syzbot


INFO: task kworker/u8:NUM:NUM blocked in I/O wait for more than NUM seconds. (2)

Status: upstream: reported on 2026/05/25 18:08
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+ce3f1479b6afc3f5d0cc@syzkaller.appspotmail.com
First crash: 16d, last: 1d17h
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
e4ea10af-84c6-4cb6-8f34-03b9f65a72f4 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ✅ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ INFO: task kworker/u8:NUM:NUM blocked in I/O wait for more than NUM seconds. (2) 2026/05/23 08:51 2026/05/23 08:51 2026/05/23 10:05 c69befb30ac10e158cc9d1557b508ee3f0eca1de
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[syzbot] INFO: task kworker/u8:NUM:NUM blocked in I/O wait for more than NUM seconds. (2) 0 (1) 2026/05/25 18:08
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task kworker/u8:NUM:NUM blocked in I/O wait for more than NUM seconds. -1 1 33d 33d 0/29 closed as invalid on 2026/04/25 02:11

Sample crash report:
INFO: task kworker/u8:6:1008 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/u8:6    state:D stack:20696 pid:1008  tgid:1008  ppid:2      task_flags:0x4248060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1295/0x67a0 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7283
 io_schedule+0x8a/0xf0 kernel/sched/core.c:8110
 bit_wait_io+0xd/0xe0 kernel/sched/wait_bit.c:250
 __wait_on_bit+0x65/0x180 kernel/sched/wait_bit.c:52
 out_of_line_wait_on_bit+0xdc/0x110 kernel/sched/wait_bit.c:67
 wait_on_bit_io include/linux/wait_bit.h:105 [inline]
 do_get_write_access+0x84f/0x1220 fs/jbd2/transaction.c:1113
 jbd2_journal_get_write_access+0x1d6/0x280 fs/jbd2/transaction.c:1263
 __ext4_journal_get_write_access+0x6a/0x340 fs/ext4/ext4_jbd2.c:241
 ext4_reserve_inode_write+0x1b7/0x330 fs/ext4/inode.c:6375
 __ext4_mark_inode_dirty+0x18f/0x890 fs/ext4/inode.c:6550
 __ext4_ext_dirty+0x1b2/0x230 fs/ext4/extents.c:207
 ext4_ext_insert_extent+0x11ff/0x4540 fs/ext4/extents.c:2210
 ext4_ext_map_blocks+0x21c8/0x5930 fs/ext4/extents.c:4482
 ext4_map_create_blocks+0xec/0x5e0 fs/ext4/inode.c:631
 ext4_map_blocks+0x46b/0xd30 fs/ext4/inode.c:824
 mpage_map_one_extent fs/ext4/inode.c:2396 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2490 [inline]
 ext4_do_writepages+0x2313/0x3f20 fs/ext4/inode.c:2948
 ext4_writepages+0x347/0x790 fs/ext4/inode.c:3042
 do_writepages+0x278/0x600 mm/page-writeback.c:2571
 __writeback_single_inode+0x164/0x1350 fs/fs-writeback.c:1764
 writeback_sb_inodes+0x766/0x1c60 fs/fs-writeback.c:2056
 __writeback_inodes_wb+0xf8/0x2d0 fs/fs-writeback.c:2132
 wb_writeback+0x720/0xb90 fs/fs-writeback.c:2243
 wb_check_old_data_flush fs/fs-writeback.c:2347 [inline]
 wb_do_writeback fs/fs-writeback.c:2400 [inline]
 wb_workfn+0x8dd/0xc00 fs/fs-writeback.c:2428
 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314
 process_scheduled_works kernel/workqueue.c:3397 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
INFO: task jbd2/sda1-8:4956 blocked in I/O wait for more than 144 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:27000 pid:4956  tgid:4956  ppid:2      task_flags:0x240040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1295/0x67a0 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7283
 io_schedule+0x8a/0xf0 kernel/sched/core.c:8110
 bit_wait_io+0xd/0xe0 kernel/sched/wait_bit.c:250
 __wait_on_bit+0x65/0x180 kernel/sched/wait_bit.c:52
 out_of_line_wait_on_bit+0xdc/0x110 kernel/sched/wait_bit.c:67
 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:420 [inline]
 jbd2_journal_commit_transaction+0x388a/0x6870 fs/jbd2/commit.c:837
 kjournald2+0x200/0x760 fs/jbd2/journal.c:201
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
