INFO: task kworker/u8:5:91 blocked in I/O wait for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:5 state:D stack:22568 pid:91 tgid:91 ppid:2 task_flags:0x4248060 flags:0x00080000 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: context_switch kernel/sched/core.c:5583 [inline] __schedule+0x17dd/0x5830 kernel/sched/core.c:7382 __schedule_loop kernel/sched/core.c:7459 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7474 io_schedule+0x7f/0xd0 kernel/sched/core.c:8146 rq_qos_wait+0x266/0x360 block/blk-rq-qos.c:307 __wbt_wait block/blk-wbt.c:598 [inline] wbt_wait+0x326/0x550 block/blk-wbt.c:658 __rq_qos_throttle+0x6b/0xb0 block/blk-rq-qos.c:66 rq_qos_throttle block/blk-rq-qos.h:164 [inline] blk_mq_get_new_requests block/blk-mq.c:3056 [inline] blk_mq_submit_bio+0x1697/0x2c40 block/blk-mq.c:3198 __submit_bio_noacct_mq block/blk-core.c:757 [inline] submit_bio_noacct_nocheck+0x2fe/0xb10 block/blk-core.c:791 blk_crypto_submit_bio include/linux/blk-crypto.h:212 [inline] ext4_io_submit fs/ext4/page-io.c:399 [inline] io_submit_add_bh fs/ext4/page-io.c:455 [inline] ext4_bio_write_folio+0x101a/0x18c0 fs/ext4/page-io.c:550 mpage_process_page_bufs+0x6bd/0x8a0 fs/ext4/inode.c:2327 mpage_prepare_extent_to_map+0xf8d/0x1880 fs/ext4/inode.c:2875 ext4_do_writepages+0xc08/0x44a0 fs/ext4/inode.c:3023 ext4_writepages+0x1fe/0x4e0 fs/ext4/inode.c:3171 do_writepages+0x338/0x560 mm/page-writeback.c:2562 __writeback_single_inode+0x136/0x1220 fs/fs-writeback.c:1809 writeback_sb_inodes+0x9de/0x1af0 fs/fs-writeback.c:2120 __writeback_inodes_wb+0x114/0x250 fs/fs-writeback.c:2196 wb_writeback+0x42f/0xad0 fs/fs-writeback.c:2307 wb_check_old_data_flush fs/fs-writeback.c:2411 [inline] wb_do_writeback fs/fs-writeback.c:2490 [inline] wb_workfn+0xc92/0x10f0 fs/fs-writeback.c:2518 process_one_work kernel/workqueue.c:3495 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task jbd2/sda1-8:4967 blocked in I/O wait for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:jbd2/sda1-8 state:D stack:26280 pid:4967 tgid:4967 ppid:2 task_flags:0x240040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5583 [inline] __schedule+0x17dd/0x5830 kernel/sched/core.c:7382 __schedule_loop kernel/sched/core.c:7459 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7474 io_schedule+0x7f/0xd0 kernel/sched/core.c:8146 bit_wait_io+0x13/0x110 kernel/sched/wait_bit.c:258 __wait_on_bit+0xac/0x300 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67 wait_on_buffer include/linux/buffer_head.h:476 [inline] jbd2_journal_commit_transaction+0x2f6e/0x5c80 fs/jbd2/commit.c:834 kjournald2+0x3bc/0x740 fs/jbd2/journal.c:200 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz-executor:5622 blocked in I/O wait for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21736 pid:5622 tgid:5622 ppid:5621 task_flags:0x440100 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5583 [inline] __schedule+0x17dd/0x5830 kernel/sched/core.c:7382 __schedule_loop kernel/sched/core.c:7459 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7474 io_schedule+0x7f/0xd0 kernel/sched/core.c:8146 bit_wait_io+0x13/0x110 kernel/sched/wait_bit.c:258 __wait_on_bit+0xac/0x300 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67 wait_on_bit_io include/linux/wait_bit.h:106 [inline] do_get_write_access+0x658/0x10c0 fs/jbd2/transaction.c:1113 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263 __ext4_journal_get_write_access+0xec/0x620 fs/ext4/ext4_jbd2.c:253 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:7451 __ext4_mark_inode_dirty+0x141/0x7e0 fs/ext4/inode.c:7642 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:7679 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2751 generic_update_time fs/inode.c:2264 [inline] file_update_time_flags+0x399/0x440 fs/inode.c:2494 ext4_page_mkwrite+0x21f/0x1470 fs/ext4/inode.c:7864 