 4 2 88d 93d 0/3 upstream: reported on 2026/08/01 06:26
linux-5.15 possible deadlock in team_device_event 4 1 385d 385d 0/3 auto-obsoleted due to no activity on 2026/01/21 16:55

Sample crash report:
netdevsim netdevsim0 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
kworker/u4:5/139 is trying to acquire lock:
ffff88802e524dc0 (team->team_lock_key#2){+.+.}-{3:3}, at: team_del_slave_on_unregister drivers/net/team/team_core.c:2046 [inline]
ffff88802e524dc0 (team->team_lock_key#2){+.+.}-{3:3}, at: team_device_event+0x295/0xc50 drivers/net/team/team_core.c:3152

but task is already holding lock:
ffff88802dab8768 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: wiphy_lock include/net/cfg80211.h:5878 [inline]
ffff88802dab8768 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: ieee80211_remove_interfaces+0x2bd/0x690 net/mac80211/iface.c:2379

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&rdev->wiphy.mtx){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x135/0xce0 kernel/locking/mutex.c:747
       wiphy_lock include/net/cfg80211.h:5878 [inline]
       ieee80211_open+0x144/0x200 net/mac80211/iface.c:470
       __dev_open+0x2cb/0x430 net/core/dev.c:1519
       dev_open+0xab/0x190 net/core/dev.c:1555
       team_port_add drivers/net/team/team_core.c:1243 [inline]
       team_add_slave+0x703/0x28a0 drivers/net/team/team_core.c:2010
       do_set_master net/core/rtnetlink.c:2723 [inline]
       do_setlink+0xda4/0x3f00 net/core/rtnetlink.c:2929
       __rtnl_newlink net/core/rtnetlink.c:3720 [inline]
       rtnl_newlink+0x1848/0x2170 net/core/rtnetlink.c:3767
       rtnetlink_rcv_msg+0x843/0xf90 net/core/rtnetlink.c:6489
       netlink_rcv_skb+0x235/0x4c0 net/netlink/af_netlink.c:2554
       netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
       netlink_unicast+0x856/0x9e0 net/netlink/af_netlink.c:1346
       netlink_sendmsg+0x8d0/0xbf0 net/netlink/af_netlink.c:1903
       sock_sendmsg_nosec net/socket.c:730 [inline]
       __sock_sendmsg net/socket.c:745 [inline]
       ____sys_sendmsg+0x61b/0x980 net/socket.c:2595
       ___sys_sendmsg+0x2a6/0x360 net/socket.c:2649
       __sys_sendmsg net/socket.c:2678 [inline]
       __do_sys_sendmsg net/socket.c:2687 [inline]
       __se_sys_sendmsg+0x1d0/0x2c0 net/socket.c:2685
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (team->team_lock_key#2){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3162 [inline]
       check_prevs_add kernel/locking/lockdep.c:3281 [inline]
       validate_chain kernel/locking/lockdep.c:3897 [inline]
       __lock_acquire+0x3a07/0x7eb0 kernel/locking/lockdep.c:5171
       lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5790
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x135/0xce0 kernel/locking/mutex.c:747
       team_del_slave_on_unregister drivers/net/team/team_core.c:2046 [inline]
       team_device_event+0x295/0xc50 drivers/net/team/team_core.c:3152
       notifier_call_chain+0x18f/0x380 kernel/notifier.c:93
       call_netdevice_notifiers_extack net/core/dev.c:2077 [inline]
       call_netdevice_notifiers net/core/dev.c:2091 [inline]
       unregister_netdevice_many_notify+0x1037/0x1910 net/core/dev.c:11225
       unregister_netdevice_many net/core/dev.c:11281 [inline]
       unregister_netdevice_queue+0x2e9/0x330 net/core/dev.c:11161
       unregister_netdevice include/linux/netdevice.h:3198 [inline]
       _cfg80211_unregister_wdev+0x16c/0x5a0 net/wireless/core.c:1245
       ieee80211_remove_interfaces+0x4b3/0x690 net/mac80211/iface.c:2398
       ieee80211_unregister_hw+0x5d/0x2a0 net/mac80211/main.c:1522
       mac80211_hwsim_del_radio+0x289/0x480 drivers/net/wireless/virtual/mac80211_hwsim.c:5418
       hwsim_exit_net+0x58d/0x650 drivers/net/wireless/virtual/mac80211_hwsim.c:6300
       ops_exit_list net/core/net_namespace.c:173 [inline]
       cleanup_net+0x6f7/0xb00 net/core/net_namespace.c:656
       process_one_work kernel/workqueue.c:2657 [inline]
       process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734
       worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815
       kthread+0x2fa/0x390 kernel/kthread.c:388
       ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
       ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&rdev->wiphy.mtx);
                               lock(team->team_lock_key#2);
                               lock(&rdev->wiphy.mtx);
  lock(team->team_lock_key#2);

