Message-ID: <67936dd9.050a0220.2eae65.001a.GAE@google.com>
Date: Fri, 24 Jan 2025 02:39:21 -0800
From: syzbot <syzbot+f64ec90806724c999178@...kaller.appspotmail.com>
To: johannes@...solutions.net, linux-kernel@...r.kernel.org, 
	linux-wireless@...r.kernel.org, netdev@...r.kernel.org, 
	syzkaller-bugs@...glegroups.com
Subject: [syzbot] [wireless?] upstream test error: possible deadlock in ieee80211_remove_interfaces

Hello,

syzbot found the following issue on:

HEAD commit:    bc8198dc7ebc Merge tag 'sched_ext-for-6.14' of git://git.k..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10763ab0580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=faaefa8d73d72fff
dashboard link: https://syzkaller.appspot.com/bug?extid=f64ec90806724c999178
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/3af0795be8e4/disk-bc8198dc.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/630156792aa7/vmlinux-bc8198dc.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f2c5067dd705/bzImage-bc8198dc.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f64ec90806724c999178@...kaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
6.13.0-syzkaller-05252-gbc8198dc7ebc #0 Not tainted
------------------------------------------------------
kworker/u8:5/318 is trying to acquire lock:
ffffffff8fef6fa8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_acquire_if_cleanup_net net/core/dev.c:10272 [inline]
ffffffff8fef6fa8 (rtnl_mutex){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1a51/0x21a0 net/core/dev.c:11792

but task is already holding lock:
ffff888073480768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6061 [inline]
ffff888073480768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: ieee80211_remove_interfaces+0xf1/0x720 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}:
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730
       wiphy_lock include/net/cfg80211.h:6046 [inline]
       wiphy_register+0x1c9c/0x2860 net/wireless/core.c:1006
       ieee80211_register_hw+0x2455/0x4060 net/mac80211/main.c:1587
       mac80211_hwsim_new_radio+0x304e/0x54d0 drivers/net/wireless/virtual/mac80211_hwsim.c:5558
       init_mac80211_hwsim+0x432/0x8c0 drivers/net/wireless/virtual/mac80211_hwsim.c:6910
       do_one_initcall+0x128/0x700 init/main.c:1267
       do_initcall_level init/main.c:1329 [inline]
       do_initcalls init/main.c:1345 [inline]
       do_basic_setup init/main.c:1364 [inline]
       kernel_init_freeable+0x5c7/0x900 init/main.c:1578
       kernel_init+0x1c/0x2b0 init/main.c:1467
       ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
       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:3163 [inline]
       check_prevs_add kernel/locking/lockdep.c:3282 [inline]
       validate_chain kernel/locking/lockdep.c:3906 [inline]
       __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228
       lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730
       rtnl_acquire_if_cleanup_net net/core/dev.c:10272 [inline]
       unregister_netdevice_many_notify+0x1a51/0x21a0 net/core/dev.c:11792
       unregister_netdevice_many net/core/dev.c:11875 [inline]
       unregister_netdevice_queue+0x307/0x3f0 net/core/dev.c:11741
       unregister_netdevice include/linux/netdevice.h:3329 [inline]
       _cfg80211_unregister_wdev+0x64b/0x830 net/wireless/core.c:1251
       ieee80211_remove_interfaces+0x34f/0x720 net/mac80211/iface.c:2305
       ieee80211_unregister_hw+0x55/0x3a0 net/mac80211/main.c:1681
       mac80211_hwsim_del_radio drivers/net/wireless/virtual/mac80211_hwsim.c:5664 [inline]
       hwsim_exit_net+0x3ad/0x7d0 drivers/net/wireless/virtual/mac80211_hwsim.c:6544
       ops_exit_list+0xb0/0x180 net/core/net_namespace.c:172
       cleanup_net+0x5c6/0xbf0 net/core/net_namespace.c:652
       process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3236
       process_scheduled_works kernel/workqueue.c:3317 [inline]
       worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398
       kthread+0x3af/0x750 kernel/kthread.c:464
       ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
       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/u8:5/318:
 #0: ffff88801beeb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3211
 #1: ffffc90003017d18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3212
 #2: ffffffff8fee1390 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xca/0xbf0 net/core/net_namespace.c:606
 #3: ffff888073480768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6061 [inline]
 #3: ffff888073480768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: ieee80211_remove_interfaces+0xf1/0x720 net/mac80211/iface.c:2280

stack backtrace:
CPU: 0 UID: 0 PID: 318 Comm: kworker/u8:5 Not tainted 6.13.0-syzkaller-05252-gbc8198dc7ebc #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+0x116/0x1f0 lib/dump_stack.c:120
 print_circular_bug+0x490/0x760 kernel/locking/lockdep.c:2076
 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2208
 check_prev_add kernel/locking/lockdep.c:3163 [inline]
 check_prevs_add kernel/locking/lockdep.c:3282 [inline]
 validate_chain kernel/locking/lockdep.c:3906 [inline]
 __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228
 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851
 __mutex_lock_common kernel/locking/mutex.c:585 [inline]
 __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730
 rtnl_acquire_if_cleanup_net net/core/dev.c:10272 [inline]
 unregister_netdevice_many_notify+0x1a51/0x21a0 net/core/dev.c:11792
 unregister_netdevice_many net/core/dev.c:11875 [inline]
 unregister_netdevice_queue+0x307/0x3f0 net/core/dev.c:11741
 unregister_netdevice include/linux/netdevice.h:3329 [inline]
 _cfg80211_unregister_wdev+0x64b/0x830 net/wireless/core.c:1251
 ieee80211_remove_interfaces+0x34f/0x720 net/mac80211/iface.c:2305
 ieee80211_unregister_hw+0x55/0x3a0 net/mac80211/main.c:1681
 mac80211_hwsim_del_radio drivers/net/wireless/virtual/mac80211_hwsim.c:5664 [inline]
 hwsim_exit_net+0x3ad/0x7d0 drivers/net/wireless/virtual/mac80211_hwsim.c:6544
 ops_exit_list+0xb0/0x180 net/core/net_namespace.c:172
 cleanup_net+0x5c6/0xbf0 net/core/net_namespace.c:652
 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3236
 process_scheduled_works kernel/workqueue.c:3317 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398
 kthread+0x3af/0x750 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
bond0 (unregistering): Released all slaves


---
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