INFO: task syz.2.141:6500 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.141 state:D stack:27720 pid:6500 tgid:6488 ppid:5827 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5254 [inline]
__schedule+0x17c4/0x4d60 kernel/sched/core.c:6862
__schedule_loop kernel/sched/core.c:6944 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6959
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7016
rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185
__down_write_common kernel/locking/rwsem.c:1317 [inline]
__down_write kernel/locking/rwsem.c:1326 [inline]
down_write_nested+0x1b5/0x200 kernel/locking/rwsem.c:1707
inode_lock_nested include/linux/fs.h:1108 [inline]
filename_create+0x1f8/0x3c0 fs/namei.c:4226
do_mkdirat+0xa0/0x590 fs/namei.c:4478
__do_sys_mkdirat fs/namei.c:4503 [inline]
__se_sys_mkdirat fs/namei.c:4501 [inline]
__x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4501
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7feea978efc9
RSP: 002b:00007feeaa58f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007feea99e6180 RCX: 00007feea978efc9
RDX: 0000000000000000 RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007feea9811f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007feea99e6218 R14: 00007feea99e6180 R15: 00007fff8994efe8
Showing all locks held in the system:
2 locks held by kworker/u8:1/13:
1 lock held by khungtaskd/31:
#0: ffffffff8df3d960 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df3d960 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8df3d960 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
5 locks held by kworker/0:2/798:
#0: ffff8880206acd48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x841/0x15d0 kernel/workqueue.c:3242
#1: ffffc90003577ba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x868/0x15d0 kernel/workqueue.c:3243
#2: ffff888028422198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#2: ffff888028422198 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4ef0 drivers/usb/core/hub.c:5899
#3: ffff88801f6b5198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#3: ffff88801f6b5198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1006
#4: ffff8880320b7160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#4: ffff8880320b7160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1006
2 locks held by kworker/u8:6/1158:
2 locks held by kworker/u8:7/1163:
#0: ffff88813fe69148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x841/0x15d0 kernel/workqueue.c:3242
#1: ffffc9000403fba0 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15d0 kernel/workqueue.c:3243
3 locks held by udevd/5197:
2 locks held by getty/5585:
#0: ffff888034a170a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1:
ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz-executor/5825:
#0: ffffffff8df433f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#0: ffffffff8df433f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957
2 locks held by udevd/5887:
2 locks held by syz.2.141/6499:
2 locks held by syz.2.141/6500:
#0: ffff88803263e420 (sb_writers#24){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:498
#1: ffff88805b6402a0 (&type->i_mutex_dir_key#15/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1108 [inline]
#1: ffff88805b6402a0 (&type->i_mutex_dir_key#15/1){+.+.}-{4:4}, at: filename_create+0x1f8/0x3c0 fs/namei.c:4226
1 lock held by syz.4.426/7605:
#0: ffffffff8df433f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#0: ffffffff8df433f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957
2 locks held by modprobe/7628:
#0: ffff8880b863a018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:646
#1: ffff8880b8724048 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:337 [inline]
watchdog+0xfa9/0xff0 kernel/hung_task.c:500
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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: 5825 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:__lock_acquire+0x2d/0xd20 kernel/locking/lockdep.c:5093
Code: 41 56 41 55 41 54 53 48 83 ec 30 48 89 fb 65 48 8b 3c 25 08 e0 73 92 45 31 ff 83 3d 6c e6 df 0d 00 0f 84 7e 0c 00 00 48 8b 03 <48> 3d 80 93 37 93 0f 84 6f 0c 00 00 41 89 cc 41 89 d6 8b 0d 9b 24
RSP: 0018:ffffc90000a08ab0 EFLAGS: 00000002
RAX: ffffffff99834b80 RBX: ffffffff8df3da80 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888027b43c80
RBP: ffffffff81a86d17 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1efae8f R12: 0000000000000002
R13: ffffffff8df3da80 R14: 0000000000000000 R15: 0000000000000000
FS: 000055556954d500(0000) GS:ffff888125fe2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcbffb212c0 CR3: 00000000684ee000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_do_batch kernel/rcu/tree.c:2599 [inline]
rcu_core+0xc54/0x1770 kernel/rcu/tree.c:2861
handle_softirqs+0x286/0x870 kernel/softirq.c:626
__do_softirq kernel/softirq.c:660 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:727
irq_exit_rcu+0x9/0x30 kernel/softirq.c:743
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2034 [inline]
RIP: 0010:vprintk_emit+0x49d/0x590 kernel/printk/printk.c:2422
Code: 0f 84 34 ff ff ff e8 42 f7 1f 00 fb eb 44 e8 3a f7 1f 00 e8 85 b3 b4 09 4d 85 f6 74 94 e8 2b f7 1f 00 fb 48 c7 c7 80 1a f3 8d <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 4b 2b
RSP: 0018:ffffc9000416f940 EFLAGS: 00000293
RAX: ffffffff81a08e95 RBX: ffffffff81a08cee RCX: ffff888027b43c80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8df31a80
RBP: ffffc9000416fa50 R08: ffffffff8f7d7477 R09: 1ffffffff1efae8e
R10: dffffc0000000000 R11: fffffbfff1efae8f R12: 0000000000000000
R13: 000000000000004c R14: 0000000000000200 R15: 1ffff9200082df2c
_printk+0xcf/0x120 kernel/printk/printk.c:2448
__ext4_msg+0x293/0x2a0 fs/ext4/super.c:990
ext4_put_super+0xb8/0xc40 fs/ext4/super.c:1295
generic_shutdown_super+0x135/0x2c0 fs/super.c:643
kill_block_super+0x44/0x90 fs/super.c:1723
ext4_kill_sb+0x68/0xb0 fs/ext4/super.c:7403
deactivate_locked_super+0xbc/0x130 fs/super.c:474
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1317
task_work_run+0x1d4/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xe9/0x130 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff7361902f7
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffcdba9e978 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007ff736211d7d RCX: 00007ff7361902f7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffcdba9ea30
RBP: 00007ffcdba9ea30 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffcdba9fac0
R13: 00007ff736211d7d R14: 000000000004bfc8 R15: 00007ffcdba9fb00