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: 49d, last: 4d09h
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 2087d 2493d 15/29 fixed on 2019/12/13 00:31
linux-5.15 BUG: workqueue lockup missing-backport origin:upstream -1 C done 624 21h40m 878d 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 3818 17h39m 774d 0/2 upstream: reported C repro on 2023/06/22 22:19
upstream BUG: workqueue lockup (2) -1 C 406 2643d 2801d 5/29 fixed on 2018/05/13 10:02
linux-4.14 BUG: workqueue lockup -1 C 282 888d 2289d 0/1 upstream: reported C repro on 2019/04/29 11:26
upstream BUG: workqueue lockup -1 C 172 2824d 2834d 3/29 fixed on 2017/11/11 01:37
upstream BUG: workqueue lockup (5) net 1 C done 13021 57m 2029d 0/29 upstream: reported C repro on 2020/01/14 22:04
android-5-10 BUG: workqueue lockup (2) -1 C error 9822 3h06m 883d 0/2 upstream: reported C repro on 2023/03/05 21:10
upstream BUG: workqueue lockup (3) -1 C 1215 2587d 2640d 8/29 fixed on 2018/07/09 18:05
android-6-1 BUG: workqueue lockup origin:upstream missing-backport -1 C error 3744 18h03m 743d 0/2 upstream: reported C repro on 2023/07/23 17:25
android-414 BUG: workqueue lockup -1 C 114 2152d 2308d 0/1 public: reported C repro on 2019/04/11 00:00
linux-4.19 BUG: workqueue lockup -1 C error 41 882d 2296d 0/1 upstream: reported C repro on 2019/04/22 20:37
android-5-10 BUG: workqueue lockup -1 C error 25 1282d 1380d 0/2 closed as invalid on 2022/02/22 17:18
android-49 BUG: workqueue lockup -1 C 69 2076d 2308d 0/3 public: reported C repro on 2019/04/11 08:44
android-6-12 BUG: workqueue lockup -1 1 17d 17d 0/1 premoderation: reported on 2025/07/18 16:39
linux-6.1 BUG: workqueue lockup origin:upstream missing-backport -1 C unreliable 317 1d21h 881d 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 159s!
Showing busy workqueues and worker pools:
workqueue events: flags=0x0
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=4/256 refcnt=5
    pending: 4*ovs_dp_masks_rebalance
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=3/256 refcnt=4
    pending: vmstat_shepherd, psi_avgs_work, ovs_dp_masks_rebalance
workqueue events_long: flags=0x0
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=2/256 refcnt=3
    pending: 2*defense_work_handler
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=3/256 refcnt=4
    pending: 3*defense_work_handler
workqueue events_unbound: flags=0x2
  pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/512 refcnt=2
    pending: toggle_allocation_gate
  pwq 4: cpus=0-1 flags=0x4 nice=0 active=2/512 refcnt=3
    pending: 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=5/256 refcnt=6
    pending: do_cache_clean, 2*neigh_managed_work, 2*neigh_periodic_work
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=3/256 refcnt=4
    pending: gc_worker, reg_check_chans_work, check_lifetime
workqueue rcu_gp: flags=0x8
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2
    pending: wait_rcu_exp_gp
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 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=0x40008
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/1 refcnt=2
    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
Showing backtraces of running workers in stalled CPU-bound worker pools:

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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
2025/08/01 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.