INFO: task udevd:6114 blocked in I/O wait for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disabl[ 955.394734][ T38] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd state:D stack:22024 pid:6114 tgid:6114 ppid:5194 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x169e/0x54f0 kernel/sched/core.c:7188
__schedule_loop kernel/sched/core.c:7267 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7282
io_schedule+0x7f/0xd0 kernel/sched/core.c:8109
folio_wait_bit_common+0x6dd/0xbc0 mm/filemap.c:1323
folio_put_wait_locked mm/filemap.c:1492 [inline]
do_read_cache_folio+0x1a7/0x560 mm/filemap.c:4088
read_mapping_folio include/linux/pagemap.h:1017 [inline]
read_part_sector+0xb8/0x2b0 block/partitions/core.c:724
adfspart_check_POWERTEC+0x9a/0x7a0 block/partitions/acorn.c:450
check_partition block/partitions/core.c:143 [inline]
blk_add_partitions block/partitions/core.c:591 [inline]
bdev_disk_changed+0x817/0x1770 block/partitions/core.c:695
blkdev_get_whole+0x2e5/0x480 block/bdev.c:756
bdev_open+0x31e/0xcc0 block/bdev.c:965
blkdev_open+0x485/0x620 block/fops.c:697
do_dentry_open+0x83d/0x13e0 fs/open.c:947
vfs_open+0x3b/0x350 fs/open.c:1079
do_open fs/namei.c:4699 [inline]
path_openat+0x2e43/0x38a0 fs/namei.c:4858
do_file_open+0x23e/0x4a0 fs/namei.c:4887
do_sys_openat2+0x113/0x200 fs/open.c:1364
do_sys_open fs/open.c:1370 [inline]
__do_sys_openat fs/open.c:1386 [inline]
__se_sys_openat fs/open.c:1381 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1381
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbd543fa407
RSP: 002b:00007ffeade9b880 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fbd5430c880 RCX: 00007fbd543fa407
RDX: 00000000000a0800 RSI: 00005556e124e220 RDI: ffffffffffffff9c
RBP: 00005556e1246910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00005556e14f21c0
R13: 00005556e1254190 R14: 0000000000000000 R15: 00005556e14f21c0
INFO: task syz.3.2000:12855 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.2000 state:D stack:25216 pid:12855 tgid:12853 ppid:5826 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x169e/0x54f0 kernel/sched/core.c:7188
__schedule_loop kernel/sched/core.c:7267 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7563
rt_mutex_slowlock_block+0x508/0x680 kernel/locking/rtmutex.c:1659
__rt_mutex_slowlock kernel/locking/rtmutex.c:1736 [inline]
__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1776 [inline]
rt_mutex_slowlock+0x2dc/0x780 kernel/locking/rtmutex.c:1816
__rt_mutex_lock kernel/locking/rtmutex.c:1831 [inline]
__mutex_lock_common kernel/locking/rtmutex_api.c:535 [inline]
mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:553
sync_bdevs+0x27e/0x470 block/bdev.c:1296
ksys_sync fs/sync.c:105 [inline]
__ia32_sys_sync+0xc5/0x120 fs/sync.c:111
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe8f57fc819
RSP: 002b:00007fe8f3a35028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fe8f5a76090 RCX: 00007fe8f57fc819
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fe8f5a76090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe8f5a76128 R14: 00007fe8f5a76090 R15: 00007ffc4e7c93c8
Showing all locks held in the system:
1 lock held by khungtaskd/38:
#0: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6777
3 locks held by kworker/u8:10/1302:
#0: ffff88801a094138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3280 [inline]
#0: ffff88801a094138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa2e/0x1910 kernel/workqueue.c:3399
#1: ffffc900061ffc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3281 [inline]
#1: ffffc900061ffc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa69/0x1910 kernel/workqueue.c:3399
#2: ffffffff8f37f5f8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
4 locks held by kworker/u8:13/3076:
#0: ffff88801b296138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3280 [inline]
#0: ffff88801b296138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa2e/0x1910 kernel/workqueue.c:3399
#1: ffffc9000dc07c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3281 [inline]
#1: ffffc9000dc07c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa69/0x1910 kernel/workqueue.c:3399
#2: ffffffff8f370ce0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673
#3: ffffffff8f37f5f8 (rtnl_mutex){+.+.}-{4:4}, at: cfg80211_pernet_exit+0x19/0x120 net/wireless/core.c:1810
1 lock held by syslogd/5176:
#0: ffff888032b28e58 (&si->socket.wq.wait){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#0: ffff888032b28e58 (&si->socket.wq.wait){+.+.}-{3:3}, at: finish_wait+0xbe/0x1e0 kernel/sched/wait.c:394
2 locks held by klogd/5183:
#0: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: sock_def_readable+0xae/0x550 net/core/sock.c:3611
#1: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#1: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#1: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
#1: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57
2 locks held by dhcpcd/5489:
#0: ffff888057296928 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2404
#1: ffffffff8f37f5f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8f37f5f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6862
2 locks held by getty/5585:
#0: ffff8880372760a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003cbb2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211
1 lock held by udevd/6114:
#0: ffff888026ff14c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:953
7 locks held by kworker/0:7/12824:
