INFO: task kworker/u8:1:13 blocked for more than 143 seconds. Not tainted 6.15.0-rc4-syzkaller-00042-gb6ea1680d0ac #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:1 state:D stack:23576 pid:13 tgid:13 ppid:2 task_flags:0x4248060 flags:0x00004000 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 io_schedule+0xbf/0x130 kernel/sched/core.c:7742 bit_wait_io+0x15/0xe0 kernel/sched/wait_bit.c:247 __wait_on_bit+0x62/0x180 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0xd9/0x110 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:105 [inline] do_get_write_access+0x93d/0x12a0 fs/jbd2/transaction.c:1092 jbd2_journal_get_write_access+0x1d6/0x280 fs/jbd2/transaction.c:1241 __ext4_journal_get_write_access+0x6a/0x340 fs/ext4/ext4_jbd2.c:241 ext4_reserve_inode_write+0x1be/0x320 fs/ext4/inode.c:5892 __ext4_mark_inode_dirty+0x197/0x870 fs/ext4/inode.c:6066 __ext4_ext_dirty+0x1ae/0x230 fs/ext4/extents.c:207 ext4_ext_insert_extent+0x19bb/0x4610 fs/ext4/extents.c:2190 ext4_ext_map_blocks+0x205b/0x5d60 fs/ext4/extents.c:4400 ext4_map_create_blocks fs/ext4/inode.c:520 [inline] ext4_map_blocks+0x45b/0x1390 fs/ext4/inode.c:706 mpage_map_one_extent fs/ext4/inode.c:2224 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2277 [inline] ext4_do_writepages+0x1a2c/0x3490 fs/ext4/inode.c:2739 ext4_writepages+0x37a/0x7d0 fs/ext4/inode.c:2829 do_writepages+0x1b2/0x820 mm/page-writeback.c:2656 __writeback_single_inode+0x160/0xfb0 fs/fs-writeback.c:1680 writeback_sb_inodes+0x601/0xf90 fs/fs-writeback.c:1976 __writeback_inodes_wb+0xf8/0x2d0 fs/fs-writeback.c:2047 wb_writeback+0x7f3/0xb70 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+0x8ca/0xbe0 fs/fs-writeback.c:2343 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task jbd2/sda1-8:5161 blocked for more than 144 seconds. Not tainted 6.15.0-rc4-syzkaller-00042-gb6ea1680d0ac #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:jbd2/sda1-8 state:D stack:26008 pid:5161 tgid:5161 ppid:2 task_flags:0x240040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 io_schedule+0xbf/0x130 kernel/sched/core.c:7742 bit_wait_io+0x15/0xe0 kernel/sched/wait_bit.c:247 __wait_on_bit+0x62/0x180 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0xd9/0x110 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:105 [inline] __wait_on_buffer+0x64/0x70 fs/buffer.c:123 wait_on_buffer include/linux/buffer_head.h:422 [inline] jbd2_journal_commit_transaction+0x382e/0x6830 fs/jbd2/commit.c:808 kjournald2+0x1f4/0x760 fs/jbd2/journal.c:201 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 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: 6 locks held by kworker/u8:1/13: #0: ffff888021ebd148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90000127d18 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88814dd1c0e0 (&type->s_umount_key#32){++++}-{4:4}, at: super_trylock_shared+0x1e/0xf0 fs/super.c:562 #3: ffff88814dd1eb98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x1b2/0x820 mm/page-writeback.c:2656 #4: ffff888034448950 (jbd2_handle){.+.+}-{0:0}, at: start_this_handle+0x5e4/0x1410 fs/jbd2/transaction.c:444 #5: ffff888078ca82c8 (&ei->i_data_sem){++++}-{4:4}, at: ext4_map_blocks+0x355/0x1390 fs/ext4/inode.c:705 1 lock held by khungtaskd/31: #0: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6764 5 locks held by kworker/u8:7/2902: #0: ffff8880b8439f18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:605 #1: ffff8880b8423c48 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x2c1/0x8e0 kernel/sched/psi.c:987 #2: ffff8880b84256d8 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x127/0x1d0 kernel/time/timer.c:1046 #3: ffffffff9ad8fb58 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x14c/0x4c0 lib/debugobjects.c:818 #4: ffffffff8e27e6c8 (text_mutex){+.