 *** DEADLOCK ***

5 locks held by kworker/u4:5/139:
 #0: ffff888140049138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff888140049138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc90002dafd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc90002dafd00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #2: ffffffff8f3db1d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x140/0xb00 net/core/net_namespace.c:610
 #3: ffffffff8f3e83c8 (rtnl_mutex){+.+.}-{3:3}, at: ieee80211_unregister_hw+0x55/0x2a0 net/mac80211/main.c:1515
 #4: ffff88802dab8768 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: wiphy_lock include/net/cfg80211.h:5878 [inline]
 #4: ffff88802dab8768 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: ieee80211_remove_interfaces+0x2bd/0x690 net/mac80211/iface.c:2379

stack backtrace:
CPU: 0 PID: 139 Comm: kworker/u4:5 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 check_noncircular+0x2fc/0x400 kernel/locking/lockdep.c:2215
 check_prev_add kernel/locking/lockdep.c:3162 [inline]
 check_prevs_add kernel/locking/lockdep.c:3281 [inline]
 validate_chain kernel/locking/lockdep.c:3897 [inline]
 __lock_acquire+0x3a07/0x7eb0 kernel/locking/lockdep.c:5171
 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5790
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x135/0xce0 kernel/locking/mutex.c:747
 team_del_slave_on_unregister drivers/net/team/team_core.c:2046 [inline]
 team_device_event+0x295/0xc50 drivers/net/team/team_core.c:3152
 notifier_call_chain+0x18f/0x380 kernel/notifier.c:93
 call_netdevice_notifiers_extack net/core/dev.c:2077 [inline]
 call_netdevice_notifiers net/core/dev.c:2091 [inline]
 unregister_netdevice_many_notify+0x1037/0x1910 net/core/dev.c:11225
 unregister_netdevice_many net/core/dev.c:11281 [inline]
 unregister_netdevice_queue+0x2e9/0x330 net/core/dev.c:11161
 unregister_netdevice include/linux/netdevice.h:3198 [inline]
 _cfg80211_unregister_wdev+0x16c/0x5a0 net/wireless/core.c:1245
 ieee80211_remove_interfaces+0x4b3/0x690 net/mac80211/iface.c:2398
 ieee80211_unregister_hw+0x5d/0x2a0 net/mac80211/main.c:1522
 mac80211_hwsim_del_radio+0x289/0x480 drivers/net/wireless/virtual/mac80211_hwsim.c:5418
 hwsim_exit_net+0x58d/0x650 drivers/net/wireless/virtual/mac80211_hwsim.c:6300
 ops_exit_list net/core/net_namespace.c:173 [inline]
 cleanup_net+0x6f7/0xb00 net/core/net_namespace.c:656
 process_one_work kernel/workqueue.c:2657 [inline]
 process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734
 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
team0: Port device wlan1 removed
hsr_slave_0: left promiscuous mode
hsr_slave_1: left promiscuous mode
batman_adv: batadv0: Interface deactivated: batadv_slave_0
batman_adv: batadv0: Removing interface: batadv_slave_0
batman_adv: batadv0: Interface deactivated: batadv_slave_1
batman_adv: batadv0: Removing interface: batadv_slave_1
bridge_slave_1: left allmulticast mode
bridge_slave_1: left promiscuous mode
bridge0: port 2(bridge_slave_1) entered disabled state
bridge_slave_0: left allmulticast mode
bridge_slave_0: left promiscuous mode
bridge0: port 1(bridge_slave_0) entered disabled state
veth1_macvtap: left promiscuous mode
veth0_macvtap: left promiscuous mode
veth1_vlan: left promiscuous mode
veth0_vlan: left promiscuous mode
team0 (unregistering): Port device team_slave_1 removed
team0 (unregistering): Port device team_slave_0 removed
bond0 (unregistering): (slave bond_slave_1): Releasing backup interface
bond0 (unregistering): (slave bond_slave_0): Releasing backup interface
bond0 (unregistering): Released all slaves
wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50

