syzbot


BUG: workqueue lockup

Status: upstream: reported C repro on 2025/06/17 05:08
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+1fbf3f633f815f423a8c@syzkaller.appspotmail.com
First crash: 155d, last: 1d20h
Bug presence (1)
Date Name Commit Repro Result
2025/07/12 upstream (ToT) 3f31a806a62e C [report] WARNING in __cfg80211_ibss_joined
Similar bugs (16)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream BUG: workqueue lockup (4) block -1 C 47 2193d 2600d 15/29 fixed on 2019/12/13 00:31
linux-5.15 BUG: workqueue lockup missing-backport origin:upstream -1 C done 628 8d12h 984d 0/3 upstream: reported C repro on 2023/03/11 08:51
android-5-15 BUG: workqueue lockup origin:upstream missing-backport -1 C error 5555 11h54m 880d 0/2 upstream: reported C repro on 2023/06/22 22:19
upstream BUG: workqueue lockup (2) -1 C 406 2749d 2908d 5/29 fixed on 2018/05/13 10:02
linux-4.14 BUG: workqueue lockup -1 C 282 994d 2396d 0/1 upstream: reported C repro on 2019/04/29 11:26
upstream BUG: workqueue lockup -1 C 172 2930d 2941d 3/29 fixed on 2017/11/11 01:37
upstream BUG: workqueue lockup (5) net 1 C done 14190 1h59m 2135d 0/29 upstream: reported C repro on 2020/01/14 22:04
android-5-10 BUG: workqueue lockup (2) -1 C error 12396 3h17m 989d 0/2 upstream: reported C repro on 2023/03/05 21:10
upstream BUG: workqueue lockup (3) -1 C 1215 2694d 2746d 8/29 fixed on 2018/07/09 18:05
android-6-1 BUG: workqueue lockup origin:upstream missing-backport -1 C error 4918 2h41m 849d 0/2 upstream: reported C repro on 2023/07/23 17:25
android-414 BUG: workqueue lockup -1 C 114 2258d 2414d 0/1 public: reported C repro on 2019/04/11 00:00
linux-4.19 BUG: workqueue lockup -1 C error 41 988d 2402d 0/1 upstream: reported C repro on 2019/04/22 20:37
android-5-10 BUG: workqueue lockup -1 C error 25 1388d 1487d 0/2 closed as invalid on 2022/02/22 17:18
android-49 BUG: workqueue lockup -1 C 69 2182d 2414d 0/3 public: reported C repro on 2019/04/11 08:44
android-6-12 BUG: workqueue lockup -1 1 123d 123d 0/1 auto-obsoleted due to no activity on 2025/10/16 16:41
linux-6.1 BUG: workqueue lockup origin:upstream missing-backport -1 C unreliable 414 4d02h 987d 0/3 upstream: reported C repro on 2023/03/07 17:51

