INFO: task syz.8.188:7747 blocked for more than 143 seconds.
Not tainted 6.15.0-rc4-syzkaller-00051-g7a13c14ee59d #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.188 state:D stack:24344 pid:7747 tgid:7745 ppid:6714 task_flags:0x400140 flags:0x00004004
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
wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216
sync_inodes_sb+0x1bb/0xa10 fs/fs-writeback.c:2833
iterate_supers+0xb5/0x180 fs/super.c:934
ksys_sync+0x94/0x150 fs/sync.c:102
__ia32_sys_sync+0xe/0x20 fs/sync.c:113
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: 0033:0x7fbbe458e969
RSP: 002b:00007fbbe23f6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fbbe47b5fa0 RCX: 00007fbbe458e969
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fbbe47b5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fbbe47b5fa0 R15: 00007ffc763185a8
Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
1 lock held by khungtaskd/31:
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764
2 locks held by kworker/u8:10/3503:
#0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc9000c8b7c60 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000c8b7c60 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
3 locks held by kworker/u8:11/3525:
#0: ffff88801fe93948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801fe93948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc9000c607c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000c607c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
#2: ffff8880299780e0 (&type->s_umount_key#75){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562
2 locks held by getty/5575:
#0: ffff88814d2350a0 (&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
2 locks held by syz.3.37/6114:
#0: ffff88801ffbbb38 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1213
#1: ffff888029978420 (sb_writers#19){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline]
#1: ffff888029978420 (sb_writers#19){.+.+}-{0:0}, at: vfs_write+0x211/0xa90 fs/read_write.c:680
2 locks held by syz.8.188/7747:
#0: ffff8880299780e0 (&type->s_umount_key#75){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff8880299780e0 (&type->s_umount_key#75){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
#1: ffff88802997a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
#1: ffff88802997a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831
2 locks held by syz.2.469/10084:
#0: ffff8880299780e0 (&type->s_umount_key#75){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff8880299780e0 (&type->s_umount_key#75){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
#1: ffff88802997a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
#1: ffff88802997a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831
2 locks held by syz.0.518/10484:
#0: ffff8880299780e0 (&type->s_umount_key#75){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff8880299780e0 (&type->s_umount_key#75){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
#1: ffff88802997a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
#1: ffff88802997a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831
2 locks held by syz.8.530/10572:
2 locks held by dhcpcd-run-hook/10598:
#0: ffff8880b89399d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605
#1: ffff88805c8294b8 (&sb->s_type->i_lock_key#15){+.+.}-{3:3}, at: read_seqbegin include/linux/seqlock.h:836 [inline]
#1: ffff88805c8294b8 (&sb->s_type->i_lock_key#15){+.+.}-{3:3}, at: read_seqbegin_or_lock_irqsave include/linux/seqlock.h:1187 [inline]
#1: ffff88805c8294b8 (&sb->s_type->i_lock_key#15){+.+.}-{3:3}, at: thread_group_cputime+0x110/0x7d0 kernel/sched/cputime.c:334
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc4-syzkaller-00051-g7a13c14ee59d #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
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: 974 Comm: kworker/u8:5 Not tainted 6.15.0-rc4-syzkaller-00051-g7a13c14ee59d #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:do_sync_core+0x39/0x60 arch/x86/kernel/alternative.c:2451
Code: 6d 4b 59 00 0f 01 e8 c3 cc cc cc cc cc f3 0f 1e fa e8 5b 4b 59 00 8c d0 50 54 48 83 04 24 08 9c 8c c8 50 68 19 74 66 81 48 cf cc cc cc cc cc f3 0f 1e fa e8 38 4b 59 00 0f 01 e8 c3 cc cc cc
RSP: 0018:ffffc900038ef6f8 EFLAGS: 00000082
RAX: 0000000000000010 RBX: 0000000000000200 RCX: ffff888024ed5a00
RDX: 0000000000000000 RSI: ffffffff8bc0fa40 RDI: 0000000000000000
RBP: ffffc900038ef860 R08: ffffffff8f7daa77 R09: 1ffffffff1efb54e
R10: dffffc0000000000 R11: ffffffff816673e0 R12: ffff8880b893abc0
R13: dffffc0000000000 R14: ffffffff816673e0 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888126200000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a8fe7c5950 CR3: 000000000dd36000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
csd_do_func kernel/smp.c:134 [inline]
smp_call_function_many_cond+0xaaf/0x11c0 kernel/smp.c:876
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052
on_each_cpu include/linux/smp.h:71 [inline]
text_poke_sync arch/x86/kernel/alternative.c:2455 [inline]
text_poke_bp_batch+0x61a/0x940 arch/x86/kernel/alternative.c:2727
text_poke_flush arch/x86/kernel/alternative.c:2856 [inline]
text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2863
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_disable_cpuslocked+0xc5/0x1b0 kernel/jump_label.c:240
static_key_disable+0x1a/0x20 kernel/jump_label.c:248
toggle_allocation_gate+0x1a1/0x240 mm/kfence/core.c:855
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