[syzbot] [wireless?] BUG: workqueue lockup in reg_todo
From: syzbot <hidden>
Date: 2026-09-23 07:59:30
Also in:
linux-wireless, lkml
Hello, syzbot found the following issue on: HEAD commit: 38872197cae2 Merge branch 'for-next/fixes' into for-kernelci git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci console output: https://syzkaller.appspot.com/x/log.txt?x=17105405580000 kernel config: https://syzkaller.appspot.com/x/.config?x=56ed23170c168d4c dashboard link: https://syzkaller.appspot.com/bug?extid=b733a65a200ab7aa2cbe compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 userspace arch: arm64 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/c5963fdd6790/disk-38872197.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/a8c2cab00c45/vmlinux-38872197.xz kernel image: https://storage.googleapis.com/syzbot-assets/bde15d173380/Image-38872197.gz.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+b733a65a200ab7aa2cbe@syzkaller.appspotmail.com sched: DL replenish lagged too much BUG: workqueue lockup - pool cpus=0 node=0 flags=0x0 nice=0 stuck for 35s! Showing busy workqueues and worker pools: workqueue events: flags=0x100 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=18 refcnt=19 in-flight: 9:reg_todo for 39s pending: 2*psi_avgs_work, 6*nsim_dev_hwstats_traffic_work, free_obj_work, 3*psi_avgs_work, delayed_vfree_work, vmstat_shepherd, 3*ovs_dp_masks_rebalance pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=9 refcnt=10 pending: 4*nsim_dev_hwstats_traffic_work, 4*ovs_dp_masks_rebalance, psi_avgs_work workqueue events_unbound: flags=0x2 pwq 8: cpus=0-1 flags=0x4 nice=0 active=9 refcnt=10 in-flight: 237:cfg80211_wiphy_work for 62s cfg80211_wiphy_work ,14:nsim_dev_trap_report_work for 14s ,6551:cfg80211_wiphy_work for 65s cfg80211_wiphy_work ,6553:cfg80211_wiphy_work for 10s ,6550:nsim_dev_trap_report_work for 7s pending: 2*nsim_dev_trap_report_work pwq 8: cpus=0-1 flags=0x4 nice=0 active=12 refcnt=13 in-flight: 6552:nsim_dev_trap_report_work for 9s ,40:cfg80211_wiphy_work for 59s cfg80211_wiphy_work ,3416:cfg80211_wiphy_work for 59s cfg80211_wiphy_work ,3118:cfg80211_wiphy_work for 2s ,6548:toggle_allocation_gate for 8s ,524:cfg80211_wiphy_work for 17s ,6554:nsim_dev_trap_report_work for 4s pending: 3*nsim_dev_trap_report_work workqueue events_power_efficient: flags=0x82 pwq 8: cpus=0-1 flags=0x4 nice=0 active=4 refcnt=5 in-flight: 5258:reg_check_chans_work for 9s ,373:neigh_periodic_work for 30s ,49:wg_ratelimiter_gc_entries for 1s pending: neigh_periodic_work pwq 8: cpus=0-1 flags=0x4 nice=0 active=2 refcnt=3 in-flight: 6555:gc_worker for 8s ,6549:hash_ipportnet6_gc for 4s workqueue events_dfl_long: flags=0x2 pwq 8: cpus=0-1 flags=0x4 nice=0 active=7 refcnt=8 pending: 7*defense_work_handler pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 in-flight: 5257:defense_work_handler for 8s workqueue netns: flags=0x6000a pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=5 in-flight: 5259:cleanup_net for 74s inactive: cleanup_net workqueue mm_percpu_wq: flags=0x108 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: vmstat_update pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: vmstat_update workqueue writeback: flags=0x4a pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 in-flight: 289:wb_workfn for 64s workqueue ipv6_addrconf: flags=0x6000a pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=7 in-flight: 134:addrconf_dad_work for 39s inactive: 3*addrconf_dad_work workqueue bat_events: flags=0x6000a pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=51 in-flight: 6547:batadv_tt_purge for 11s inactive: 2*batadv_tt_purge, batadv_bla_periodic_work, batadv_dat_purge, batadv_tt_purge, batadv_bla_periodic_work, batadv_dat_purge, batadv_bla_periodic_work, batadv_dat_purge, batadv_mcast_mla_update, 2*batadv_tt_purge, batadv_dat_purge, batadv_bla_periodic_work, batadv_dat_purge, batadv_bla_periodic_work, batadv_mcast_mla_update, batadv_bla_periodic_work, batadv_dat_purge, 4*batadv_mcast_mla_update, 5*batadv_iv_send_outstanding_bat_ogm_packet, 3*batadv_purge_orig, batadv_iv_send_outstanding_bat_ogm_packet, 3*batadv_purge_orig, 12*batadv_iv_send_outstanding_bat_ogm_packet workqueue wg-crypt-wg0: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=2 refcnt=3 pending: wg_packet_encrypt_worker, wg_packet_tx_worker pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-crypt-wg1: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-kex-wg0: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 in-flight: 6546:wg_packet_handshake_send_worker for 0s workqueue wg-crypt-wg0: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=2 refcnt=3 pending: wg_packet_tx_worker, wg_packet_encrypt_worker workqueue wg-crypt-wg2: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=2 refcnt=3 pending: wg_packet_encrypt_worker, wg_packet_tx_worker workqueue wg-crypt-wg1: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=2 refcnt=3 pending: