INFO: task syz.0.1757:11633 blocked for more than 143 seconds.
Not tainted 6.16.0-rc6-next-20250714-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1757 state:D stack:27768 pid:11633 tgid:11632 ppid:5876 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5314 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6697
__schedule_loop kernel/sched/core.c:6775 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6790
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6847
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747
bdev_open+0xe0/0xd30 block/bdev.c:945
bdev_file_open_by_dev+0x1be/0x240 block/bdev.c:1059
setup_bdev_super+0x5a/0x5b0 fs/super.c:1599
get_tree_bdev_flags+0x366/0x4d0 fs/super.c:1679
vfs_get_tree+0x92/0x2b0 fs/super.c:1804
do_new_mount+0x2a2/0x9e0 fs/namespace.c:3805
do_mount fs/namespace.c:4133 [inline]
__do_sys_mount fs/namespace.c:4344 [inline]
__se_sys_mount+0x317/0x410 fs/namespace.c:4321
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5b3d38e929
RSP: 002b:00007f5b3e246038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f5b3d5b5fa0 RCX: 00007f5b3d38e929
RDX: 0000200000000180 RSI: 0000200000000a80 RDI: 0000200000000040
RBP: 00007f5b3d410b39 R08: 0000200000000140 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f5b3d5b5fa0 R15: 00007ffdcf0ed108
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e53eca0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e53eca0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e53eca0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by getty/5608:
#0: ffff8880338ae0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036c32f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by udevd/5888:
#0: ffff88802550b358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
3 locks held by kworker/1:5/5962:
#0: ffff88801a880d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#0: ffff88801a880d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322
#1: ffffc9000aabfbc0 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3215 [inline]
#1: ffffc9000aabfbc0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3322
#2: ffffffff8e5447f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#2: ffffffff8e5447f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:967
2 locks held by syz.0.1757/11633:
#0: ffff888028d080e0 (&type->s_umount_key#107/1){+.+.}-{4:4}, at: alloc_super+0x204/0x970 fs/super.c:345
#1: ffff88802550b358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
1 lock held by syz.2.2622/14758:
#0: ffffffff8e5447f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#0: ffffffff8e5447f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:967
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc6-next-20250714-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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:328 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:491
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
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: 14767 Comm: syz.3.2625 Not tainted 6.16.0-rc6-next-20250714-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:lockdep_recursion_inc kernel/locking/lockdep.c:468 [inline]
RIP: 0010:lock_release+0xbc/0x3e0 kernel/locking/lockdep.c:5891
Code: 40 73 aa 93 0f 84 11 02 00 00 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 48 8b 5c 24 20 fa 48 c7 c7 4d a1 c7 8d e8 b4 8c e0 09 <65> ff 05 9d ed 48 11 c7 44 24 20 01 00 00 00 83 3d ce dd 45 0e 00
RSP: 0018:ffffc90003227508 EFLAGS: 00000082
RAX: 0000000000000001 RBX: 0000000000000202 RCX: 3dd56cf5dc6bc200
RDX: 0000000000000000 RSI: ffffffff8dc7a14d RDI: ffffffff8c04dfc0
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff81cf0a36
R10: ffffc90003227658 R11: ffffffff81acd930 R12: 0000000000000004
R13: ffffffff81cf0a36 R14: ffffffff8e53eca0 R15: ffff88807c1b0000
FS: 0000000000000000(0000) GS:ffff8881258b4000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555765d73000 CR3: 000000007f0e0000 CR4: 00000000003526f0
Call Trace:
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
is_bpf_text_address+0x28d/0x2b0 kernel/bpf/core.c:778
kernel_text_address+0xa5/0xe0 kernel/extable.c:125
__kernel_text_address+0xd/0x40 kernel/extable.c:79
unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:369
arch_stack_walk+0xfc/0x150 arch/x86/kernel/stacktrace.c:26
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1395 [inline]
__free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895
vfree+0x25a/0x400 mm/vmalloc.c:3434
kcov_put kernel/kcov.c:439 [inline]
kcov_close+0x28/0x50 kernel/kcov.c:535
__fput+0x449/0xa70 fs/file_table.c:468
task_work_run+0x1d1/0x260 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x6b5/0x2300 kernel/exit.c:959
do_group_exit+0x21c/0x2d0 kernel/exit.c:1100
get_signal+0x1286/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:208 [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/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f90c5d8e929
Code: Unable to access opcode bytes at 0x7f90c5d8e8ff.
RSP: 002b:00007f90c6bd1038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: 0000200000000000 RBX: 00007f90c5fb5fa0 RCX: 00007f90c5d8e929
RDX: b635773f06ebbeef RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f90c5e10b39 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f90c5fb5fa0 R15: 00007ffff449c058