syzbot


possible deadlock in ieee80211_unregister_hw

Status: upstream: reported on 2024/11/06 06:52
Subsystems: wireless
[Documentation on labels]
Reported-by: syzbot+ec6009b644ee5b5c28c8@syzkaller.appspotmail.com
First crash: 4d18h, last: 4d18h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [wireless?] possible deadlock in ieee80211_unregister_hw 0 (1) 2024/11/06 06:52

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
6.12.0-rc5-syzkaller-00291-g05b92660cdfe #0 Not tainted
------------------------------------------------------
kworker/u32:4/77 is trying to acquire lock:
but task is already holding lock:

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:
-> #1 (&rdev->wiphy.mtx){+.+.}-{3:3}:
       wiphy_lock include/net/cfg80211.h:6014 [inline]
       ieee80211_open+0x12f/0x260 net/mac80211/iface.c:449
       do_set_master+0x1bc/0x230 net/core/rtnetlink.c:2730
       __rtnl_newlink+0xc35/0x1920 net/core/rtnetlink.c:3725
       rtnetlink_rcv_msg+0x3c7/0xea0 net/core/rtnetlink.c:6675
       netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2551
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (team->team_lock_key#4){+.+.}-{3:3}:
       notifier_call_chain+0xb9/0x410 kernel/notifier.c:93
       unregister_netdevice include/linux/netdevice.h:3118 [inline]
       _cfg80211_unregister_wdev+0x64b/0x830 net/wireless/core.c:1211
       ieee80211_remove_interfaces+0x36d/0x760 net/mac80211/iface.c:2300
       process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229
       kthread+0x2c1/0x3a0 kernel/kthread.c:389

other info that might help us debug this:


       CPU0                    CPU1
  lock(&rdev->wiphy.mtx);
                               lock(&rdev->wiphy.mtx);

 *** DEADLOCK ***

 #3: ffffffff8fee34a8 (rtnl_mutex){+.+.}-{3:3}, at: ieee80211_unregister_hw+0x4d/0x3a0 net/mac80211/main.c:1664
stack backtrace:
CPU: 2 UID: 0 PID: 77 Comm: kworker/u32:4 Not tainted 6.12.0-rc5-syzkaller-00291-g05b92660cdfe #0
Call Trace:
 <TASK>
 print_circular_bug+0x41c/0x610 kernel/locking/lockdep.c:2074
 check_prev_add kernel/locking/lockdep.c:3161 [inline]
 check_prevs_add kernel/locking/lockdep.c:3280 [inline]
 validate_chain kernel/locking/lockdep.c:3904 [inline]
 __lock_acquire+0x250b/0x3ce0 kernel/locking/lockdep.c:5202
 __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
 call_netdevice_notifiers_extack net/core/dev.c:2034 [inline]
 call_netdevice_notifiers net/core/dev.c:2048 [inline]
 unregister_netdevice_many_notify+0x8d5/0x1e50 net/core/dev.c:11407
 ieee80211_unregister_hw+0x55/0x3a0 net/mac80211/main.c:1671
 cleanup_net+0x5b7/0xb40 net/core/net_namespace.c:626
 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/02 06:42 upstream 05b92660cdfe f00eed24 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in ieee80211_unregister_hw
* Struck through repros no longer work on HEAD.