do_page_mkwrite+0x147/0x310 mm/memory.c:3889 wp_page_shared mm/memory.c:4295 [inline] do_wp_page+0x1a77/0x4c30 mm/memory.c:4518 handle_pte_fault mm/memory.c:6692 [inline] __handle_mm_fault mm/memory.c:6817 [inline] handle_mm_fault+0x19c9/0x2f80 mm/memory.c:6984 do_user_addr_fault+0xb35/0x1480 arch/x86/mm/fault.c:1343 handle_page_fault arch/x86/mm/fault.c:1483 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0033:0x7efe42c7df91 RSP: 002b:00007ffe405b5150 EFLAGS: 00010202 RAX: 0000000000000040 RBX: 0000000000000001 RCX: 0000000000000006 RDX: 00007efe40d40000 RSI: 00000000000037be RDI: ffffffff813fffff RBP: 00007ffe405b5650 R08: 0000000000001000 R09: 0000555555cb6480 R10: 00000000000000a3 R11: 0000555555cb6498 R12: 00007ffe405b5490 R13: 00007ffe405b5280 R14: 585858582e7a7973 R15: 00007ffe405b51d0 INFO: task syz.1.1480:9777 blocked in I/O wait for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.1480 state:D stack:24616 pid:9777 tgid:9777 ppid:5637 task_flags:0x440040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5583 [inline] __schedule+0x17dd/0x5830 kernel/sched/core.c:7382 __schedule_loop kernel/sched/core.c:7459 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7474 io_schedule+0x7f/0xd0 kernel/sched/core.c:8146 bit_wait_io+0x13/0x110 kernel/sched/wait_bit.c:258 __wait_on_bit+0xac/0x300 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67 wait_on_bit_io include/linux/wait_bit.h:106 [inline] do_get_write_access+0x658/0x10c0 fs/jbd2/transaction.c:1113 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263 __ext4_journal_get_write_access+0xec/0x620 fs/ext4/ext4_jbd2.c:253 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:7451 __ext4_mark_inode_dirty+0x141/0x7e0 fs/ext4/inode.c:7642 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:7679 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2751 generic_update_time fs/inode.c:2264 [inline] file_update_time_flags+0x399/0x440 fs/inode.c:2494 ext4_page_mkwrite+0x21f/0x1470 fs/ext4/inode.c:7864 do_page_mkwrite+0x147/0x310 mm/memory.c:3889 do_shared_fault mm/memory.c:6188 [inline] do_fault mm/memory.c:6250 [inline] do_pte_missing+0x70f/0x3570 mm/memory.c:4778 handle_pte_fault mm/memory.c:6665 [inline] __handle_mm_fault mm/memory.c:6817 [inline] handle_mm_fault+0x1807/0x2f80 mm/memory.c:6984 do_user_addr_fault+0xb35/0x1480 arch/x86/mm/fault.c:1343 handle_page_fault arch/x86/mm/fault.c:1483 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0033:0x7fbf13c740b1 RSP: 002b:00007ffdf9fce2e0 EFLAGS: 00010202 RAX: 0000001b34f1d000 RBX: ffffffff8a3c7132 RCX: 0000001b34f1cff8 RDX: 0000001b34924220 RSI: 0000000000000008 RDI: 00007fbf14b55720 RBP: 00000000000000f2 R08: 00007fbf14010000 R09: 00007fbf14012000 R10: 000000008a3c7136 R11: 0000000000000001 R12: 00007fbf14026038 R13: 00000000000002a9 R14: ffffffff8a3c7a75 R15: 00007fbf14b55720 INFO: task syz.4.1481:9782 blocked in I/O wait for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.1481 state:D stack:26696 pid:9782 tgid:9782 ppid:5645 task_flags:0x440040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5583 [inline] __schedule+0x17dd/0x5830 kernel/sched/core.c:7382 __schedule_loop kernel/sched/core.c:7459 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7474 io_schedule+0x7f/0xd0 kernel/sched/core.c:8146 bit_wait_io+0x13/0x110 kernel/sched/wait_bit.c:258 __wait_on_bit+0xac/0x300 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67 wait_on_bit_io include/linux/wait_bit.h:106 [inline] do_get_write_access+0x658/0x10c0 fs/jbd2/transaction.c:1113 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263 __ext4_journal_get_write_access+0xec/0x620 fs/ext4/ext4_jbd2.c:253 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:7451 __ext4_mark_inode_dirty+0x141/0x7e0 fs/ext4/inode.c:7642 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:7679 