INFO: task syz.6.371:1068[ 461.897844][ T38] INFO: task syz.6.371:10684 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.371 state:D stack:25448 pid:10684 tgid:10682 ppid:8216 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x16dc/0x5500 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 io_schedule+0x80/0xe0 kernel/sched/core.c:8154 TXN_SLEEP_DROP_LOCK fs/jfs/jfs_txnmgr.c:125 [inline] txBegin+0x281/0xbe0 fs/jfs/jfs_txnmgr.c:376 jfs_rmdir+0x234/0x850 fs/jfs/namei.c:364 vfs_rmdir+0x3e9/0x6b0 fs/namei.c:5381 filename_rmdir+0x292/0x520 fs/namei.c:5438 __do_sys_rmdir fs/namei.c:5461 [inline] __se_sys_rmdir+0x2e/0x140 fs/namei.c:5458 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f51b07ede99 RSP: 002b:00007f51aea46028 EFLAGS: 00000246 ORIG_RAX: 0000000000000054 RAX: ffffffffffffffda RBX: 00007f51b0a75fa0 RCX: 00007f51b07ede99 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000380 RBP: 00007f51b0883eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f51b0a76038 R14: 00007f51b0a75fa0 R15: 00007ffd4c7d91a8 INFO: task syz.6.371:10697 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.371 state:D stack:28424 pid:10697 tgid:10682 ppid:8216 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x16dc/0x5500 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7607 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1670 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline] __rt_mutex_slowlock_locked+0x1f84/0x25b0 kernel/locking/rtmutex.c:1787 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1827 __rt_mutex_lock kernel/locking/rtmutex.c:1842 [inline] rwbase_write_lock+0x14c/0x720 kernel/locking/rwbase_rt.c:251 inode_lock include/linux/fs.h:1024 [inline] open_last_lookups fs/namei.c:4605 [inline] path_openat+0xae9/0x3850 fs/namei.c:4860 do_file_open+0x23e/0x4a0 fs/namei.c:4892 do_sys_openat2+0x115/0x200 fs/open.c:1368 do_sys_open fs/open.c:1374 [inline] __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1385 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f51b07ede99 RSP: 002b:00007f51aea25028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f51b0a76090 RCX: 00007f51b07ede99 RDX: 00000000001810c3 RSI: 0000200000000380 RDI: 0000000000000006 RBP: 00007f51b0883eaf R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000018e R11: 0000000000000246 R12: 0000000000000000 R13: 00007f51b0a76128 R14: 00007f51b0a76090 R15: 00007ffd4c7d91a8 Showing all locks held in the system: 4 locks held by pr/legacy/17: 1 lock held by khungtaskd/38: #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:3/55: #0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc9000121fc40 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc9000121fc40 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 6 locks held by kworker/u8:7/162: 5 locks held by kworker/u8:13/4200: #0: ffff88801aea0938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88801aea0938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc9000f7d7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc9000f7d7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8f5a2880 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:673 #3: ffff888025697160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline] #3: ffff888025697160 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline] #3: ffff888025697160 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x420 net/devlink/core.c:557 #4: ffff88803b126310 (&devlink->lock_key#12){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:292 [inline] #4: ffff88803b126310 (&devlink->lock_key#12){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline] #4: ffff88803b126310 (&devlink->lock_key#12){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x142/0x420 net/devlink/core.c:557 1 lock held by dhcpcd/5257: 2 locks held by getty/5351: #0: ffff888035f7d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211 2 locks held by udevd/5791: 3 locks held by syz.6.371/10684: #0: ffff888039210500 (sb_writers#27){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:494 #1: ffff888063384950 (&type->i_mutex_dir_key#18/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline] #1: ffff888063384950 (&type->i_mutex_dir_key#18/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2918 [inline] #1: ffff888063384950 (&type->i_mutex_dir_key#18/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2942 [inline] #1: ffff888063384950 (&type->i_mutex_dir_key#18/1){+.+.}-{4:4}, at: filename_rmdir+0x1cd/0x520 fs/namei.c:5431 #2: ffff8880633cc950 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #2: ffff8880633cc950 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: vfs_rmdir+0xf8/0x6b0 fs/namei.c:5366 2 locks held by syz.6.371/10697: #0: ffff888039210500 (sb_writers#27){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:494 #1: ffff888063384950 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #1: ffff888063384950 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: open_last_lookups fs/namei.c:4605 [inline] #1: ffff888063384950 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: path_openat+0xae9/0x3850 fs/namei.c:4860 8 locks held by syz-executor/11244: 10 locks held by syz-executor/11823: 1 lock held by syz-executor/14037: #0: ffffffff8f5b1438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f5b1438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f5b1438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158 2 locks held by syz-executor/14493: #0: ffffffff8fb15518 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8fb15518 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8fb15518 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f5b1438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f5b1438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f5b1438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158 2 locks held by kworker/u8:16/14700: #0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90005687c40 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90005687c40 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 3 locks held by syz-executor/14881: #0: ffffffff8fafa868 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8fafa868 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8fafa868 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f5b1438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f5b1438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f5b1438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158 #2: ffffffff8e061bb8 (wq_pool_mutex){+.+.}-{4:4}, at: __alloc_workqueue+0xa9c/0x2060 kernel/workqueue.c:5895 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 17 Comm: pr/legacy Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:401 Code: e8 8e ef 6f fc 44 89 f9 d3 e3 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 ff 60 d9 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07 RSP: 0018:ffffc90000167a28 EFLAGS: 00000202 RAX: 1ffffffff33c8b00 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff855548b0 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff99e45d40 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125c46000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f61493456b8 CR3: 000000000dfb0000 CR4: 00000000003526f0 Call Trace: serial_in drivers/tty/serial/8250/8250.h:128 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline] wait_for_lsr+0x190/0x300 drivers/tty/serial/8250/8250_port.c:1982 serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3235 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3318 [inline] serial8250_console_write+0x12a2/0x1b40 drivers/tty/serial/8250/8250_port.c:3385 console_emit_next_record kernel/printk/printk.c:3163 [inline] console_flush_one_record+0x642/0xb50 kernel/printk/printk.c:3269 legacy_kthread_func+0x1b6/0x250 kernel/printk/printk.c:3712 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245