INFO: task syz-executor:2950 blocked for more than 143 seconds. Not tainted 6.16.0-rc7-syzkaller-g51d4b0a44c82 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:24520 pid:2950 tgid:2950 ppid:1 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x1325/0x3b10 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6879 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936 rwsem_down_read_slowpath+0x62f/0xb60 kernel/locking/rwsem.c:1084 __down_read_common kernel/locking/rwsem.c:1248 [inline] __down_read kernel/locking/rwsem.c:1261 [inline] down_read+0xef/0x480 kernel/locking/rwsem.c:1526 kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180 d_revalidate fs/namei.c:929 [inline] d_revalidate fs/namei.c:925 [inline] lookup_fast+0x266/0x610 fs/namei.c:1778 walk_component+0x5b/0x5b0 fs/namei.c:2134 link_path_walk+0x627/0xe20 fs/namei.c:2506 path_openat+0x1b0/0x2cb0 fs/namei.c:4051 do_filp_open+0x20b/0x470 fs/namei.c:4082 do_sys_openat2+0x11b/0x1d0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe78822e461 RSP: 002b:00007fffabc49840 EFLAGS: 00000287 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000481 RCX: 00007fe78822e461 RDX: 0000000000090800 RSI: 00007fe7882b2111 RDI: 00000000ffffff9c RBP: 00007fffabc498ec R08: 000000000002c270 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000287 R12: 000000000000019c R13: 0000000000000000 R14: 00000000000e6f85 R15: 00007fffabc49940 INFO: task syz-executor:2952 blocked for more than 144 seconds. Not tainted 6.16.0-rc7-syzkaller-g51d4b0a44c82 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:22680 pid:2952 tgid:2952 ppid:1 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x1325/0x3b10 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6879 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936 rwsem_down_read_slowpath+0x62f/0xb60 kernel/locking/rwsem.c:1084 __down_read_common kernel/locking/rwsem.c:1248 [inline] __down_read kernel/locking/rwsem.c:1261 [inline] down_read+0xef/0x480 kernel/locking/rwsem.c:1526 kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180 d_revalidate fs/namei.c:929 [inline] d_revalidate fs/namei.c:925 [inline] lookup_fast+0x266/0x610 fs/namei.c:1778 walk_component+0x5b/0x5b0 fs/namei.c:2134 link_path_walk+0x627/0xe20 fs/namei.c:2506 path_openat+0x1b0/0x2cb0 fs/namei.c:4051 do_filp_open+0x20b/0x470 fs/namei.c:4082 do_sys_openat2+0x11b/0x1d0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f737767e461 RSP: 002b:00007ffd96757290 EFLAGS: 00000287 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000000000000045d RCX: 00007f737767e461 RDX: 0000000000090800 RSI: 00007f7377702111 RDI: 00000000ffffff9c RBP: 00007ffd9675733c R08: 000000000002c14c R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000287 R12: 0000000000000188 R13: 0000000000000000 R14: 00000000000e6a65 R15: 00007ffd96757390 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff890c8440 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff890c8440 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff890c8440 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770 2 locks held by kworker/u8:2/38: 2 locks held by getty/2906: #0: ffff88811237a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000432f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/2950: #0: ffff888100ac4988 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1162 1 lock held by syz-executor/2952: #0: ffff888100ac4988 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1162 1 lock held by syz-executor/2954: #0: ffff888100ac4988 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1162 1 lock held by syz-executor/2956: #0: ffff888100ac4988 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1162 1 lock held by syz-executor/2957: #0: ffff888100ac4988 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1162 4 locks held by udevd/5230: #0: ffff8881335610a0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182 #1: ffff88811c26dc88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff8881199583c8 (kn->active#18){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff88811aa2c198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:889 [inline] #3: ffff88811aa2c198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 3 locks held by kworker/1:5/5304: 6 locks held by kworker/0:6/5918: 8 locks held by kworker/0:7/7353: 1 lock held by syz.1.2013/12464: #0: ffff888100ac4988 ( &root->kernfs_rwsem){++++}-{4:4} , at: kernfs_remove_by_name_ns+0x3d/0x110 fs/kernfs/dir.c:1712 1 lock held by syz.0.2020/12474: 1 lock held by syz-executor/12478: #0: ffff888100ac4988 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180 1 lock held by syz-executor/12480: #0: ffff888100ac4988 ( &root->kernfs_rwsem){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180 1 lock held by syz-executor/12481: #0: ffff888100ac4988 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180 1 lock held by syz-executor/12482: #0: ffff888100ac4988 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.16.0-rc7-syzkaller-g51d4b0a44c82 #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xf70/0x12c0 kernel/hung_task.c:470 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5b3/0x6c0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 7353 Comm: kworker/0:7 Not tainted 6.16.0-rc7-syzkaller-g51d4b0a44c82 #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events_power_efficient gc_worker RIP: 0010:io_serial_out+0x8f/0xb0 drivers/tty/serial/8250/8250_port.c:416 Code: 48 8d 7d 40 44 89 e1 48 b8 00 00 00 00 00 fc ff df 48 89 fa d3 e3 48 c1 ea 03 80 3c 02 00 75 1c 66 03 5d 40 44 89 e8 89 da ee <5b> 5d 41 5c 41 5d e9 46 87 5c 04 e8 c1 1e 05 ff eb a0 e8 4a 1f 05 RSP: 0018:ffffc90000007500 EFLAGS: 00000002 RAX: 000000000000005b RBX: 00000000000003f8 RCX: 0000000000000000 RDX: 00000000000003f8 RSI: ffffffff82d57865 RDI: ffffffff9392af80 RBP: ffffffff9392af40 R08: 0000000000000001 R09: 000000000000001f R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 000000000000005b R14: ffffffff9392af40 R15: ffffffff82d57800 FS: 0000000000000000(0000) GS:ffff888269160000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2c513ff8 CR3: 00000001241a2000 CR4: 00000000003506f0 Call Trace: serial_port_out include/linux/serial_core.h:798 [inline] serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3306 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3378 [inline] serial8250_console_write+0xfbc/0x1890 drivers/tty/serial/8250/8250_port.c:3456 console_emit_next_record kernel/printk/printk.c:3138 [inline] console_flush_all+0x801/0xc60 kernel/printk/printk.c:3226 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0xd8/0x210 kernel/printk/printk.c:3325 vprintk_emit+0x418/0x6d0 kernel/printk/printk.c:2450 dev_vprintk_emit drivers/base/core.c:4917 [inline] dev_printk_emit+0xfa/0x140 drivers/base/core.c:4928 __dev_printk+0xf5/0x270 drivers/base/core.c:4940 _dev_warn+0xe4/0x120 drivers/base/core.c:4984 usb_rx_callback_intf0+0x11c/0x1a0 drivers/media/rc/imon.c:1768 __usb_hcd_giveback_urb+0x38d/0x6e0 drivers/usb/core/hcd.c:1663 usb_hcd_giveback_urb+0x39b/0x450 drivers/usb/core/hcd.c:1747 dummy_timer+0x1814/0x3a30 drivers/usb/gadget/udc/dummy_hcd.c:1995 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x1ff/0xad0 kernel/time/hrtimer.c:1825 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1842 handle_softirqs+0x208/0x8d0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xfa/0x160 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5875 Code: 84 11 0b 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 72 7d 20 09 0f 82 74 02 00 00 8b 35 9a 8b 20 09 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 89 84 11 0b 0f 85 c7 02 00 00 48 83 c4 RSP: 0018:ffffc90014397ae0 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff890c8440 RCX: 00000000c724973b RDX: 0000000000000000 RSI: ffffffff88ae59a0 RDI: ffffffff87690bc0 RBP: 0000000000000002 R08: 00ee82d37f49bfc2 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] gc_worker+0x241/0x16d0 net/netfilter/nf_conntrack_core.c:1549 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5b3/0x6c0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245