INFO: task syz-executor:5615 blocked in I/O wait for more than 144 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:22480 pid:5615  tgid:5615  ppid:5614   task_flags:0x440100 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1295/0x67a0 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7283
 io_schedule+0x8a/0xf0 kernel/sched/core.c:8110
 bit_wait_io+0xd/0xe0 kernel/sched/wait_bit.c:250
 __wait_on_bit+0x65/0x180 kernel/sched/wait_bit.c:52
 out_of_line_wait_on_bit+0xdc/0x110 kernel/sched/wait_bit.c:67
 wait_on_bit_io include/linux/wait_bit.h:105 [inline]
 do_get_write_access+0x84f/0x1220 fs/jbd2/transaction.c:1113
 jbd2_journal_get_write_access+0x1d6/0x280 fs/jbd2/transaction.c:1263
 __ext4_journal_get_write_access+0x6a/0x340 fs/ext4/ext4_jbd2.c:241
 ext4_reserve_inode_write+0x1b7/0x330 fs/ext4/inode.c:6375
 __ext4_mark_inode_dirty+0x18f/0x890 fs/ext4/inode.c:6550
 ext4_dirty_inode+0xd9/0x130 fs/ext4/inode.c:6587
 __mark_inode_dirty+0x1f3/0x1720 fs/fs-writeback.c:2623
 generic_update_time fs/inode.c:2198 [inline]
 file_update_time_flags+0x46b/0x500 fs/inode.c:2428
 ext4_page_mkwrite+0x324/0x1890 fs/ext4/inode.c:6753
 do_page_mkwrite+0x17a/0x440 mm/memory.c:3684
 do_shared_fault mm/memory.c:5985 [inline]
 do_fault+0x3b5/0x1750 mm/memory.c:6047
 do_pte_missing mm/memory.c:4566 [inline]
 handle_pte_fault mm/memory.c:6427 [inline]
 __handle_mm_fault+0x187d/0x2a00 mm/memory.c:6565
 handle_mm_fault+0x36d/0xa20 mm/memory.c:6734
 do_user_addr_fault+0x5a3/0x12f0 arch/x86/mm/fault.c:1334
 handle_page_fault arch/x86/mm/fault.c:1474 [inline]
 exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1527
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f7c33c7b467
RSP: 002b:00007ffd3e90b380 EFLAGS: 00010202
RAX: 00007f7c31f0c000 RBX: 00005555940107b0 RCX: 0000000000000006
RDX: 0000000000000ed3 RSI: 000055559400d0d8 RDI: 0000000000000040
RBP: 00007ffd3e90b880 R08: 00000000000000c4 R09: 000055559400d0d8
R10: 00007f7c33c00000 R11: 0000000000000202 R12: 00007ffd3e90b6c0
R13: 00007ffd3e90b4b0 R14: 585858582e7a7973 R15: 00007ffd3e90b400
 </TASK>
INFO: task syz.3.261:7085 blocked in I/O wait for more than 144 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.261       state:D stack:27128 pid:7085  tgid:7085  ppid:5630   task_flags:0x440040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1295/0x67a0 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7283
 io_schedule+0x8a/0xf0 kernel/sched/core.c:8110
 bit_wait_io+0xd/0xe0 kernel/sched/wait_bit.c:250
 __wait_on_bit+0x65/0x180 kernel/sched/wait_bit.c:52
 out_of_line_wait_on_bit+0xdc/0x110 kernel/sched/wait_bit.c:67
 wait_on_bit_io include/linux/wait_bit.h:105 [inline]
 do_get_write_access+0x84f/0x1220 fs/jbd2/transaction.c:1113
 jbd2_journal_get_write_access+0x1d6/0x280 fs/jbd2/transaction.c:1263
 __ext4_journal_get_write_access+0x6a/0x340 fs/ext4/ext4_jbd2.c:241
 ext4_reserve_inode_write+0x1b7/0x330 fs/ext4/inode.c:6375
 __ext4_mark_inode_dirty+0x18f/0x890 fs/ext4/inode.c:6550
 ext4_dirty_inode+0xd9/0x130 fs/ext4/inode.c:6587
 __mark_inode_dirty+0x1f3/0x1720 fs/fs-writeback.c:2623
 generic_update_time fs/inode.c:2198 [inline]
 file_update_time_flags+0x46b/0x500 fs/inode.c:2428
 ext4_page_mkwrite+0x324/0x1890 fs/ext4/inode.c:6753
 do_page_mkwrite+0x17a/0x440 mm/memory.c:3684
 do_shared_fault mm/memory.c:5985 [inline]
 do_fault+0x3b5/0x1750 mm/memory.c:6047
 do_pte_missing mm/memory.c:4566 [inline]
 handle_pte_fault mm/memory.c:6427 [inline]
 __handle_mm_fault+0x187d/0x2a00 mm/memory.c:6565
 handle_mm_fault+0x36d/0xa20 mm/memory.c:6734
 do_user_addr_fault+0x5a3/0x12f0 arch/x86/mm/fault.c:1334
 handle_page_fault arch/x86/mm/fault.c:1474 [inline]
 exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1527
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f5e25071580
RSP: 002b:00007ffdb95adcf0 EFLAGS: 00010202
RAX: 0000001b34904000 RBX: ffffffff89ed2dd7 RCX: 0000001b34903ff8
