syzbot
net-next test error: possible deadlock in ieee80211_remove_interfaces
Status: fixed on 2025/05/06 15:33
Subsystems:
wireless
[Documentation on labels]
Fix commit:
e759e1e4a4bd
net: revert RTNL changes in unregister_netdevice_many_notify()
First crash: 571d, last: 565d
Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
6.13.0-rc7-syzkaller-01620-gcf33d96f5090 #0 Not tainted
------------------------------------------------------
kworker/u8:8/4898 is trying to acquire lock:
ffffffff8fcb4e08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_acquire_if_cleanup_net net/core/dev.c:10272 [inline]
ffffffff8fcb4e08 (rtnl_mutex){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0xac2/0x2030 net/core/dev.c:11792
but task is already holding lock:
ffff888067db8768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6061 [inline]
ffff888067db8768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: ieee80211_remove_interfaces+0x129/0x700 net/mac80211/iface.c:2280
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&rdev->wiphy.mtx){+.+.}-{4:4}:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
__mutex_lock_common kernel/locking/mutex.c:585 [inline]
__mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735
wiphy_lock include/net/cfg80211.h:6046 [inline]
wiphy_register+0x1a49/0x27b0 net/wireless/core.c:1006
ieee80211_register_hw+0x354e/0x4240 net/mac80211/main.c:1587
mac80211_hwsim_new_radio+0x2a9f/0x4a90 drivers/net/wireless/virtual/mac80211_hwsim.c:5558
init_mac80211_hwsim+0x87a/0xb00 drivers/net/wireless/virtual/mac80211_hwsim.c:6910
do_one_initcall+0x248/0x870 init/main.c:1266
do_initcall_level+0x157/0x210 init/main.c:1328
do_initcalls+0x3f/0x80 init/main.c:1344
kernel_init_freeable+0x435/0x5d0 init/main.c:1577
kernel_init+0x1d/0x2b0 init/main.c:1466
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
-> #0 (rtnl_mutex){+.+.}-{4:4}:
check_prev_add kernel/locking/lockdep.c:3161 [inline]
check_prevs_add kernel/locking/lockdep.c:3280 [inline]
validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
__lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
__mutex_lock_common kernel/locking/mutex.c:585 [inline]
__mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735
rtnl_acquire_if_cleanup_net net/core/dev.c:10272 [inline]
unregister_netdevice_many_notify+0xac2/0x2030 net/core/dev.c:11792
unregister_netdevice_many net/core/dev.c:11875 [inline]
unregister_netdevice_queue+0x303/0x370 net/core/dev.c:11741
unregister_netdevice include/linux/netdevice.h:3329 [inline]
_cfg80211_unregister_wdev+0x163/0x590 net/wireless/core.c:1251
ieee80211_remove_interfaces+0x4ef/0x700 net/mac80211/iface.c:2305
ieee80211_unregister_hw+0x5d/0x2c0 net/mac80211/main.c:1681
mac80211_hwsim_del_radio+0x2c4/0x4c0 drivers/net/wireless/virtual/mac80211_hwsim.c:5664
hwsim_exit_net+0x5c1/0x670 drivers/net/wireless/virtual/mac80211_hwsim.c:6544
ops_exit_list net/core/net_namespace.c:172 [inline]
cleanup_net+0x812/0xd60 net/core/net_namespace.c:652
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317
worker_thread+0x870/0xd30 kernel/workqueue.c:3398
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&rdev->wiphy.mtx);
lock(rtnl_mutex);
lock(&rdev->wiphy.mtx);
lock(rtnl_mutex);
*** DEADLOCK ***
4 locks held by kworker/u8:8/4898:
#0: ffff88801baf5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff88801baf5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317
#1: ffffc900105c7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc900105c7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317
#2: ffffffff8fca8850 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x17a/0xd60 net/core/net_namespace.c:606
#3: ffff888067db8768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6061 [inline]
#3: ffff888067db8768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: ieee80211_remove_interfaces+0x129/0x700 net/mac80211/iface.c:2280
stack backtrace:
CPU: 0 UID: 0 PID: 4898 Comm: kworker/u8:8 Not tainted 6.13.0-rc7-syzkaller-01620-gcf33d96f5090 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Workqueue: netns cleanup_net
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074
check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206
check_prev_add kernel/locking/lockdep.c:3161 [inline]
check_prevs_add kernel/locking/lockdep.c:3280 [inline]
validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
__lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
__mutex_lock_common kernel/locking/mutex.c:585 [inline]
__mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735
rtnl_acquire_if_cleanup_net net/core/dev.c:10272 [inline]
unregister_netdevice_many_notify+0xac2/0x2030 net/core/dev.c:11792
unregister_netdevice_many net/core/dev.c:11875 [inline]
unregister_netdevice_queue+0x303/0x370 net/core/dev.c:11741
unregister_netdevice include/linux/netdevice.h:3329 [inline]
_cfg80211_unregister_wdev+0x163/0x590 net/wireless/core.c:1251
ieee80211_remove_interfaces+0x4ef/0x700 net/mac80211/iface.c:2305
ieee80211_unregister_hw+0x5d/0x2c0 net/mac80211/main.c:1681
mac80211_hwsim_del_radio+0x2c4/0x4c0 drivers/net/wireless/virtual/mac80211_hwsim.c:5664
hwsim_exit_net+0x5c1/0x670 drivers/net/wireless/virtual/mac80211_hwsim.c:6544
ops_exit_list net/core/net_namespace.c:172 [inline]
cleanup_net+0x812/0xd60 net/core/net_namespace.c:652
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317
worker_thread+0x870/0xd30 kernel/workqueue.c:3398
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
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
bond0 (unregistering): (slave bond_slave_0): Releasing backup interface
bond0 (unregistering): (slave bond_slave_1): Releasing backup interface
bond0 (unregistering): Released all slaves
hsr_slave_0: left promiscuous mode
hsr_slave_1: left promiscuous mode
batman_adv: batadv0: Removing interface: batadv_slave_0
batman_adv: batadv0: Removing interface: batadv_slave_1
team0 (unregistering): Port device team_slave_1 removed
team0 (unregistering): Port device team_slave_0 removed
* Struck through repros no longer work on HEAD.