INFO: task kworker/u8:5:967 blocked for more than 143 seconds.
Not tainted 6.15.0-rc6-syzkaller-00208-g3c21441eeffc #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:5 state:D stack:22456 pid:967 tgid:967 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:5)
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x168f/0x4c70 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6860
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
__mutex_lock_common kernel/locking/mutex.c:678 [inline]
__mutex_lock+0x724/0xe80 kernel/locking/mutex.c:746
jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:102
jfs_write_inode+0x145/0x220 fs/jfs/inode.c:132
write_inode fs/fs-writeback.c:1525 [inline]
__writeback_single_inode+0x6ee/0xff0 fs/fs-writeback.c:1745
writeback_sb_inodes+0x6b5/0x1000 fs/fs-writeback.c:1976
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2047
wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2158
wb_check_old_data_flush fs/fs-writeback.c:2262 [inline]
wb_do_writeback fs/fs-writeback.c:2315 [inline]
wb_workfn+0xaef/0xef0 fs/fs-writeback.c:2343
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764
4 locks held by kworker/u8:5/967:
#0: ffff888020ad1948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff888020ad1948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc900038f7c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc900038f7c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
#2: ffff88804f83a0e0 (&type->s_umount_key#75){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562
#3: ffff88805ab48b00 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:102
2 locks held by getty/5579:
#0: ffff888034c2a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90002ffe2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
4 locks held by syz.5.467/10192:
2 locks held by syz.2.523/10729:
#0: ffff88804f83a0e0 (&type->s_umount_key#75){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88804f83a0e0 (&type->s_umount_key#75){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
#1: ffff888142fe07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
#1: ffff888142fe07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831
2 locks held by syz.7.697/12675:
2 locks held by syz.5.698/12682:
2 locks held by syz.1.699/12689:
#0: ffff8880b88399d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605
#1: ffff8880b8823b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987
3 locks held by dhcpcd-run-hook/12725:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc6-syzkaller-00208-g3c21441eeffc #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:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:437
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
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: 12729 Comm: syz.8.701 Not tainted 6.15.0-rc6-syzkaller-00208-g3c21441eeffc #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__min_vruntime_update kernel/sched/fair.c:809 [inline]
RIP: 0010:min_vruntime_update kernel/sched/fair.c:833 [inline]
RIP: 0010:min_vruntime_cb_propagate kernel/sched/fair.c:844 [inline]
RIP: 0010:rb_add_augmented_cached include/linux/rbtree_augmented.h:83 [inline]
RIP: 0010:__enqueue_entity+0x364/0x5e0 kernel/sched/fair.c:855
Code: c1 e8 03 42 80 3c 28 00 74 08 4c 89 f7 e8 e4 98 89 00 4d 8b 3e 4d 85 ff 74 41 4d 8d 77 20 4c 89 f0 48 c1 e8 03 42 80 3c 28 00 <74> 08 4c 89 f7 e8 c2 98 89 00 4d 8b 36 4c 29 f3 48 85 db 7e 1c 48
RSP: 0018:ffffc90000a08a58 EFLAGS: 00000046
RAX: 1ffff1100673c906 RBX: 00000028829f72b0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880276a80f0
RBP: ffff8880276a80b8 R08: ffff88807de800a7 R09: 0000000000000000
R10: ffff88807de80098 R11: ffffed100fbd0015 R12: ffff8880276a8090
R13: dffffc0000000000 R14: ffff8880339e4830 R15: ffff8880339e4810
FS: 00007fe01545b6c0(0000) GS:ffff8881261f9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe009e07000 CR3: 000000004c812000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
enqueue_entity+0x3fe/0x1120 kernel/sched/fair.c:5362
enqueue_task_fair+0x293/0x14e0 kernel/sched/fair.c:6980
enqueue_task+0x75/0x420 kernel/sched/core.c:2075
activate_task kernel/sched/core.c:2122 [inline]
ttwu_do_activate+0x1ee/0x8b0 kernel/sched/core.c:3732
ttwu_queue kernel/sched/core.c:4000 [inline]
try_to_wake_up+0x745/0x1290 kernel/sched/core.c:4328
hrtimer_wakeup+0x4e/0x60 kernel/time/hrtimer.c:1997
__run_hrtimer kernel/time/hrtimer.c:1761 [inline]
__hrtimer_run_queues+0x529/0xc60 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
__sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1055
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2061 [inline]
RIP: 0010:vprintk_emit+0x58f/0x7a0 kernel/printk/printk.c:2449
Code: 85 32 01 00 00 e8 d1 f2 1e 00 41 89 df 4d 85 f6 48 8b 1c 24 75 07 e8 c0 f2 1e 00 eb 06 e8 b9 f2 1e 00 fb 48 c7 c7 00 1f f3 8d <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 f9 3f
RSP: 0018:ffffc9000b14ed80 EFLAGS: 00000293
RAX: ffffffff81a0fe47 RBX: ffffffff81a0fd04 RCX: ffff88801e7f3c00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8df31f00
RBP: ffffc9000b14ee90 R08: ffffffff8f7dd377 R09: 1ffffffff1efba6e
R10: dffffc0000000000 R11: fffffbfff1efba6f R12: dffffc0000000000
R13: 1ffff92001629db4 R14: 0000000000000200 R15: 000000000000002c
_printk+0xcf/0x120 kernel/printk/printk.c:2475
set_capacity_and_notify+0x208/0x2d0 block/genhd.c:93
loop_set_size+0x44/0xb0 drivers/block/loop.c:210
loop_configure+0xb96/0x1010 drivers/block/loop.c:1067
lo_ioctl+0x79a/0x2410 drivers/block/loop.c:-1
blkdev_ioctl+0x5a5/0x6d0 block/ioctl.c:704
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl+0xf9/0x170 fs/ioctl.c:892
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe01458e56b
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007fe01545adc0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fe01458e56b
RDX: 0000000000000003 RSI: 0000000000004c00 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000021c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007fe01545aef0 R14: 00007fe01545aeb0 R15: 00007fe009e00000