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2751 generic_update_time fs/inode.c:2264 [inline] touch_atime+0x568/0x670 fs/inode.c:2339 file_accessed include/linux/fs.h:2283 [inline] ext4_file_mmap_prepare+0x277/0x450 fs/ext4/file.c:919 vfs_mmap_prepare include/linux/fs.h:2075 [inline] call_mmap_prepare mm/vma.c:2976 [inline] __mmap_region mm/vma.c:3093 [inline] mmap_region+0x1191/0x2820 mm/vma.c:3191 do_mmap+0xe0a/0x1300 mm/mmap.c:573 vm_mmap_pgoff+0x27a/0x520 mm/util.c:581 ksys_mmap_pgoff+0x4dc/0x760 mm/mmap.c:619 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1a1f59f882 RSP: 002b:00007ffd08f04b58 EFLAGS: 00000206 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 0000001b2cc64000 RCX: 00007f1a1f59f882 RDX: 0000000000000003 RSI: 00000000005c0000 RDI: 0000001b2cc64000 RBP: 0000000000100001 R08: 0000000000000004 R09: 0000000000040000 R10: 0000000000100001 R11: 0000000000000206 R12: 000000000000012a R13: 00000000000927c0 R14: 0000000000036e21 R15: 00007ffd08f04e30 Showing all locks held in the system: locks held by khungtaskd/35: 1, last CPU#0: #0: ffffffff9015a560 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff9015a560 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff9015a560 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871 locks held by kworker/u8:5/91: 4, on CPU#0: #0: ffff888021e95148 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff888021e95148 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff888021e95148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #0: ffff888021e95148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 #1: ffffc9000207fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc9000207fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc9000207fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #1: ffffc9000207fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 #2: ffff88803502e100 (&type->s_umount_key#35){++++}-{4:4}, at: super_trylock_shared+0x23/0xf0 fs/super.c:642 #3: ffff88803791ccd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1f1/0x4e0 fs/ext4/inode.c:3170 locks held by getty/5390: 2, on CPU#1: #0: ffff8880357090a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322e2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211 locks held by syz-executor/5622: 3, on CPU#0: #0: ffff88807b50b808 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:339 #1: ffff88803502e570 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline] #1: ffff88803502e570 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1fe/0x1470 fs/ext4/inode.c:7863 #2: ffff88803502c950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fb0/0x21f0 fs/jbd2/transaction.c:444 locks held by syz.1.1480/9777: 3, on CPU#0: #0: ffff88802d7b4e48 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:339 #1: ffff88803502e570 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline] #1: ffff88803502e570 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1fe/0x1470 fs/ext4/inode.c:7863 #2: ffff88803502c950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fb0/0x21f0 fs/jbd2/transaction.c:444 locks held by syz.4.1481/9782: 3, on CPU#0: #0: ffff88807cb13440 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:566 [inline] #0: ffff88807cb13440 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1ed/0x520 mm/util.c:579 #1: ffff88803502e478 (sb_writers#4){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2283 [inline] #1: ffff88803502e478 (sb_writers#4){.+.+}-{0:0}, at: ext4_file_mmap_prepare+0x277/0x450 fs/ext4/file.c:919 #2: ffff88803502c950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fb0/0x21f0 fs/jbd2/transaction.c:444 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 35 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:377 [inline] watchdog+0x1073/0x10f0 kernel/hung_task.c:598 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245