Crashes (731):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/11/02 09:15 linux-6.6.y b5a1dc3ad482 25a0ae84 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/11/02 17:18 linux-6.6.y b5a1dc3ad482 6969b601 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/11/02 15:26 linux-6.6.y b5a1dc3ad482 6969b601 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/11/02 11:09 linux-6.6.y b5a1dc3ad482 6969b601 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in team_device_event
2026/11/02 09:35 linux-6.6.y b5a1dc3ad482 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/11/02 06:04 linux-6.6.y b5a1dc3ad482 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/11/02 04:28 linux-6.6.y b5a1dc3ad482 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/11/02 03:11 linux-6.6.y b5a1dc3ad482 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/11/02 02:01 linux-6.6.y b5a1dc3ad482 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/11/02 01:23 linux-6.6.y b5a1dc3ad482 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/11/02 00:04 linux-6.6.y b5a1dc3ad482 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/11/01 22:48 linux-6.6.y b5a1dc3ad482 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/11/01 21:48 linux-6.6.y b5a1dc3ad482 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/11/01 20:36 linux-6.6.y b5a1dc3ad482 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/11/01 18:58 linux-6.6.y b5a1dc3ad482 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/11/01 17:37 linux-6.6.y b5a1dc3ad482 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/11/01 16:22 linux-6.6.y b5a1dc3ad482 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/11/01 16:10 linux-6.6.y b5a1dc3ad482 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/11/01 15:04 linux-6.6.y b5a1dc3ad482 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/11/01 13:59 linux-6.6.y b5a1dc3ad482 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in team_device_event
2026/11/01 12:11 linux-6.6.y b5a1dc3ad482 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/11/01 11:20 linux-6.6.y b5a1dc3ad482 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/11/01 09:34 linux-6.6.y b5a1dc3ad482 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/11/01 08:27 linux-6.6.y b5a1dc3ad482 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/11/01 08:18 linux-6.6.y b5a1dc3ad482 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/11/01 07:17 linux-6.6.y b5a1dc3ad482 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/11/01 04:23 linux-6.6.y b5a1dc3ad482 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/11/01 01:00 linux-6.6.y b5a1dc3ad482 2041d3f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/10/31 23:52 linux-6.6.y b5a1dc3ad482 2041d3f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/10/31 23:12 linux-6.6.y b5a1dc3ad482 2041d3f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/10/31 22:10 linux-6.6.y b5a1dc3ad482 2041d3f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/10/31 21:56 linux-6.6.y b5a1dc3ad482 2041d3f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/10/31 20:48 linux-6.6.y b5a1dc3ad482 2041d3f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/10/31 19:44 linux-6.6.y b5a1dc3ad482 2041d3f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/10/31 18:39 linux-6.6.y b5a1dc3ad482 2041d3f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/10/31 17:37 linux-6.6.y b5a1dc3ad482 2041d3f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/10/31 13:11 linux-6.6.y b5a1dc3ad482 2041d3f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/10/31 12:31 linux-6.6.y b5a1dc3ad482 2041d3f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in team_device_event
2026/10/31 11:26 linux-6.6.y b5a1dc3ad482 2041d3f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/10/31 08:17 linux-6.6.y b5a1dc3ad482 0ec395f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/10/31 06:49 linux-6.6.y b5a1dc3ad482 0ec395f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/10/31 04:34 linux-6.6.y b5a1dc3ad482 0ec395f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/10/31 02:35 linux-6.6.y b5a1dc3ad482 0ec395f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/10/31 01:21 linux-6.6.y b5a1dc3ad482 0ec395f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/10/30 19:51 linux-6.6.y b5a1dc3ad482 0ec395f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/10/30 10:17 linux-6.6.y 0aebf2870d53 b498adee .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/10/30 09:08 linux-6.6.y 0aebf2870d53 b498adee .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
2026/10/21 12:02 linux-6.6.y 0aebf2870d53 61c200c7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in team_device_event
* Struck through repros no longer work on HEAD.