RDX: 0000001b34524220 RSI: 0000000000000008 RDI: 00007f5e25f45720
RBP: 0000000000000078 R08: 00007f5e25400000 R09: 00007f5e25402000
R10: 0000000089ed2ddb R11: 0000000000000017 R12: 00007f5e25416128
R13: 0000000000000077 R14: ffffffff89ed2dd7 R15: 00007f5e25f45720
 </TASK>
INFO: task syz.2.260:7087 blocked in I/O wait for more than 145 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.260       state:D stack:27128 pid:7087  tgid:7087  ppid:5637   task_flags:0x440040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1295/0x67a0 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7283
 io_schedule+0x8a/0xf0 kernel/sched/core.c:8110
 bit_wait_io+0xd/0xe0 kernel/sched/wait_bit.c:250
 __wait_on_bit+0x65/0x180 kernel/sched/wait_bit.c:52
 out_of_line_wait_on_bit+0xdc/0x110 kernel/sched/wait_bit.c:67
 wait_on_bit_io include/linux/wait_bit.h:105 [inline]
 do_get_write_access+0x84f/0x1220 fs/jbd2/transaction.c:1113
 jbd2_journal_get_write_access+0x1d6/0x280 fs/jbd2/transaction.c:1263
 __ext4_journal_get_write_access+0x6a/0x340 fs/ext4/ext4_jbd2.c:241
 ext4_reserve_inode_write+0x1b7/0x330 fs/ext4/inode.c:6375
 __ext4_mark_inode_dirty+0x18f/0x890 fs/ext4/inode.c:6550
 ext4_dirty_inode+0xd9/0x130 fs/ext4/inode.c:6587
 __mark_inode_dirty+0x1f3/0x1720 fs/fs-writeback.c:2623
 generic_update_time fs/inode.c:2198 [inline]
 file_update_time_flags+0x46b/0x500 fs/inode.c:2428
 ext4_page_mkwrite+0x324/0x1890 fs/ext4/inode.c:6753
 do_page_mkwrite+0x17a/0x440 mm/memory.c:3684
 do_shared_fault mm/memory.c:5985 [inline]
 do_fault+0x3b5/0x1750 mm/memory.c:6047
 do_pte_missing mm/memory.c:4566 [inline]
 handle_pte_fault mm/memory.c:6427 [inline]
 __handle_mm_fault+0x187d/0x2a00 mm/memory.c:6565
 handle_mm_fault+0x36d/0xa20 mm/memory.c:6734
 do_user_addr_fault+0x5a3/0x12f0 arch/x86/mm/fault.c:1334
 handle_page_fault arch/x86/mm/fault.c:1474 [inline]
 exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1527
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f095de65711
RSP: 002b:00007ffcba281b70 EFLAGS: 00010202
RAX: 0000001b34464000 RBX: 0000000000000000 RCX: 000000000003fde8
RDX: 0000001b34463fff RSI: 0000000000000008 RDI: 00007f095ed45720
RBP: 00007f095ed45720 R08: 0000000000000000 R09: 00007f095e216218
R10: 00007f095ed45700 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000003
 </TASK>
INFO: task syz.0.262:7095 blocked in I/O wait for more than 145 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.262       state:D stack:27384 pid:7095  tgid:7095  ppid:5638   task_flags:0x440040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1295/0x67a0 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7283
 io_schedule+0x8a/0xf0 kernel/sched/core.c:8110
 bit_wait_io+0xd/0xe0 kernel/sched/wait_bit.c:250
 __wait_on_bit+0x65/0x180 kernel/sched/wait_bit.c:52
 out_of_line_wait_on_bit+0xdc/0x110 kernel/sched/wait_bit.c:67
 wait_on_bit_io include/linux/wait_bit.h:105 [inline]
 do_get_write_access+0x84f/0x1220 fs/jbd2/transaction.c:1113
 jbd2_journal_get_write_access+0x1d6/0x280 fs/jbd2/transaction.c:1263
 __ext4_journal_get_write_access+0x6a/0x340 fs/ext4/ext4_jbd2.c:241
 ext4_reserve_inode_write+0x1b7/0x330 fs/ext4/inode.c:6375
 __ext4_mark_inode_dirty+0x18f/0x890 fs/ext4/inode.c:6550
 ext4_dirty_inode+0xd9/0x130 fs/ext4/inode.c:6587
 __mark_inode_dirty+0x1f3/0x1720 fs/fs-writeback.c:2623
 generic_update_time fs/inode.c:2198 [inline]
 touch_atime+0x642/0x7a0 fs/inode.c:2273
 file_accessed include/linux/fs.h:2264 [inline]
 ext4_file_mmap_prepare+0x56d/0x670 fs/ext4/file.c:840
 vfs_mmap_prepare include/linux/fs.h:2076 [inline]
 call_mmap_prepare mm/vma.c:2672 [inline]
 __mmap_region+0xe98/0x2da0 mm/vma.c:2755
 mmap_region+0x527/0x620 mm/vma.c:2857
 do_mmap+0xc63/0x12f0 mm/mmap.c:560
 vm_mmap_pgoff+0x29e/0x470 mm/util.c:581
 ksys_mmap_pgoff+0x3cb/0x610 mm/mmap.c:606
