INFO: task udevd:5196 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:22216 pid:5196 tgid:5196 ppid:1 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5262 [inline] __schedule+0x1836/0x4ed0 kernel/sched/core.c:6870 __schedule_loop kernel/sched/core.c:6952 [inline] schedule+0x165/0x360 kernel/sched/core.c:6967 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7024 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 bdev_open+0xe0/0xd30 block/bdev.c:962 blkdev_open+0x457/0x600 block/fops.c:702 do_dentry_open+0x7e4/0x1430 fs/open.c:962 vfs_open+0x3b/0x340 fs/open.c:1094 do_open fs/namei.c:4014 [inline] path_openat+0x2efb/0x3860 fs/namei.c:4173 do_filp_open+0x1fa/0x410 fs/namei.c:4200 do_sys_openat2+0x121/0x1c0 fs/open.c:1434 do_sys_open fs/open.c:1449 [inline] __do_sys_openat fs/open.c:1465 [inline] __se_sys_openat fs/open.c:1460 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1460 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7205ca7407 RSP: 002b:00007fff70f9c750 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f720637c880 RCX: 00007f7205ca7407 RDX: 00000000000a0800 RSI: 00005578208252d0 RDI: ffffffffffffff9c RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 00005578173cf100 R14: 0000000000000000 R15: 00007fff70f9c9e0 INFO: task syz.2.444:7666 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.444 state:D stack:28296 pid:7666 tgid:7664 ppid:5832 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5262 [inline] __schedule+0x1836/0x4ed0 kernel/sched/core.c:6870 __schedule_loop kernel/sched/core.c:6952 [inline] schedule+0x165/0x360 kernel/sched/core.c:6967 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7024 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 bdev_release+0x1a9/0x650 block/bdev.c:1145 blkdev_release+0x15/0x20 block/fops.c:710 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:44 [inline] exit_to_user_mode_loop+0xff/0x4f0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2e9/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f43dd98f6c9 RSP: 002b:00007f43de8d2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007f43ddbe5fa0 RCX: 00007f43dd98f6c9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007f43dda11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f43ddbe6038 R14: 00007f43ddbe5fa0 R15: 00007ffe6802f2d8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e33d560 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e33d560 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e33d560 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:8/3547: #0: ffff88801badf148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x841/0x15e0 kernel/workqueue.c:3236 #1: ffffc9000bb97b80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x868/0x15e0 kernel/workqueue.c:3237 #2: ffffffff8e342f00 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3820 1 lock held by udevd/5196: #0: ffff888141fae358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962 1 lock held by udevd/5840: #0: ffff888141fae358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962 3 locks held by kworker/1:6/6997: #0: ffff88813fe55948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x841/0x15e0 kernel/workqueue.c:3236 #1: ffffc9000490fb80 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x868/0x15e0 kernel/workqueue.c:3237 #2: ffffffff8e343038 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #2: ffffffff8e343038 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957 1 lock held by syz.2.444/7666: #0: ffff888141fae358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1a9/0x650 block/bdev.c:1145 2 locks held by getty/8068: #0: ffff88814dcdc0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003efb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz.9.976/9206: 1 lock held by syz.8.1231/10116: 1 lock held by syz.5.1234/10125: #0: ffffffff8e343038 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8e343038 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:336 [inline] watchdog+0xfa8/0xff0 kernel/hung_task.c:499 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 1163 Comm: kworker/u8:7 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:hlock_class kernel/locking/lockdep.c:234 [inline] RIP: 0010:__lock_acquire+0xa4f/0xd20 kernel/locking/lockdep.c:5234 Code: e5 ff 90 0f 0b 90 90 90 31 c0 48 8b 3c 24 48 83 78 40 00 0f 84 8c 02 00 00 41 8b 46 20 25 ff 1f 00 00 48 0f a3 05 a1 ef 23 12 <73> 10 48 69 c0 c8 00 00 00 48 8d 80 70 53 63 93 eb 40 83 3d 28 7f RSP: 0018:ffffc90003b1f028 EFLAGS: 00000003 RAX: 0000000000000007 RBX: 0000000000000003 RCX: 00000000106bc235 RDX: 000000001595f31a RSI: 000000000678ecc1 RDI: ffff8880270e5b80 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff81741fd5 R10: ffffc90003b1f2d8 R11: fffff52000763e5d R12: 00000000d1e3f82a R13: ffff8880270e66b0 R14: ffff8880270e6728 R15: 9dbb69ff106bc235 FS: 0000000000000000(0000) GS:ffff888125b76000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2a6033 CR3: 000000007f67e000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x117/0x350 kernel/locking/lockdep.c:5868 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 __unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2539 [inline] slab_free mm/slub.c:6665 [inline] kfree+0x191/0x6e0 mm/slub.c:6873 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1576 [inline] ieee80211_ibss_rx_queued_mgmt+0x1206/0x2b10 net/mac80211/ibss.c:1602 ieee80211_iface_process_skb net/mac80211/iface.c:1736 [inline] ieee80211_iface_work+0x85f/0x12d0 net/mac80211/iface.c:1790 cfg80211_wiphy_work+0x2ab/0x470 net/wireless/core.c:438 process_one_work+0x93a/0x15e0 kernel/workqueue.c:3261 process_scheduled_works kernel/workqueue.c:3344 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245