#0: ffff888021ec9938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3280 [inline]
#0: ffff888021ec9938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa2e/0x1910 kernel/workqueue.c:3399
#1: ffffc90004227c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3281 [inline]
#1: ffffc90004227c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa69/0x1910 kernel/workqueue.c:3399
#2: ffff88802a50a210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#2: ffff88802a50a210 (&dev->mutex){....}-{4:4}, at: hub_event+0x17c/0x4f60 drivers/usb/core/hub.c:5899
#3: ffff8880393d2210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#3: ffff8880393d2210 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1076
#4: ffff888038dd11d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#4: ffff888038dd11d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1076
#5: ffffffff8ec21d00 (minor_rwsem#2){++++}-{4:4}, at: usb_register_dev+0x142/0x5f0 drivers/usb/core/file.c:134
#6: ffff88801b6e3238 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_activate fs/kernfs/dir.c:1463 [inline]
#6: ffff88801b6e3238 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_add_one+0x2ae/0x5c0 fs/kernfs/dir.c:869
1 lock held by syz.3.2000/12855:
#0: ffff888026ff14c8 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470 block/bdev.c:1296
4 locks held by syz-executor/13931:
#0: ffff888037a62480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2731 [inline]
#0: ffff888037a62480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684
#1: ffff88805af89078 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343
#2: ffff888027483b48 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888027483b48 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344
#3: ffffffff8ebe4318 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x13c/0x710 drivers/net/netdevsim/bus.c:184
10 locks held by syz-executor/13936:
#0: ffff888037a62480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2731 [inline]
#0: ffff888037a62480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684
#1: ffff88801af3b478 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343
#2: ffff888027483a58 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888027483a58 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344
#3: ffffffff8ebe4318 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234
#4: ffff88802a3e2160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#4: ffff88802a3e2160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1174 [inline]
#4: ffff88802a3e2160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x870 drivers/base/dd.c:1372
#5: ffff888058f4a310 (&devlink->lock_key#10){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1799
#6: ffffffff8f37f5f8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x13a/0x830 drivers/net/netdevsim/netdev.c:1185
#7: ffff88801b6e3348 (&root->kernfs_supers_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x3f/0x140 fs/kernfs/dir.c:1792
#8: ffff88801b6e3238 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x4e/0x140 fs/kernfs/dir.c:1793
#9: ffff88801b6e32c0 (&root->kernfs_iattr_rwsem){++++}-{4:4}, at: __kernfs_remove+0x174/0x8e0 fs/kernfs/dir.c:1559
1 lock held by syz-executor/14102:
#0: ffffffff8f37f5f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f37f5f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8f37f5f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4107
4 locks held by syz.2.2374/14221:
#0: ffff888033fb44b0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:592 [inline]
#0: ffff888033fb44b0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x194/0x9e0 mm/mmap.c:1284
#1: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#1: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#1: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x200 mm/pgtable-generic.c:290
#2: ffff88803f77bdd8 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#2: ffff88803f77bdd8 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:404
#3: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#3: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#3: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
#3: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
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+0xfd3/0x1030 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 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:401
Code: e8 fe 5e 88 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 af bc f1 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 0a 08 fd 05 cc 44 89 f9 80 e1 07
RSP: 0018:ffffc900001679d0 EFLAGS: 00000202
RAX: 1ffffffff337a000 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffffff99bd0370 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff853c3f50 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff99bd00e0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881260c0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff1612a8cf4 CR3: 000000000ddb6000 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+0x1aa/0x2f0 drivers/tty/serial/8250/8250_port.c:1970
serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3207 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3290 [inline]
serial8250_console_write+0x1391/0x1b90 drivers/tty/serial/8250/8250_port.c:3357
console_emit_next_record kernel/printk/printk.c:3163 [inline]
console_flush_one_record+0x68b/0xb90 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