INFO: task kworker/u8:8:5917 blocked for more than 144 seconds.
Not tainted 6.12.0-next-20241128-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:8 state:D stack:19832 pid:5917 tgid:5917 ppid:2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:2)
Call Trace:
context_switch kernel/sched/core.c:5369 [inline]
__schedule+0x1850/0x4c30 kernel/sched/core.c:6756
__schedule_loop kernel/sched/core.c:6833 [inline]
schedule+0x14b/0x320 kernel/sched/core.c:6848
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6905
__mutex_lock_common kernel/locking/mutex.c:665 [inline]
__mutex_lock+0x7e7/0xee0 kernel/locking/mutex.c:735
exfat_write_inode+0xe5/0x1a0 fs/exfat/inode.c:108
write_inode fs/fs-writeback.c:1525 [inline]
__writeback_single_inode+0x708/0x10d0 fs/fs-writeback.c:1745
writeback_sb_inodes+0x820/0x1360 fs/fs-writeback.c:1976
__writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2047
wb_writeback+0x427/0xb80 fs/fs-writeback.c:2158
wb_check_background_flush fs/fs-writeback.c:2228 [inline]
wb_do_writeback fs/fs-writeback.c:2316 [inline]
wb_workfn+0xc4b/0x1080 fs/fs-writeback.c:2343
process_one_work kernel/workqueue.c:3229 [inline]
process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310
worker_thread+0x870/0xd30 kernel/workqueue.c:3391
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Showing all locks held in the system:
5 locks held by kworker/u8:1/12:
#0: ffff88801baed948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
#0: ffff88801baed948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310
#1: ffffc90000117d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
#1: ffffc90000117d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310
#2: ffffffff8fca8510 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:586
#3: ffffffff8fcb4988 (rtnl_mutex){+.+.}-{4:4}, at: cleanup_net+0x6af/0xcc0 net/core/net_namespace.c:622
#4: ffffffff8e93d038 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline]
#4: ffffffff8e93d038 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976
1 lock held by khungtaskd/30:
#0: ffffffff8e937b20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
#0: ffffffff8e937b20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8e937b20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6744
2 locks held by getty/5589:
#0: ffff88814eeb00a0 (&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+0x6a6/0x1e00 drivers/tty/n_tty.c:2211
3 locks held by kworker/1:4/5884:
#0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
#0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310
#1: ffffc900040cfd00 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
#1: ffffc900040cfd00 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310
#2: ffffffff8e93cf00 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4565
4 locks held by kworker/u8:8/5917:
#0: ffff88801eae3148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
#0: ffff88801eae3148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310
#1: ffffc9000427fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
#1: ffffc9000427fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310
#2: ffff888032cf20e0 (&type->s_umount_key#74){.+.+}-{4:4}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562
#3: ffff88805ba040e8 (&sbi->s_lock){+.+.}-{4:4}, at: exfat_write_inode+0xe5/0x1a0 fs/exfat/inode.c:108
3 locks held by kworker/u8:9/5937:
3 locks held by syz-executor/10310:
2 locks held by kworker/u8:0/12561:
4 locks held by dhcpcd-run-hook/12569:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-next-20241128-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:234 [inline]
watchdog+0xff6/0x1040 kernel/hung_task.c:397
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 12 Comm: kworker/u8:1 Not tainted 6.12.0-next-20241128-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: netns cleanup_net
RIP: 0010:kasan_check_range+0x0/0x290 mm/kasan/generic.c:188
Code: c7 c6 a0 ba 07 8e e8 ff 89 e1 ff 90 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <66> 0f 1f 00 55 41 57 41 56 41 54 53 b0 01 48 85 f6 0f 84 a0 01 00
RSP: 0018:ffffc900001174d8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff817aaec4
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90199eb0
RBP: ffffc90000117640 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed100e31aa79 R12: 1ffff92000022ea4
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880718d53c0
FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f48896635e8 CR3: 0000000059ab4000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
instrument_atomic_read include/linux/instrumented.h:68 [inline]
_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
cpumask_test_cpu include/linux/cpumask.h:570 [inline]
cpu_online include/linux/cpumask.h:1117 [inline]
trace_lock_acquire include/trace/events/lock.h:24 [inline]
lock_acquire+0xd4/0x550 kernel/locking/lockdep.c:5820
rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
rcu_read_lock include/linux/rcupdate.h:849 [inline]
kernfs_should_drain_open_files+0x88/0x320 fs/kernfs/file.c:784
kernfs_drain+0x289/0x6d0 fs/kernfs/dir.c:494
__kernfs_remove+0x400/0x870 fs/kernfs/dir.c:1486
kernfs_remove+0x7a/0xa0 fs/kernfs/dir.c:1528
__kobject_del+0xe2/0x310 lib/kobject.c:604
kobject_del lib/kobject.c:627 [inline]
kset_unregister+0x50/0x80 lib/kobject.c:890
remove_queue_kobjects net/core/net-sysfs.c:1959 [inline]
netdev_unregister_kobject+0x169/0x250 net/core/net-sysfs.c:2107
unregister_netdevice_many_notify+0x1859/0x1da0 net/core/dev.c:11556
cleanup_net+0x75d/0xcc0 net/core/net_namespace.c:627
process_one_work kernel/workqueue.c:3229 [inline]
process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310
worker_thread+0x870/0xd30 kernel/workqueue.c:3391
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244