wg_packet_encrypt_worker, wg_packet_tx_worker workqueue wg-crypt-wg2: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=2 refcnt=3 pending: wg_packet_encrypt_worker, wg_packet_tx_worker workqueue wg-kex-wg0: flags=0x124 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_receive_worker workqueue wg-crypt-wg0: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=3 refcnt=4 pending: wg_packet_tx_worker, wg_packet_encrypt_worker, wg_packet_decrypt_worker workqueue wg-kex-wg2: flags=0x124 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_receive_worker workqueue wg-crypt-wg2: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-crypt-wg0: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=3 refcnt=4 pending: wg_packet_encrypt_worker, wg_packet_tx_worker, wg_packet_decrypt_worker pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-kex-wg1: flags=0x124 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_receive_worker workqueue wg-crypt-wg1: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=3 refcnt=4 pending: wg_packet_decrypt_worker, wg_packet_encrypt_worker, wg_packet_tx_worker workqueue wg-kex-wg2: flags=0x124 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_receive_worker workqueue wg-crypt-wg2: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=2 refcnt=3 pending: wg_packet_encrypt_worker, wg_packet_tx_worker workqueue wg-crypt-wg0: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=3 refcnt=4 pending: wg_packet_encrypt_worker, wg_packet_tx_worker, wg_packet_decrypt_worker workqueue wg-crypt-wg1: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=3 refcnt=4 pending: wg_packet_decrypt_worker, wg_packet_encrypt_worker, wg_packet_tx_worker workqueue wg-crypt-wg2: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=2 refcnt=3 pending: wg_packet_tx_worker, wg_packet_encrypt_worker workqueue wg-crypt-wg0: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=3 refcnt=4 pending: wg_packet_encrypt_worker, wg_packet_tx_worker, wg_packet_decrypt_worker workqueue wg-kex-wg1: flags=0x124 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_receive_worker workqueue wg-crypt-wg1: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=3 refcnt=4 pending: wg_packet_decrypt_worker, wg_packet_encrypt_worker, wg_packet_tx_worker workqueue wg-kex-wg2: flags=0x124 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_receive_worker workqueue wg-kex-wg2: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 in-flight: 394:wg_packet_handshake_send_worker for 3s workqueue wg-crypt-wg2: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=3 refcnt=4 pending: wg_packet_decrypt_worker, wg_packet_encrypt_worker, wg_packet_tx_worker pool 2: cpus=0 node=0 flags=0x0 nice=0 hung=35s workers=7 idle: 4802 4872 10 4820 870 4902 pool 8: cpus=0-1 flags=0x4 nice=0 hung=0s workers=25 idle: 12 Showing backtraces of busy workers in stalled worker pools: pool 2: task:kworker/0:0 state:R running task stack:0 pid:9 tgid:9 ppid:2 task_flags:0x4208060 flags:0x00000010 Workqueue: events reg_todo Call trace: __switch_to+0x2b4/0x6e4 arch/arm64/kernel/process.c:775 (T) context_switch kernel/sched/core.c:5526 [inline] __schedule+0x1370/0x2d80 kernel/sched/core.c:7277 preempt_schedule_common+0xd4/0x190 kernel/sched/core.c:7456 preempt_schedule+0x60/0x78 kernel/sched/core.c:7480 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:211 [inline] _raw_spin_unlock_irqrestore+0x94/0x98 kernel/locking/spinlock.c:221 spin_unlock_irqrestore include/linux/spinlock.h:425 [inline] __slab_free+0x194/0x1d0 mm/slub.c:5821 ___cache_free+0x80/0x94 mm/slub.c:6580 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0xb4/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x118/0x124 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x2c/0x88 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4683 [inline] slab_alloc_node mm/slub.c:4996 [inline] kmem_cache_alloc_noprof+0x268/0x5d4 mm/slub.c:5010 skb_clone+0x1ac/0x320 net/core/skbuff.c:2119 do_one_broadcast net/netlink/af_netlink.c:1456 [inline] netlink_broadcast_filtered+0x520/0xd58 net/netlink/af_netlink.c:1539 netlink_broadcast+0x50/0x68 net/netlink/af_netlink.c:1563 uevent_net_broadcast_untagged lib/kobject_uevent.c:331 [inline] kobject_uevent_net_broadcast+0x33c/0x53c lib/kobject_uevent.c:410 kobject_uevent_env+0x518/0x944 lib/kobject_uevent.c:611 call_crda net/wireless/reg.c:574 [inline] reg_query_database+0x278/0x4e4 net/wireless/reg.c:1116 reg_process_hint_core net/wireless/reg.c:2681 [inline] reg_process_hint+0x1b8/0x990 net/wireless/reg.c:3027 reg_process_pending_hints net/wireless/reg.c:3115 [inline] reg_todo+0x168/0x6a4 net/wireless/reg.c:3206 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0x91c/0x1250 kernel/workqueue.c:3479 worker_thread+0x798/0xbd0 kernel/workqueue.c:3560 kthread+0x304/0x3d4 kernel/kthread.c:436 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:838 --- This report is generated by a bot. 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