INFO: task kworker/u8:3:61 blocked for more than 122 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:3 state:D stack:0 pid:61 tgid:61 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: context_switch kernel/sched/core.c:6063 [inline] __schedule+0x1496/0x20b0 kernel/sched/core.c:7883 __schedule_loop kernel/sched/core.c:7960 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7975 io_schedule+0x85/0x150 kernel/sched/core.c:8790 bit_wait_io+0x17/0xd0 kernel/sched/wait_bit.c:209 __wait_on_bit+0xb6/0x2e0 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0x139/0x190 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] do_get_write_access+0x558/0xd70 fs/jbd2/transaction.c:1096 jbd2_journal_get_write_access+0x268/0x3d0 fs/jbd2/transaction.c:1245 __ext4_journal_get_write_access+0x1b6/0x6a0 fs/ext4/ext4_jbd2.c:239 ext4_mb_mark_context+0x393/0xee0 fs/ext4/mballoc.c:4107 ext4_mb_mark_diskspace_used+0x3aa/0x830 fs/ext4/mballoc.c:4223 ext4_mb_new_blocks+0x840/0x36c0 fs/ext4/mballoc.c:6318 ext4_ext_map_blocks+0x14d9/0x6080 fs/ext4/extents.c:4437 ext4_map_create_blocks fs/ext4/inode.c:520 [inline] ext4_map_blocks+0x873/0x17f0 fs/ext4/inode.c:706 mpage_map_one_extent fs/ext4/inode.c:2222 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2275 [inline] ext4_do_writepages+0x1c4a/0x39f0 fs/ext4/inode.c:2738 ext4_writepages+0x28c/0x550 fs/ext4/inode.c:2827 do_writepages+0x3d7/0x7f0 mm/page-writeback.c:2690 __writeback_single_inode+0xc8/0xba0 fs/fs-writeback.c:1674 writeback_sb_inodes+0x6a5/0xfb0 fs/fs-writeback.c:1970 __writeback_inodes_wb+0x129/0x280 fs/fs-writeback.c:2041 wb_writeback+0x3bb/0x850 fs/fs-writeback.c:2152 wb_check_old_data_flush fs/fs-writeback.c:2256 [inline] wb_do_writeback fs/fs-writeback.c:2309 [inline] wb_workfn+0xa03/0xef0 fs/fs-writeback.c:2337 process_one_work kernel/workqueue.c:3273 [inline] process_scheduled_works+0x7f4/0x1060 kernel/workqueue.c:3354 worker_thread+0xc99/0x13f0 kernel/workqueue.c:3435 kthread+0x2c4/0x360 kernel/kthread.c:389 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 INFO: task jbd2/sda1-8:74 blocked for more than 123 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:jbd2/sda1-8 state:D stack:0 pid:74 tgid:74 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:6063 [inline] __schedule+0x1496/0x20b0 kernel/sched/core.c:7883 __schedule_loop kernel/sched/core.c:7960 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7975 io_schedule+0x85/0x150 kernel/sched/core.c:8790 bit_wait_io+0x17/0xd0 kernel/sched/wait_bit.c:209 __wait_on_bit+0xb6/0x2e0 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0x139/0x190 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] __wait_on_buffer+0x5a/0x70 fs/buffer.c:123 wait_on_buffer include/linux/buffer_head.h:422 [inline] jbd2_journal_commit_transaction+0x2dba/0x5510 fs/jbd2/commit.c:814 kjournald2+0x386/0x6a0 fs/jbd2/journal.c:201 kthread+0x2c4/0x360 kernel/kthread.c:389 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 INFO: task syz.3.41:428 blocked for more than 123 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.41 state:D stack:0 pid:428 tgid:428 ppid:397 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:6063 [inline] __schedule+0x1496/0x20b0 kernel/sched/core.c:7883 __schedule_loop kernel/sched/core.c:7960 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7975 io_schedule+0x85/0x150 kernel/sched/core.c:8790 