+.}-{4:4}, at: arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:145 2 locks held by getty/5582: #0: ffff88814dc780a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002ffe2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc4-syzkaller-00042-gb6ea1680d0ac #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/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+0xf70/0x12c0 kernel/hung_task.c:437 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 18223 Comm: syz-executor367 Not tainted 6.15.0-rc4-syzkaller-00042-gb6ea1680d0ac #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3799 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3822 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3877 [inline] RIP: 0010:__lock_acquire+0xace/0x1ba0 kernel/locking/lockdep.c:5235 Code: 4c 8b 04 24 48 b8 eb 83 b5 80 46 86 c8 61 49 0f af c0 48 c1 e8 2d 48 8d 0c c5 00 70 e7 96 48 89 04 24 48 8b 04 c5 00 70 e7 96 <48> 89 4c 24 08 48 85 c0 48 8d 48 f8 48 0f 45 c1 eb 04 48 83 e8 08 RSP: 0018:ffffc90000007bf8 EFLAGS: 00000003 RAX: ffffffff93a9fc28 RBX: ffff8880293a6518 RCX: ffffffff97030cd8 RDX: afe4153863a2af51 RSI: 0000000027794cc0 RDI: ffff8880293a6518 RBP: ffff8880293a64f0 R08: afe4153863a2af51 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000055 R13: 0000000000000001 R14: ffff8880293a5a00 R15: 0000000000000000 FS: 000055555d116380(0000) GS:ffff8881249ed000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000001 CR3: 000000007f05e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire kernel/locking/lockdep.c:5866 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5823 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 expire_timers kernel/time/timer.c:1836 [inline] __run_timers+0x571/0x960 kernel/time/timer.c:2414 __run_timer_base kernel/time/timer.c:2426 [inline] __run_timer_base kernel/time/timer.c:2418 [inline] run_timer_base+0x114/0x190 kernel/time/timer.c:2435 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2445 handle_softirqs+0x216/0x8e0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 Code: 90 f3 0f 1e fa 53 48 8b 74 24 08 48 89 fb 48 83 c7 18 e8 ba 06 2c f6 48 89 df e8 62 5a 2c f6 e8 9d d2 56 f6 fb bf 01 00 00 00 c2 c6 1c f6 65 8b 05 ab 94 37 08 85 c0 74 06 5b c3 cc cc cc cc RSP: 0018:ffffc90003007b90 EFLAGS: 00000206 RAX: 0000000000000127 RBX: ffffffff8efba3a0 RCX: 0000000000000007 RDX: 0000000000000000 RSI: ffffffff8dbdad3b RDI: 0000000000000001 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90851a17 R11: 0000000000000000 R12: ffff8881442ff000 R13: 0000000000000004 R14: ffffffff8b5cce70 R15: ffff888078e25038 pci_user_write_config_byte+0x137/0x210 drivers/pci/access.c:276 proc_bus_pci_write+0x451/0x4c0 drivers/pci/proc.c:176 pde_write fs/proc/inode.c:330 [inline] proc_reg_write+0x23d/0x330 fs/proc/inode.c:342 do_loop_readv_writev fs/read_write.c:848 [inline] do_loop_readv_writev fs/read_write.c:833 [inline] vfs_writev+0x6c4/0xdc0 fs/read_write.c:1057 do_writev+0x132/0x330 fs/read_write.c:1101 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0cec948a79 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe4f6702d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0cec948a79 RDX: 0000000000000006 RSI: 0000200000001d40 RDI: 0000000000000003 RBP: 00000000000695f2 R08: 0000000000000006 R09: 0000000000000006 R10: 0000000000000006 R11: 0000000000000246 R12: 00007ffe4f6702ec R13: 431bde82d7b634db R14: 0000000000000001 R15: 0000000000000001 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.489 msecs