Sample crash report:
BUG: workqueue lockup - pool cpus=0 node=0 flags=0x0 nice=0 stuck for 201s!
BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=0 stuck for 202s!
BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=-20 stuck for 200s!
Showing busy workqueues and worker pools:
workqueue events: flags=0x0
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=5/256 refcnt=6
    pending: psi_avgs_work, 3*l2cap_info_timeout, kfree_rcu_monitor
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=9/256 refcnt=10
    in-flight: 8:request_firmware_work_func
    pending: vmstat_shepherd, ovs_dp_masks_rebalance, l2cap_info_timeout, 4*ovs_dp_masks_rebalance, kfree_rcu_monitor
workqueue events_long: flags=0x0
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=3/256 refcnt=4
    pending: 3*defense_work_handler
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=2/256 refcnt=3
    pending: 2*defense_work_handler
workqueue events_unbound: flags=0x2
  pwq 4: cpus=0-1 flags=0x4 nice=0 active=3/512 refcnt=4
    pending: toggle_allocation_gate, flush_memcg_stats_dwork, crng_reseed
workqueue events_freezable: flags=0x4
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2
    pending: update_balloon_stats_func
workqueue events_power_efficient: flags=0x80
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=4/256 refcnt=5
    pending: neigh_managed_work, gc_worker, neigh_periodic_work, do_cache_clean
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=4/256 refcnt=5
    pending: neigh_managed_work, reg_check_chans_work, neigh_periodic_work, check_lifetime
workqueue mm_percpu_wq: flags=0x8
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2
    pending: vmstat_update
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2
    pending: vmstat_update
workqueue writeback: flags=0x4a
  pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/256 refcnt=2
    pending: wb_workfn
workqueue kblockd: flags=0x18
  pwq 3: cpus=1 node=0 flags=0x0 nice=-20 active=1/256 refcnt=2
    pending: blk_mq_timeout_work
workqueue dm_bufio_cache: flags=0x8
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2
    pending: work_fn
workqueue ipv6_addrconf: flags=0xe000a
  pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/1 refcnt=4
    pending: addrconf_verify_work
workqueue krxrpcd: flags=0xa001a
  pwq 5: cpus=0-1 node=0 flags=0x4 nice=-20 active=1/1 refcnt=8
    pending: rxrpc_peer_keepalive_worker
    inactive: 4*rxrpc_peer_keepalive_worker
workqueue hci0: flags=0xa0012
  pwq 5: cpus=0-1 node=0 flags=0x4 nice=-20 active=1/1 refcnt=5
    pending: hci_cmd_timeout
    inactive: hci_conn_timeout
workqueue hci1: flags=0xa0012
  pwq 5: cpus=0-1 node=0 flags=0x4 nice=-20 active=1/1 refcnt=5
    pending: hci_cmd_timeout
    inactive: hci_conn_timeout
workqueue hci2: flags=0xa0012
  pwq 5: cpus=0-1 node=0 flags=0x4 nice=-20 active=1/1 refcnt=5
    pending: hci_cmd_timeout
    inactive: hci_conn_timeout
workqueue hci3: flags=0xa0012
  pwq 5: cpus=0-1 node=0 flags=0x4 nice=-20 active=1/1 refcnt=5
    pending: hci_cmd_timeout
    inactive: hci_conn_timeout
pool 0: cpus=0 node=0 flags=0x0 nice=0 hung=202s workers=4 idle: 5797 1188 9
Showing backtraces of running workers in stalled CPU-bound worker pools:
pool 0:
task:kworker/0:0     state:R  running task     stack:24760 pid:8     ppid:2      flags:0x00004000
Workqueue: events request_firmware_work_func
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 schedule+0xbd/0x170 kernel/sched/core.c:6773
 schedule_timeout+0x160/0x280 kernel/time/timer.c:2167
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common kernel/sched/completion.c:116 [inline]
 wait_for_common kernel/sched/completion.c:127 [inline]
 wait_for_completion_killable_timeout+0x34f/0x610 kernel/sched/completion.c:288
 __fw_state_wait_common drivers/base/firmware_loader/firmware.h:103 [inline]
 fw_sysfs_wait_timeout drivers/base/firmware_loader/fallback.c:44 [inline]
 fw_load_sysfs_fallback drivers/base/firmware_loader/fallback.c:106 [inline]
 fw_load_from_user_helper drivers/base/firmware_loader/fallback.c:158 [inline]
 firmware_fallback_sysfs+0x4b7/0x940 drivers/base/firmware_loader/fallback.c:234
 _request_firmware+0xed9/0x1510 drivers/base/firmware_loader/main.c:936
 request_firmware_work_func+0xb0/0x1b0 drivers/base/firmware_loader/main.c:1189
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 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>

Crashes (21):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/18 18:47 linux-6.6.y 0bbbd97a442d 1c8c8cd8 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan BUG: workqueue lockup
2025/07/12 22:51 linux-6.6.y 59a2de10b81a 3cda49cf .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan BUG: workqueue lockup
2025/11/09 11:36 linux-6.6.y 0a805b6ea8cd 4e1406b4 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan BUG: workqueue lockup
2025/09/03 17:19 linux-6.6.y cc1a1c5b404a 96a211bc .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan BUG: workqueue lockup
2025/09/01 05:11 linux-6.6.y cc1a1c5b404a 807a3b61 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan BUG: workqueue lockup
2025/11/17 18:46 linux-6.6.y 0a805b6ea8cd ef766cd7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan BUG: workqueue lockup
2025/10/15 00:09 linux-6.6.y 655054d2c3c1 b6605ba8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan BUG: workqueue lockup
2025/10/13 17:52 linux-6.6.y 655054d2c3c1 b6605ba8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan BUG: workqueue lockup
2025/10/09 09:50 linux-6.6.y e617101e5626 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan BUG: workqueue lockup
2025/10/07 14:14 linux-6.6.y e617101e5626 8ef35d49 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan BUG: workqueue lockup
2025/09/30 03:20 linux-6.6.y 147338df3487 86341da6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan BUG: workqueue lockup
2025/09/14 18:46 linux-6.6.y 60a9e718726f e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan BUG: workqueue lockup
2025/09/11 02:15 linux-6.6.y fe9731e10004 fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan BUG: workqueue lockup
2025/08/15 23:23 linux-6.6.y bb9c90ab9c5a 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan BUG: workqueue lockup
2025/08/06 05:29 linux-6.6.y 3a8ababb8b6a ffe1dd46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan BUG: workqueue lockup
2025/08/01 00:49 linux-6.6.y dbcb8d8e4163 0c075d67 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan BUG: workqueue lockup
2025/07/06 13:23 linux-6.6.y a5df3a702b2c 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan BUG: workqueue lockup
2025/07/05 19:55 linux-6.6.y 3f5b4c104b7d 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan BUG: workqueue lockup
2025/06/24 10:05 linux-6.6.y 6282921b6825 e2f27c35 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan BUG: workqueue lockup
2025/06/24 01:18 linux-6.6.y 6282921b6825 e2f27c35 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan BUG: workqueue lockup
2025/06/17 05:08 linux-6.6.y c2603c511feb cfebc887 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan BUG: workqueue lockup
* Struck through repros no longer work on HEAD.