INFO: task syz.0.2309:11283 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.0.2309 state:D stack:28328 pid:11283 tgid:11282 ppid:5847 task_flags:0x400040 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
blkdev_open+0x3a8/0x510 block/fops.c:676
do_dentry_open+0x953/0x13f0 fs/open.c:965
vfs_open+0x3b/0x340 fs/open.c:1095
do_open fs/namei.c:3887 [inline]
path_openat+0x2ee5/0x3830 fs/namei.c:4046
do_filp_open+0x1fa/0x410 fs/namei.c:4073
do_sys_openat2+0x121/0x1c0 fs/open.c:1435
do_sys_open fs/open.c:1450 [inline]
__do_sys_openat fs/open.c:1466 [inline]
__se_sys_openat fs/open.c:1461 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1461
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: 0033:0x7fbb88b8d290
RSP: 002b:00007fbb89a74b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000080200 RCX: 00007fbb88b8d290
RDX: 0000000000080200 RSI: 00007fbb89a74c10 RDI: 00000000ffffff9c
RBP: 00007fbb89a74c10 R08: 0000000000000000 R09: 002364626e2f7665
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 0000000000000001 R14: 00007fbb88db5fa0 R15: 00007ffd9e4b8f58
Showing all locks held in the system:
4 locks held by kworker/u8:1/13:
#0: ffff88801b6fe948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#0: ffff88801b6fe948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322
#1: ffffc90000127bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3215 [inline]
#1: ffffc90000127bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3322
#2: ffffffff8f92b850 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:658
#3: ffffffff8e5447f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#3: ffffffff8e5447f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:967
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 kworker/u8:10/3509:
2 locks held by getty/5612:
#0: ffff8880341bf0a0 (&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 udevd/6332:
#0: ffff888142fe7358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
1 lock held by syz.0.2309/11283:
#0: ffff888142fe7358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
3 locks held by syz.6.3416/14095:
=============================================
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: 14095 Comm: syz.6.3416 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:seqcount_lockdep_reader_access+0x57/0x180 include/linux/seqlock.h:67
Code: c7 04 24 b3 8a b5 41 48 c7 44 24 08 7e 9a e6 8d 48 c7 44 24 10 70 68 18 82 49 89 e7 49 c1 ef 03 48 b8 f1 f1 f1 f1 00 f2 f2 f2 <49> bc 00 00 00 00 00 fc ff df 4b 89 04 27 66 43 c7 44 27 09 f3 f3
RSP: 0018:ffffc900038c7600 EFLAGS: 00000806
RAX: f2f2f200f1f1f1f1 RBX: ffff88813fffbc50 RCX: dffffc0000000000
RDX: ffff88813fffbb80 RSI: ffffea000138f7c0 RDI: ffff88813fffbc50
RBP: ffffc900038c76a8 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1fc77e7 R12: 1ffff11027fff78a
R13: ffff88813fffbc20 R14: ffffea000138f7c0 R15: 1ffff92000718ec0
FS: 0000000000000000(0000) GS:ffff8881258b4000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055749f6a7000 CR3: 0000000030b9e000 CR4: 00000000003526f0
Call Trace:
read_seqbegin include/linux/seqlock.h:836 [inline]
zone_span_seqbegin include/linux/memory_hotplug.h:103 [inline]
page_outside_zone_boundaries mm/page_alloc.c:586 [inline]
bad_range+0x8b/0x2c0 mm/page_alloc.c:605
__free_one_page+0xf4/0xbd0 mm/page_alloc.c:957
free_pcppages_bulk+0x2da/0x4e0 mm/page_alloc.c:1488
free_frozen_page_commit+0x62c/0x1070 mm/page_alloc.c:2869
__free_frozen_pages+0x67f/0xd30 mm/page_alloc.c:2923
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: 0033:0x7f6f361c11e5
Code: Unable to access opcode bytes at 0x7f6f361c11bb.
RSP: 002b:00007f6f37013f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007f6f363b5fa0 RCX: 00007f6f361c11e5
RDX: 00007f6f37013fc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f6f36210b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f6f363b5fa0 R15: 00007ffdd96882c8