INFO: task udevd:4899 blocked for more than 143 seconds. Not tainted 6.11.0-rc1-syzkaller-00033-g25f51b76f90f #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:24720 pid:4899 tgid:4899 ppid:2545 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xcda/0x2f80 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6621 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x5b8/0x9c0 kernel/locking/mutex.c:752 device_lock include/linux/device.h:1009 [inline] uevent_show+0x188/0x3b0 drivers/base/core.c:2743 dev_attr_show+0x53/0xe0 drivers/base/core.c:2437 sysfs_kf_seq_show+0x23e/0x410 fs/sysfs/file.c:59 seq_read_iter+0x4fa/0x12c0 fs/seq_file.c:230 kernfs_fop_read_iter+0x41a/0x590 fs/kernfs/file.c:279 new_sync_read fs/read_write.c:395 [inline] vfs_read+0x869/0xbd0 fs/read_write.c:476 ksys_read+0x12f/0x260 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa80b0ccb6a RSP: 002b:00007fff61d854b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000560fcce39520 RCX: 00007fa80b0ccb6a RDX: 0000000000001000 RSI: 0000560fcce34fb0 RDI: 0000000000000008 RBP: 0000560fcce39520 R08: 0000000000000008 R09: 0000000000000010 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000003fff R14: 00007fff61d85998 R15: 000000000000000a Showing all locks held in the system: 2 locks held by kworker/u8:1/28: #0: ffff888100089148 ( (wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1277/0x1b40 kernel/workqueue.c:3206 #1: ffffc900001e7d80 ((work_completion)(&pool->idle_cull_work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1b40 kernel/workqueue.c:3207 1 lock held by khungtaskd/30: #0: ffffffff88cb68a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #0: ffffffff88cb68a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff88cb68a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6620 5 locks held by kworker/1:1/37: #0: ffff888105297548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1277/0x1b40 kernel/workqueue.c:3206 #1: ffffc90000277d80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1b40 kernel/workqueue.c:3207 #2: ffff888106f7d190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #2: ffff888106f7d190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f50 drivers/usb/core/hub.c:5849 #3: ffff888120fc8190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #3: ffff888120fc8190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1004 #4: ffff888116853160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #4: ffff888116853160 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1004 2 locks held by getty/2603: #0: ffff888113d380a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000432f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc8/0x1490 drivers/tty/n_tty.c:2211 4 locks held by udevd/4899: #0: ffff8881017fa418 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xde/0x12c0 fs/seq_file.c:182 #1: ffff888104bd2888 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff888111de02d8 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff888115cc0190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #3: ffff888115cc0190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x188/0x3b0 drivers/base/core.c:2743 5 locks held by kworker/0:4/4921: 4 locks held by udevd/4930: #0: ffff88811b28b0a0 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xde/0x12c0 fs/seq_file.c:182 #1: ffff888117bafc88 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88811a4dca58 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffffffff88ce3088 (tk_core.seq.seqcount){----}-{0:0}, at: timekeeping_get_ns kernel/time/timekeeping.c:401 [inline] #3: ffffffff88ce3088 (tk_core.seq.seqcount){----}-{0:0}, at: ktime_get+0xd9/0x1a0 kernel/time/timekeeping.c:850 4 locks held by kworker/1:5/4973: 4 locks held by udevd/4984: #0: ffff88811bb80418 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xde/0x12c0 fs/seq_file.c:182 #1: ffff888104f08088 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88811a987b48 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff888120fc8190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #3: ffff888120fc8190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x188/0x3b0 drivers/base/core.c:2743 5 locks held by kworker/1:6/5690: 4 locks held by udevd/5961: #0: ffff8881219f3e80 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xde/0x12c0 fs/seq_file.c:182 #1: ffff88811d66c888 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88810e3d7968 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff88811726f190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #3: ffff88811726f190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x188/0x3b0 drivers/base/core.c:2743 1 lock held by syz.0.1590/10015: #0: ffffffff88cc2038 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock+0x282/0x3b0 kernel/rcu/tree_exp.h:296 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-rc1-syzkaller-00033-g25f51b76f90f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xf4e/0x1280 kernel/hung_task.c:379 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 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: 2534 Comm: klogd Not tainted 6.11.0-rc1-syzkaller-00033-g25f51b76f90f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 RIP: 0010:check_preemption_disabled+0x25/0xe0 lib/smp_processor_id.c:56 Code: 90 90 90 90 90 41 54 55 53 48 83 ec 08 65 8b 1d 0d ec 21 79 65 8b 05 02 ec 21 79 a9 ff ff ff 7f 74 0f 48 83 c4 08 89 d8 5b 5d <41> 5c c3 cc cc cc cc 9c 58 f6 c4 02 74 ea 65 48 8b 05 d5 eb 21 79 RSP: 0018:ffffc900016cf7e8 EFLAGS: 00000086 RAX: 0000000000000001 RBX: 1ffff920002d9f01 RCX: ffffc900016cf848 RDX: 1ffff11022abac31 RSI: ffffffff8727ea40 RDI: ffffffff87465d00 RBP: 403842e217768c85 R08: 0000000000000000 R09: fffffbfff1464bfb R10: ffffffff8a325fdf R11: 0000000000000000 R12: 0000000000000003 R13: 0000000000000004 R14: ffff8881155d6190 R15: ffff8881155d5700 FS: 00007f39ecade380(0000) GS:ffff8881f6300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f19e810b018 CR3: 00000001156f0000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:466 [inline] lock_release+0x3af/0x6f0 kernel/locking/lockdep.c:5782 rcu_lock_release include/linux/rcupdate.h:336 [inline] rcu_read_unlock include/linux/rcupdate.h:869 [inline] select_task_rq_fair+0x48c/0x3eb0 kernel/sched/fair.c:8251 select_task_rq kernel/sched/core.c:3437 [inline] try_to_wake_up+0x3db/0x10b0 kernel/sched/core.c:4152 autoremove_wake_function+0x16/0x150 kernel/sched/wait.c:384 receiver_wake_function+0x53/0x80 net/core/datagram.c:82 __wake_up_common+0x131/0x1e0 kernel/sched/wait.c:89 __wake_up_common_lock kernel/sched/wait.c:106 [inline] __wake_up_sync_key+0x36/0x50 kernel/sched/wait.c:173 sock_def_readable+0x160/0x610 net/core/sock.c:3374 unix_dgram_sendmsg+0xf62/0x19a0 net/unix/af_unix.c:2170 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x47f/0x4e0 net/socket.c:2204 __do_sys_sendto net/socket.c:2216 [inline] __se_sys_sendto net/socket.c:2212 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2212 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f39ecc409b5 Code: 8b 44 24 08 48 83 c4 28 48 98 c3 48 98 c3 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 26 45 31 c9 45 31 c0 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 7a 48 8b 15 44 c4 0c 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffe3ae47b68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f39ecc409b5 RDX: 000000000000004c RSI: 000055a0cea8b460 RDI: 0000000000000003 RBP: 000055a0cea812c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000013 R13: 00007f39ecdce212 R14: 00007ffe3ae47c68 R15: 0000000000000000