INFO: task udevd:5825 blocked for more than 144 seconds. Not tainted 6.14.0-rc4-syzkaller-00199-g76544811c850 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:S stack:23320 pid:5825 tgid:5825 ppid:5195 task_flags:0x400140 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x18bc/0x4c40 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6857 schedule_hrtimeout_range_clock+0x223/0x320 kernel/time/sleep_timeout.c:207 ep_poll fs/eventpoll.c:2099 [inline] do_epoll_wait+0x1db4/0x21c0 fs/eventpoll.c:2484 __do_sys_epoll_wait fs/eventpoll.c:2492 [inline] __se_sys_epoll_wait fs/eventpoll.c:2487 [inline] __x64_sys_epoll_wait+0x257/0x2a0 fs/eventpoll.c:2487 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbdbab23457 RSP: 002b:00007fffe181bb68 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fbdbab23457 RDX: 0000000000000004 RSI: 00007fffe181bba8 RDI: 0000000000000004 RBP: 0000556cdae09e80 R08: 0000000000000007 R09: 0a8bfe04823950d1 R10: 00000000ffffffff R11: 0000000000000246 R12: 0000556cdadf3860 R13: 00007fffe181bba8 R14: 0000000000000008 R15: 0000556cdade9910 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746 2 locks held by pvrusb2-context/2342: #0: ffff88807f3f0188 (&hdw->big_lock_mutex){+.+.}-{4:4}, at: pvr2_hdw_initialize+0xca/0x3d20 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2326 #1: ffffffff8e9e2f90 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0x140/0x300 kernel/umh.c:214 2 locks held by getty/5583: #0: ffff88814cea30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fd62f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x616/0x1770 drivers/tty/n_tty.c:2211 4 locks held by udevd/5842: #0: ffff88802c1202f0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb4/0xd70 fs/seq_file.c:182 #1: ffff88802a539488 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x53/0x3b0 fs/kernfs/file.c:154 #2: ffff8880346a65a8 (kn->active#22){.+.+}-{0:0}, at: kernfs_seq_start+0x72/0x3b0 fs/kernfs/file.c:155 #3: ffff88805cabc190 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1035 [inline] #3: ffff88805cabc190 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 6 locks held by kworker/1:7/5938: #0: ffff888021ae2d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff888021ae2d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319 #1: ffffc9000422fc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000422fc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319 #2: ffff888028a73190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline] #2: ffff888028a73190 (&dev->mutex){....}-{4:4}, at: hub_event+0x1fe/0x5150 drivers/usb/core/hub.c:5861 #3: ffff88805cabc190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline] #3: ffff88805cabc190 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x103/0x950 drivers/usb/core/hub.c:2307 #4: ffff88805b533160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline] #4: ffff88805b533160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #4: ffff88805b533160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1293 #5: ffff88807f3f0188 (&hdw->big_lock_mutex){+.+.}-{4:4}, at: pvr2_hdw_disconnect+0x6e/0x520 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2710 2 locks held by syz.2.541/8190: 4 locks held by syz.4.545/8205: #0: ffff88807cc240a0 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:289 [inline] #0: ffff88807cc240a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:335 [inline] #0: ffff88807cc240a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:366 [inline] #0: ffff88807cc240a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_release+0x5c/0x200 drivers/tty/tty_ldisc.c:780 #1: ffff88807cc260a0 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: __tty_ldisc_lock_nested drivers/tty/tty_ldisc.c:295 [inline] #1: ffff88807cc260a0 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:337 [inline] #1: ffff88807cc260a0 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:366 [inline] #1: ffff88807cc260a0 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_release+0x80/0x200 drivers/tty/tty_ldisc.c:780 #2: ffffffff8fec3088 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline] #2: ffffffff8fec3088 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x271/0x320 net/core/dev.c:2119 #3: ffffffff8eb3e478 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:334 [inline] #3: ffffffff8eb3e478 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x820 kernel/rcu/tree_exp.h:996 1 lock held by syz.3.551/8213: #0: ffffffff8eb3e340 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3741 1 lock held by dhcpcd/8242: #0: ffff88805c4f8e08 (&sb->s_type->i_mutex_key#9){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:877 [inline] #0: ffff88805c4f8e08 (&sb->s_type->i_mutex_key#9){+.+.}-{4:4}, at: __sock_release net/socket.c:646 [inline] #0: ffff88805c4f8e08 (&sb->s_type->i_mutex_key#9){+.+.}-{4:4}, at: sock_close+0x90/0x240 net/socket.c:1398 1 lock held by dhcpcd/8243: #0: ffff88805c4fe808 (&sb->s_type->i_mutex_key#9){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:877 [inline] #0: ffff88805c4fe808 (&sb->s_type->i_mutex_key#9){+.+.}-{4:4}, at: __sock_release net/socket.c:646 [inline] #0: ffff88805c4fe808 (&sb->s_type->i_mutex_key#9){+.+.}-{4:4}, at: sock_close+0x90/0x240 net/socket.c:1398 2 locks held by dhcpcd/8244: #0: ffff88805c4fca08 (&sb->s_type->i_mutex_key#9){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:877 [inline] #0: ffff88805c4fca08 (&sb->s_type->i_mutex_key#9){+.+.}-{4:4}, at: __sock_release net/socket.c:646 [inline] #0: ffff88805c4fca08 (&sb->s_type->i_mutex_key#9){+.+.}-{4:4}, at: sock_close+0x90/0x240 net/socket.c:1398 #1: ffffffff8eb3e478 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:334 [inline] #1: ffffffff8eb3e478 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x820 kernel/rcu/tree_exp.h:996 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc4-syzkaller-00199-g76544811c850 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:399 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 35 Comm: kworker/u8:2 Not tainted 6.14.0-rc4-syzkaller-00199-g76544811c850 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:87 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:104 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x86/0x290 mm/kasan/generic.c:189 Code: 00 fc ff df 4f 8d 3c 31 4c 89 fd 4c 29 dd 48 83 fd 10 7f 29 48 85 ed 0f 84 3e 01 00 00 4c 89 cd 48 f7 d5 48 01 dd 41 80 3b 00 <0f> 85 c9 01 00 00 49 ff c3 48 ff c5 75 ee e9 1e 01 00 00 45 89 dc RSP: 0018:ffffc90000ab7910 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 1ffffffff207786e RCX: ffffffff819cb224 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff903bc370 RBP: ffffffffffffffff R08: ffffffff903bc377 R09: 1ffffffff207786e R10: dffffc0000000000 R11: fffffbfff207786e R12: 1ffff92000156f30 R13: dffffc0000000000 R14: dffffc0000000001 R15: fffffbfff207786f FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000557090cd1028 CR3: 0000000034fd8000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] cpumask_test_cpu include/linux/cpumask.h:570 [inline] cpu_online include/linux/cpumask.h:1116 [inline] trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0xd4/0x550 kernel/locking/lockdep.c:5822 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xec/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd30 kernel/workqueue.c:3400 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244