INFO: task syz-executor:4192 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21968 pid: 4192 ppid: 1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 wb_wait_for_completion+0x171/0x290 fs/fs-writeback.c:191 sync_inodes_sb+0x1bd/0x950 fs/fs-writeback.c:2787 sync_filesystem+0x16d/0x220 fs/sync.c:64 generic_shutdown_super+0x6b/0x300 fs/super.c:448 kill_block_super+0x7c/0xe0 fs/super.c:1427 deactivate_locked_super+0x93/0xf0 fs/super.c:335 cleanup_mnt+0x42d/0x4e0 fs/namespace.c:1148 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fac59485897 RSP: 002b:00007fff2f571798 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fac59519ef0 RCX: 00007fac59485897 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff2f571850 RBP: 00007fff2f571850 R08: 00007fff2f572850 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff2f5728e0 R13: 00007fac59519ef0 R14: 0000000000010408 R15: 00007fff2f572920 Showing all locks held in the system: 4 locks held by kworker/u4:0/9: 1 lock held by khungtaskd/27: #0: ffffffff8c31eaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 4 locks held by kworker/u4:2/154: 4 locks held by kworker/u4:4/520: 2 locks held by kworker/0:2/2856: #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc9000cba7d00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 2 locks held by getty/3944: #0: ffff88814d4a3098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158 2 locks held by syz-executor/4183: #0: ffff88805c6280e0 (&type->s_umount_key#72 ){+.+.}-{3:3} , at: deactivate_super+0xa0/0xd0 fs/super.c:365 #1: ffff8881478227d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] ffff8881478227d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1a1/0x950 fs/fs-writeback.c:2785 2 locks held by syz-executor/4184: #0: ffff88807dbae0e0 ( &type->s_umount_key #72 ){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 #1: ffff8880205587d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1a1/0x950 fs/fs-writeback.c:2785 2 locks held by syz-executor/4185: #0: ffff88807847e0e0 (&type->s_umount_key#72){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 #1: ffff88814780c7d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] ffff88814780c7d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1a1/0x950 fs/fs-writeback.c:2785 2 locks held by syz-executor/4192: #0: ffff88807b9b40e0 ( &type->s_umount_key #72 ){+.+.}-{3:3} , at: deactivate_super+0xa0/0xd0 fs/super.c:365 #1: ffff88802055e7d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff88802055e7d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1a1/0x950 fs/fs-writeback.c:2785 3 locks held by kworker/0:3/4226: #0: ffff88802b21b538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc9000309fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffffffff8d43c848 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xca/0x1540 net/ipv6/addrconf.c:4110 4 locks held by kworker/u4:6/4312: 3 locks held by kworker/u4:8/4823: #0: ffff888016c79138 ( (wq_completion)events_unbound ){+.+.}-{0:0} , at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc900032dfd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffffffff8d43c848 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251 3 locks held by kworker/1:17/4880: #0: ffff88802b21b538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc9000350fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffff888079a6d240 ( &data->fib_lock ){+.+.}-{3:3}, at: nsim_fib_event_work+0x26a/0x33e0 drivers/net/netdevsim/fib.c:1480 3 locks held by syz-executor/6254: 2 locks held by dhcpcd/6513: #0: ffff888023364120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline] #0: ffff888023364120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xda0 net/packet/af_packet.c:3212 #1: ffffffff8c323528 ( rcu_state.exp_mutex ){+.+.}-{3:3} , at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] , at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845 2 locks held by dhcpcd/6515: #0: ffff88814c76c120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline] (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xda0 net/packet/af_packet.c:3212 #1: ffffffff8c323528 ( rcu_state.exp_mutex ){+.+.}-{3:3} , at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] , at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845 1 lock held by dhcpcd/6516: #0: ffff888054386120 ( sk_lock-AF_PACKET ){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline] ){+.+.}-{0:0}, at: packet_do_bind+0x35/0xda0 net/packet/af_packet.c:3212 1 lock held by dhcpcd/6517: #0: ffff888054384120 ( sk_lock-AF_PACKET ){+.+.}-{0:0} , at: lock_sock include/net/sock.h:1744 [inline] , at: packet_do_bind+0x35/0xda0 net/packet/af_packet.c:3212 1 lock held by dhcpcd/6518: #0: ffff88807d18e120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline] #0: ffff88807d18e120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xda0 net/packet/af_packet.c:3212 1 lock held by dhcpcd/6533: #0: ffff888053aaa120 (sk_lock-AF_PACKET){+.+.}-{0:0} , at: lock_sock include/net/sock.h:1744 [inline] , at: packet_do_bind+0x35/0xda0 net/packet/af_packet.c:3212 1 lock held by dhcpcd/6534: #0: ffff8880255f6120 (sk_lock-AF_PACKET){+.+.}-{0:0} , at: lock_sock include/net/sock.h:1744 [inline] , at: packet_do_bind+0x35/0xda0 net/packet/af_packet.c:3212 2 locks held by dhcpcd-run-hook/6540: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4970 Comm: kworker/u4:10 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:number+0xbac/0xf60 lib/vsprintf.c:560 Code: 08 72 0f e8 26 ed 71 fd 4d 85 ff 7f 5a e9 a6 00 00 00 bf 18 00 00 00 4c 89 fe e8 ef f0 71 fd 49 83 ff 17 77 59 e8 04 ed 71 fd <48> 8d 84 24 80 00 00 00 4a 8d 3c 38 48 89 f8 48 c1 e8 03 42 0f b6 RSP: 0018:ffffc90002f7f240 EFLAGS: 00000293 RAX: ffffffff8407353c RBX: 0000000000000032 RCX: ffff888029b73b80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000018 RBP: ffffc90002f7f360 R08: ffffc90002f7f2d7 R09: ffffc90002f7f2c0 R10: dffffc0000000000 R11: fffff520005efe5b R12: ffffc90002f7f645 R13: dffffc0000000000 R14: ffffc90002f7f645 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffeebda05c8 CR3: 000000002b08d000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vsnprintf+0x12d2/0x1c20 lib/vsprintf.c:2877 sprintf+0xe4/0x140 lib/vsprintf.c:3013 print_time kernel/printk/printk.c:1274 [inline] info_print_prefix+0x168/0x360 kernel/printk/printk.c:1300 record_print_text kernel/printk/printk.c:1349 [inline] console_unlock+0x66e/0x1120 kernel/printk/printk.c:2725 vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274 _printk+0xda/0x130 kernel/printk/printk.c:2299 ieee80211_sta_create_ibss+0x23e/0x450 net/mac80211/ibss.c:1344 ieee80211_sta_find_ibss net/mac80211/ibss.c:1481 [inline] ieee80211_ibss_work+0xdcc/0x10e0 net/mac80211/ibss.c:1710 cfg80211_wiphy_work+0x221/0x260 net/wireless/core.c:433 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287