INFO: task kworker/u8:1:13 blocked for more than 122 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:1 state:D stack:0 pid:13 tgid:13 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: context_switch kernel/sched/core.c:6060 [inline] __schedule+0x1496/0x20b0 kernel/sched/core.c:7880 __schedule_loop kernel/sched/core.c:7957 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7972 io_schedule+0x88/0xe0 kernel/sched/core.c:8786 bit_wait_io+0x17/0xd0 kernel/sched/wait_bit.c:209 __wait_on_bit_lock+0x241/0x5e0 kernel/sched/wait_bit.c:90 out_of_line_wait_on_bit_lock+0x139/0x190 kernel/sched/wait_bit.c:117 wait_on_bit_lock_io include/linux/wait_bit.h:208 [inline] __lock_buffer+0x5d/0x70 fs/buffer.c:71 lock_buffer include/linux/buffer_head.h:434 [inline] do_get_write_access+0x196/0xd70 fs/jbd2/transaction.c:972 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+0x1f3/0xee0 fs/ext4/mballoc.c:4094 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+0x3d4/0x7f0 mm/page-writeback.c:2689 __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_background_flush fs/fs-writeback.c:2222 [inline] wb_do_writeback fs/fs-writeback.c:2310 [inline] wb_workfn+0xab0/0xef0 fs/fs-writeback.c:2337 process_one_work kernel/workqueue.c:3273 [inline] process_scheduled_works+0x7f7/0x1060 kernel/workqueue.c:3354 worker_thread+0xc99/0x13f0 kernel/workqueue.c:3435 kthread+0x2c7/0x360 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/sda1-8:73 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:73 tgid:73 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:6060 [inline] __schedule+0x1496/0x20b0 kernel/sched/core.c:7880 __schedule_loop kernel/sched/core.c:7957 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7972 jbd2_journal_wait_updates+0x198/0x280 fs/jbd2/transaction.c:847 jbd2_journal_commit_transaction+0x813/0x5510 fs/jbd2/commit.c:454 kjournald2+0x386/0x6a0 fs/jbd2/journal.c:201 kthread+0x2c7/0x360 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-executor:286 blocked for more than 123 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:0 pid:286 tgid:286 ppid:285 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:6060 [inline] __schedule+0x1496/0x20b0 kernel/sched/core.c:7880 __schedule_loop kernel/sched/core.c:7957 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7972 wait_transaction_locked+0x19e/0x240 fs/jbd2/transaction.c:156 add_transaction_credits fs/jbd2/transaction.c:226 [inline] start_this_handle+0x7de/0x2050 fs/jbd2/transaction.c:407 jbd2__journal_start+0x300/0x860 fs/jbd2/transaction.c:505 __ext4_journal_start_sb+0x111/0x3f0 fs/ext4/ext4_jbd2.c:112 __ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline] ext4_dirty_inode+0x97/0x110 fs/ext4/inode.c:6100 __mark_inode_dirty+0x251/0xc50 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: 0033:0x7f9ba4f6d207 RSP: 002b:00007ffd02549c68 EFLAGS: 00010206 RAX: 00007f9ba2a00000 RBX: 0000555582097a80 RCX: 000000000000055a RDX: 000000000000255a RSI: 00005555821086d0 RDI: 00007f9ba2a02000 RBP: 00007ffd02549c80 R08: 00007f9ba2a00000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055558209b0a0 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000 INFO: task syz.3.19:374 blocked for more than 124 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.19 state:D stack:0 pid:374 tgid:374 ppid:298 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:6060 [inline] __schedule+0x1496/0x20b0 kernel/sched/core.c:7880 __schedule_loop kernel/sched/core.c:7957 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7972 wait_transaction_locked+0x19e/0x240 fs/jbd2/transaction.c:156 add_transaction_credits fs/jbd2/transaction.c:226 [inline] start_this_handle+0x7de/0x2050 fs/jbd2/transaction.c:407 jbd2__journal_start+0x300/0x860 fs/jbd2/transaction.c:505 __ext4_journal_start_sb+0x111/0x3f0 fs/ext4/ext4_jbd2.c:112 __ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline] ext4_dirty_inode+0x97/0x110 fs/ext4/inode.c:6100 __mark_inode_dirty+0x251/0xc50 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: 0033:0x7fe23b672729 RSP: 002b:00007ffdb519ab90 EFLAGS: 00010202 RAX: 0000001b2f422000 RBX: ffffffff827357ff RCX: 0000001b2f421ff8 RDX: 0000001b2f024224 RSI: 0000000000000008 RDI: 00007fe23c555720 RBP: 0000000000000374 R08: 00007fe23ba10000 R09: 00007fe23ba12000 R10: 0000000082735803 R11: 00000000000000ff R12: 00007fe23ba25f40 R13: 0000000000008b98 R14: ffffffff827357ff R15: 00007fe23c555720 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 c4896d72d1fb51cdc6291d08376a37fd8080d7bb Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 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:113 nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline] watchdog+0xe45/0xf90 kernel/hung_task.c:423 kthread+0x2c7/0x360 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 c4896d72d1fb51cdc6291d08376a37fd8080d7bb Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:116 Code: cc cc cc cc cc cc cc b8 68 06 71 8f 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 23 19 43 00 55 48 89 e5 fb f4 <5d> c3 cc cc cc cc cc cc cc cc cc cc cc b8 00 00 00 00 90 90 90 90 RSP: 0018:ffffc900001a7e00 EFLAGS: 000002c2 RAX: ffff8881f6f00000 RBX: ffff88810366a600 RCX: ffffffff85a444fd RDX: 0000000000000001 RSI: 0000000000000004 RDI: 000000000004737c RBP: ffffc900001a7e00 R08: ffff8881f6f395eb R09: 1ffff1103ede72bd R10: dffffc0000000000 R11: ffffed103ede72be R12: 0000000000000000 R13: 1ffff110206cd4c0 R14: dffffc0000000000 R15: ffffffff87ecbfe8 FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f11def99492 CR3: 000000010cb5c000 CR4: 00000000003526b0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:-1 [inline] default_idle+0x17/0x30 arch/x86/kernel/process.c:754 arch_cpu_idle+0xd/0x20 arch/x86/kernel/process.c:791 default_idle_call+0x3e/0x80 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:193 [inline] do_idle+0x2fc/0x570 kernel/sched/idle.c:346 cpu_startup_entry+0x47/0x60 kernel/sched/idle.c:445 start_secondary+0x12e/0x140 arch/x86/kernel/smpboot.c:314 common_startup_64+0x13b/0x157