bit_wait_io+0x17/0xd0 kernel/sched/wait_bit.c:209 __wait_on_bit+0xb6/0x2e0 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0x139/0x190 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] do_get_write_access+0x558/0xd70 fs/jbd2/transaction.c:1096 jbd2_journal_get_write_access+0x268/0x3d0 fs/jbd2/transaction.c:1245 __ext4_journal_get_write_access+0x1b6/0x6a0 fs/ext4/ext4_jbd2.c:239 ext4_reserve_inode_write+0x1f6/0x2e0 fs/ext4/inode.c:5892 __ext4_mark_inode_dirty+0xac/0x5e0 fs/ext4/inode.c:6066 ext4_dirty_inode+0xc9/0x110 fs/ext4/inode.c:6103 __mark_inode_dirty+0x24e/0xc50 fs/fs-writeback.c:2515 generic_update_time fs/inode.c:2056 [inline] inode_update_time fs/inode.c:2069 [inline] __file_update_time fs/inode.c:2258 [inline] file_update_time+0x1d3/0x210 fs/inode.c:2288 ext4_page_mkwrite+0x2bf/0x1120 fs/ext4/inode.c:6221 do_page_mkwrite mm/memory.c:3263 [inline] do_shared_fault mm/memory.c:5537 [inline] do_fault mm/memory.c:5599 [inline] do_pte_missing+0x12c4/0x4440 mm/memory.c:4069 handle_pte_fault mm/memory.c:5940 [inline] __handle_mm_fault mm/memory.c:6083 [inline] handle_mm_fault+0x1189/0x1ba0 mm/memory.c:6251 do_user_addr_fault+0x951/0x1230 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1479 [inline] exc_page_fault+0x58/0xc0 arch/x86/mm/fault.c:1534 asm_exc_page_fault+0x2b/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7fa9b586bae3 RSP: 002b:00007ffee7e664f0 EFLAGS: 00010246 RAX: 000000000003fde8 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000001b2d824000 RSI: 0000000000040000 RDI: 00007fa9b5be1708 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffee7e66780 INFO: task syz.0.43:429 blocked for more than 124 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.43 state:D stack:0 pid:429 tgid:429 ppid:385 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:6063 [inline] __schedule+0x1496/0x20b0 kernel/sched/core.c:7883 __schedule_loop kernel/sched/core.c:7960 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7975 io_schedule+0x85/0x150 kernel/sched/core.c:8790 bit_wait_io+0x17/0xd0 kernel/sched/wait_bit.c:209 __wait_on_bit+0xb6/0x2e0 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0x139/0x190 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] do_get_write_access+0x558/0xd70 fs/jbd2/transaction.c:1096 jbd2_journal_get_write_access+0x268/0x3d0 fs/jbd2/transaction.c:1245 __ext4_journal_get_write_access+0x1b6/0x6a0 fs/ext4/ext4_jbd2.c:239 ext4_reserve_inode_write+0x1f6/0x2e0 fs/ext4/inode.c:5892 __ext4_mark_inode_dirty+0xac/0x5e0 fs/ext4/inode.c:6066 ext4_dirty_inode+0xc9/0x110 fs/ext4/inode.c:6103 __mark_inode_dirty+0x24e/0xc50 fs/fs-writeback.c:2515 generic_update_time fs/inode.c:2056 [inline] inode_update_time fs/inode.c:2069 [inline] __file_update_time fs/inode.c:2258 [inline] file_update_time+0x1d3/0x210 fs/inode.c:2288 ext4_page_mkwrite+0x2bf/0x1120 fs/ext4/inode.c:6221 do_page_mkwrite mm/memory.c:3263 [inline] do_shared_fault mm/memory.c:5537 [inline] do_fault mm/memory.c:5599 [inline] do_pte_missing+0x12c4/0x4440 mm/memory.c:4069 handle_pte_fault mm/memory.c:5940 [inline] __handle_mm_fault mm/memory.c:6083 [inline] handle_mm_fault+0x1189/0x1ba0 mm/memory.c:6251 do_user_addr_fault+0x951/0x1230 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1479 [inline] exc_page_fault+0x58/0xc0 arch/x86/mm/fault.c:1534 asm_exc_page_fault+0x2b/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7fdd5c06bae3 