INFO: task udevd:16983 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd state:D stack:22360 pid:16983 tgid:16983 ppid:5202 task_flags:0x400140 flags:0x00080802
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x153e/0x4fe0 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7004
io_schedule+0x7f/0xd0 kernel/sched/core.c:7831
folio_wait_bit_common+0x6d8/0xbc0 mm/filemap.c:1323
folio_put_wait_locked mm/filemap.c:1487 [inline]
do_read_cache_folio+0x1ad/0x590 mm/filemap.c:4078
read_mapping_folio include/linux/pagemap.h:1028 [inline]
read_part_sector+0xb6/0x2b0 block/partitions/core.c:722
adfspart_check_POWERTEC+0x92/0xef0 block/partitions/acorn.c:454
check_partition block/partitions/core.c:141 [inline]
blk_add_partitions block/partitions/core.c:589 [inline]
bdev_disk_changed+0x765/0x14c0 block/partitions/core.c:693
blkdev_get_whole+0x380/0x510 block/bdev.c:765
bdev_open+0x31e/0xd30 block/bdev.c:974
blkdev_open+0x470/0x610 block/fops.c:698
do_dentry_open+0x785/0x14e0 fs/open.c:949
vfs_open+0x3b/0x340 fs/open.c:1081
do_open fs/namei.c:4671 [inline]
path_openat+0x2e08/0x3860 fs/namei.c:4830
do_file_open+0x23e/0x4a0 fs/namei.c:4859
do_sys_openat2+0x113/0x200 fs/open.c:1366
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1383
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2c458a7407
RSP: 002b:00007ffd80a4d800 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f2c45fbb880 RCX: 00007f2c458a7407
RDX: 00000000000a0800 RSI: 000055ffb525c430 RDI: ffffffffffffff9c
RBP: 000055ffb525b910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055ffb52826d0
R13: 000055ffb5269190 R14: 0000000000000000 R15: 000055ffb52826d0
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff8e75dfa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e75dfa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e75dfa0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by dhcpcd/5496:
#0: ffff8880b843abe0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:647
#1: ffff8880b8424588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
2 locks held by getty/14893:
#0: ffff888035ec30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000ff0b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
1 lock held by udevd/16983:
#0: ffff8880267c7358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962
4 locks held by udevd/21299:
#0: ffff888090261418 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:183
#1: ffff88807a20f088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172
#2: ffff8880255283c8 (kn->active#25){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff8880255283c8 (kn->active#25){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173
#3: ffff88803d79f198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:900 [inline]
#3: ffff88803d79f198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
7 locks held by kworker/1:2/9653:
#0: ffff88801e6c7548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x855/0x15a0 kernel/workqueue.c:3254
#1: ffffc9000fe1fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x87c/0x15a0 kernel/workqueue.c:3255
#2: ffff88802a467198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#2: ffff88802a467198 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899
#3: ffff88803d79f198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#3: ffff88803d79f198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1008
#4: ffff88807c94e160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#4: ffff88807c94e160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1008
#5: ffffffff8fbd5488 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#5: ffffffff8fbd5488 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2163
#6: ffffffff8e764238 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#6: ffffffff8e764238 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
1 lock held by syz.4.14824/16041:
#0: ffffffff8e764100 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
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:161 [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:346 [inline]
watchdog+0xf90/0xfe0 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 14695 Comm: kworker/u8:9 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:__this_cpu_preempt_check+0x0/0x20 lib/smp_processor_id.c:63
Code: 48 09 8c e8 32 f8 9e f5 e8 2d a3 aa f5 eb aa 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 89 fe 48 c7 c7 80 47 09 8c e9 fd fe ff ff cc cc cc
RSP: 0018:ffffc9000c8df468 EFLAGS: 00000046
RAX: 80c870f8a6f720be RBX: 0000000000000202 RCX: 0000000080000001
RDX: 0000000000000004 RSI: ffffffff8e75dfa0 RDI: ffffffff8e057ea5
RBP: ffff888028d4c840 R08: ffffc9000c8df908 R09: 0000000000000000
R10: ffffc9000c8df5f8 R11: fffff5200191bec1 R12: 0000000000000004
R13: 0000000000000004 R14: ffffffff8e75dfa0 R15: ffff888028d4bc80
FS: 0000000000000000(0000) GS:ffff8881253a3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc216d84fe0 CR3: 000000000e54a000 CR4: 00000000003526f0
Call Trace:
lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline]
lock_release+0x259/0x3a0 kernel/locking/lockdep.c:5891
rcu_lock_release include/linux/rcupdate.h:322 [inline]
rcu_read_unlock include/linux/rcupdate.h:881 [inline]
class_rcu_destructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0x1aaa/0x23c0 arch/x86/kernel/unwind_orc.c:695
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5129 [inline]
__kmalloc_node_track_caller_noprof+0x4db/0x7b0 mm/slub.c:5237
kmalloc_reserve+0x136/0x290 net/core/skbuff.c:625
__alloc_skb+0x1fd/0x710 net/core/skbuff.c:707
alloc_skb include/linux/skbuff.h:1383 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:819 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:876 [inline]
nsim_dev_trap_report_work+0x29a/0xb80 drivers/net/netdevsim/dev.c:922
process_one_work+0x949/0x15a0 kernel/workqueue.c:3279
process_scheduled_works kernel/workqueue.c:3362 [inline]
worker_thread+0x9af/0xee0 kernel/workqueue.c:3443
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245