Subject: [syzbot] [wireless?] possible deadlock in ieee80211_remove_interfaces

From: syzbot <[email-masked]>
Date: Thu, 05 Sep 2024 13:10:28 -0700

Hello,

syzbot found the following issue on:

HEAD commit:    431c1646e1f8 Linux 6.11-rc6
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=144a43db980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=931962fa28089080
dashboard link: https://syzkaller.appspot.com/bug?extid=5b9196ecf74447172a9a
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-431c1646.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/01c0dadd39ff/vmlinux-431c1646.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9e2259e440f7/bzImage-431c1646.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email-masked]

======================================================
WARNING: possible circular locking dependency detected
6.11.0-rc6-syzkaller #0 Not tainted
------------------------------------------------------
kworker/u32:7/1108 is trying to acquire lock:
but task is already holding lock:
ffff888055278768 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: wiphy_lock include/net/cfg80211.h:6014 [inline]
ffff888055278768 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: ieee80211_remove_interfaces+0xfe/0x760 net/mac80211/iface.c:2262

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:
-> #1 (&rdev->wiphy.mtx){+.+.}-{3:3}:
       dev_open net/core/dev.c:1510 [inline]
       dev_open+0xf4/0x160 net/core/dev.c:1503
       do_setlink+0xd24/0x4190 net/core/rtnetlink.c:2907
       __rtnl_newlink+0xc35/0x1920 net/core/rtnetlink.c:3696
       rtnl_newlink+0x67/0xa0 net/core/rtnetlink.c:3743
       rtnetlink_rcv_msg+0x3c7/0xea0 net/core/rtnetlink.c:6647
       netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2550
       netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
       netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1357
       netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1901
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (team->team_lock_key#10){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3133 [inline]
       check_prevs_add kernel/locking/lockdep.c:3252 [inline]
       validate_chain kernel/locking/lockdep.c:3868 [inline]
       __lock_acquire+0x24ed/0x3cb0 kernel/locking/lockdep.c:5142
       lock_acquire kernel/locking/lockdep.c:5759 [inline]
       lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724
       __mutex_lock_common kernel/locking/mutex.c:608 [inline]
       __mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752
       team_del_slave+0x31/0x1b0 drivers/net/team/team_core.c:1990
       team_device_event+0xd0/0x770 drivers/net/team/team_core.c:2984
       notifier_call_chain+0xb9/0x410 kernel/notifier.c:93
       call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:1994
       call_netdevice_notifiers_extack net/core/dev.c:2032 [inline]
       call_netdevice_notifiers net/core/dev.c:2046 [inline]
       unregister_netdevice_many_notify+0x8bb/0x1e40 net/core/dev.c:11352
       mac80211_hwsim_del_radio drivers/net/wireless/virtual/mac80211_hwsim.c:5625 [inline]
       hwsim_exit_net+0x3ad/0x7d0 drivers/net/wireless/virtual/mac80211_hwsim.c:6505
       ops_exit_list+0xb0/0x180 net/core/net_namespace.c:173
       cleanup_net+0x5b7/0xbb0 net/core/net_namespace.c:640
       process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
       process_scheduled_works kernel/workqueue.c:3312 [inline]
       worker_thread+0x6c8/0xed0 kernel/workqueue.c:3389
       kthread+0x2c1/0x3a0 kernel/kthread.c:389
       ret_from_fork+0x45/0x80 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:

       ----                    ----
                               lock(&rdev->wiphy.mtx);
  lock(team->team_lock_key#10);

 *** DEADLOCK ***

5 locks held by kworker/u32:7/1108:
 #0: ffff88801baf4948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x1277/0x1b40 kernel/workqueue.c:3206
stack backtrace:
CPU: 2 UID: 0 PID: 1108 Comm: kworker/u32:7 Not tainted 6.11.0-rc6-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119
 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2186
 __mutex_lock_common kernel/locking/mutex.c:608 [inline]
 __mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752
 notifier_call_chain+0xb9/0x410 kernel/notifier.c:93
 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:1994
 call_netdevice_notifiers_extack net/core/dev.c:2032 [inline]
 call_netdevice_notifiers net/core/dev.c:2046 [inline]
 unregister_netdevice_many_notify+0x8bb/0x1e40 net/core/dev.c:11352
 unregister_netdevice_many net/core/dev.c:11414 [inline]
 unregister_netdevice_queue+0x307/0x3f0 net/core/dev.c:11289
 unregister_netdevice include/linux/netdevice.h:3129 [inline]
 _cfg80211_unregister_wdev+0x624/0x7f0 net/wireless/core.c:1211
 ieee80211_remove_interfaces+0x36d/0x760 net/mac80211/iface.c:2287
 ieee80211_unregister_hw+0x55/0x3a0 net/mac80211/main.c:1669
 mac80211_hwsim_del_radio drivers/net/wireless/virtual/mac80211_hwsim.c:5625 [inline]
 hwsim_exit_net+0x3ad/0x7d0 drivers/net/wireless/virtual/mac80211_hwsim.c:6505
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xed0 kernel/workqueue.c:3389
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

---
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