RSP: 002b:00007ffd05e3f550 EFLAGS: 00010246 RAX: 000000000003fde8 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000001b2cc24000 RSI: 0000000000040000 RDI: 00007fdd5c3e1708 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffd05e3f7e0 INFO: task syz.1.42:430 blocked for more than 124 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.42 state:D stack:0 pid:430 tgid:430 ppid:390 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:6063 [inline] __schedule+0x1496/0x20b0 kernel/sched/core.c:7883 __schedule_loop kernel/sched/core.c:7960 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7975 io_schedule+0x85/0x150 kernel/sched/core.c:8790 bit_wait_io+0x17/0xd0 kernel/sched/wait_bit.c:209 __wait_on_bit+0xb6/0x2e0 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0x139/0x190 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] do_get_write_access+0x558/0xd70 fs/jbd2/transaction.c:1096 jbd2_journal_get_write_access+0x268/0x3d0 fs/jbd2/transaction.c:1245 __ext4_journal_get_write_access+0x1b6/0x6a0 fs/ext4/ext4_jbd2.c:239 ext4_reserve_inode_write+0x1f6/0x2e0 fs/ext4/inode.c:5892 __ext4_mark_inode_dirty+0xac/0x5e0 fs/ext4/inode.c:6066 ext4_dirty_inode+0xc9/0x110 fs/ext4/inode.c:6103 __mark_inode_dirty+0x24e/0xc50 fs/fs-writeback.c:2515 generic_update_time fs/inode.c:2056 [inline] inode_update_time fs/inode.c:2069 [inline] __file_update_time fs/inode.c:2258 [inline] file_update_time+0x1d3/0x210 fs/inode.c:2288 ext4_page_mkwrite+0x2bf/0x1120 fs/ext4/inode.c:6221 do_page_mkwrite mm/memory.c:3263 [inline] do_shared_fault mm/memory.c:5537 [inline] do_fault mm/memory.c:5599 [inline] do_pte_missing+0x12c4/0x4440 mm/memory.c:4069 handle_pte_fault mm/memory.c:5940 [inline] __handle_mm_fault mm/memory.c:6083 [inline] handle_mm_fault+0x1189/0x1ba0 mm/memory.c:6251 do_user_addr_fault+0x951/0x1230 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1479 [inline] exc_page_fault+0x58/0xc0 arch/x86/mm/fault.c:1534 asm_exc_page_fault+0x2b/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7fe99086bae3 RSP: 002b:00007ffc7a3f1290 EFLAGS: 00010246 RAX: 000000000003fde8 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000001b2ce24000 RSI: 0000000000040000 RDI: 00007fe990be1708 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffc7a3f1520 INFO: task syz.5.44:431 blocked for more than 124 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.44 state:D stack:0 pid:431 tgid:431 ppid:392 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:6063 [inline] __schedule+0x1496/0x20b0 kernel/sched/core.c:7883 __schedule_loop kernel/sched/core.c:7960 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7975 io_schedule+0x85/0x150 kernel/sched/core.c:8790 bit_wait_io+0x17/0xd0 kernel/sched/wait_bit.c:209 __wait_on_bit+0xb6/0x2e0 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0x139/0x190 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] do_get_write_access+0x558/0xd70 fs/jbd2/transaction.c:1096 jbd2_journal_get_write_access+0x268/0x3d0 fs/jbd2/transaction.c:1245 __ext4_journal_get_write_access+0x1b6/0x6a0 fs/ext4/ext4_jbd2.c:239 ext4_reserve_inode_write+0x1f6/0x2e0 fs/ext4/inode.c:5892 __ext4_mark_inode_dirty+0xac/0x5e0 fs/ext4/inode.c:6066 ext4_dirty_inode+0xc9/0x110 fs/ext4/inode.c:6103 __mark_inode_dirty+0x24e/0xc50 fs/fs-writeback.c:2515 generic_update_time fs/inode.c:2056 [inline] inode_update_time fs/inode.c:2069 [inline] __file_update_time fs/inode.c:2258 [inline] file_update_time+0x1d3/0x210 fs/inode.c:2288 ext4_page_mkwrite+0x2bf/0x1120 fs/ext4/inode.c:6221 do_page_mkwrite mm/memory.c:3263 [inline] do_shared_fault mm/memory.c:5537 [inline] do_fault mm/memory.c:5599 [inline] do_pte_missing+0x12c4/0x4440 mm/memory.c:4069 handle_pte_fault mm/memory.c:5940 [inline] __handle_mm_fault mm/memory.c:6083 [inline] handle_mm_fault+0x1189/0x1ba0 mm/memory.c:6251 do_user_addr_fault+0x951/0x1230 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1479 [inline] exc_page_fault+0x58/0xc0 arch/x86/mm/fault.c:1534 asm_exc_page_fault+0x2b/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7fd4ca26bae3 RSP: 002b:00007fffa77ef8a0 EFLAGS: 00010246 RAX: 000000000003fde8 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000001b2d324000 RSI: 0000000000040000 RDI: 00007fd4ca5e1708 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 00007fffa77efb30 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 60889c1c5e6bdc1f3cb1b6a230ba908545dccc71 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:94 dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120 dump_stack+0x19/0x20 lib/dump_stack.c:129 nmi_cpu_backtrace+0x2ba/0x2d0 lib/nmi_backtrace.c:114 nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:63 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41 cpumask_backtrace+0x1f/0x30 lib/nmi_backtrace.c:127 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline] watchdog+0xe45/0xf90 kernel/hung_task.c:423 kthread+0x2c4/0x360 kernel/kthread.c:389 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153 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: 0 Comm: swapper/0 Not tainted syzkaller #0 60889c1c5e6bdc1f3cb1b6a230ba908545dccc71 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 RIP: 0010:_raw_spin_lock_irqsave+0x4d/0x160 kernel/locking/spinlock.c:161 Code: 25 28 00 00 00 48 89 44 24 60 49 bc 00 00 00 00 00 fc ff df 4c 8d 7c 24 20 48 c7 04 24 b3 8a b5 41 48 c7 44 24 08 cc 74 0f 87 <48> c7 44 24 10 e0 8e a7 85 49 89 e5 49 c1 ed 03 48 b8 f1 f1 f1 f1 RSP: 0018:ffffffff87407aa0 EFLAGS: 00000086 RAX: df703474ae917c00 RBX: ffff8881f6e2cec0 RCX: ffffffff874156c0 RDX: 0000000000000000 RSI: fffffffffffffff7 RDI: ffff8881f6e2cec0 RBP: ffffffff87407b60 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffffbfff0e80f58 R12: dffffc0000000000 R13: ffff8881f6e29d40 R14: dffffc0000000000 R15: ffffffff87407ac0 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd1208b2240 CR3: 000000010cb22000 CR4: 00000000003526b0 Call Trace: hrtimer_get_next_event+0x3b/0x810 kernel/time/hrtimer.c:1553 cmp_next_hrtimer_event kernel/time/timer.c:1985 [inline] __get_next_timer_interrupt+0x761/0xa60 kernel/time/timer.c:2327 get_next_timer_interrupt+0x23/0x40 kernel/time/timer.c:2343 tick_nohz_next_event+0x1d9/0x3e0 kernel/time/tick-sched.c:933 tick_nohz_idle_stop_tick+0x114/0x9d0 kernel/time/tick-sched.c:1228 idle_call_stop_or_retain_tick kernel/sched/idle.c:161 [inline] cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1da/0x570 kernel/sched/idle.c:346 cpu_startup_entry+0x47/0x60 kernel/sched/idle.c:445 rest_init+0x10b/0x130 init/main.c:760 start_kernel+0x462/0x4bb init/main.c:1242 x86_64_start_reservations+0x2e/0x30 arch/x86/kernel/head64.c:507 x86_64_start_kernel+0x6a/0x7b arch/x86/kernel/head64.c:488 common_startup_64+0x13b/0x157