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
 __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0x830 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f94ab39cbc2
RSP: 002b:00007ffda7897338 EFLAGS: 00000206 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 0000001b34264000 RCX: 00007f94ab39cbc2
RDX: 0000000000000003 RSI: 00000000003c0000 RDI: 0000001b34264000
RBP: 0000000000100001 R08: 0000000000000004 R09: 0000000000040000
R10: 0000000000100001 R11: 0000000000000206 R12: 000000000000003f
R13: 00000000000927c0 R14: 00000000000215f4 R15: 00007ffda7897610
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8e7e5420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8e7e5420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8e7e5420 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
6 locks held by kworker/u8:6/1008:
 #0: ffff888020af0940 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289
 #1: ffffc90005407d08 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290
 #2: ffff88802be4a0d8 (&type->s_umount_key#33){++++}-{4:4}, at: super_trylock_shared+0x1e/0xf0 fs/super.c:565
 #3: ffff88802be48c18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x278/0x600 mm/page-writeback.c:2571
 #4: ffff88802bf7e938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xfaa/0x13a0 fs/jbd2/transaction.c:444
 #5: ffff888076429e30 (&ei->i_data_sem){++++}-{4:4}, at: ext4_map_blocks+0x45a/0xd30 fs/ext4/inode.c:823
2 locks held by getty/5386:
 #0: ffff8880334de0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14f0 drivers/tty/n_tty.c:2211
3 locks held by syz-executor/5615:
 #0: ffff888034479448 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x11d/0x590 mm/mmap_lock.c:310
 #1: ffff88802be4a508 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x17a/0x440 mm/memory.c:3684
 #2: ffff88802bf7e938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xfaa/0x13a0 fs/jbd2/transaction.c:444
3 locks held by syz.3.261/7085:
 #0: ffff88807f470e48 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x11d/0x590 mm/mmap_lock.c:310
 #1: ffff88802be4a508 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x17a/0x440 mm/memory.c:3684
 #2: ffff88802bf7e938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xfaa/0x13a0 fs/jbd2/transaction.c:444
3 locks held by syz.2.260/7087:
 #0: ffff888079bb7588 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x11d/0x590 mm/mmap_lock.c:310
 #1: ffff88802be4a508 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x17a/0x440 mm/memory.c:3684
 #2: ffff88802bf7e938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xfaa/0x13a0 fs/jbd2/transaction.c:444
3 locks held by syz.0.262/7095:
 #0: ffff888036958f78 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:554 [inline]
 #0: ffff888036958f78 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1f5/0x470 mm/util.c:579
 #1: ffff88802be4a410 (sb_writers#4){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2264 [inline]
 #1: ffff88802be4a410 (sb_writers#4){.+.+}-{0:0}, at: ext4_file_mmap_prepare+0x56d/0x670 fs/ext4/file.c:840
 #2: ffff88802bf7e938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xfaa/0x13a0 fs/jbd2/transaction.c:444

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x141/0x190 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xcb1/0x1030 kernel/hung_task.c:561
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/05/25 18:07 upstream e7ae89a0c97c c69befb3 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task kworker/u8:NUM:NUM blocked in I/O wait for more than NUM seconds.
2026/05/23 12:15 upstream 79bd2dded182 c69befb3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task kworker/u8:NUM:NUM blocked in I/O wait for more than NUM seconds.
2026/05/22 20:47 upstream 45255ea1ca09 e16cf9f3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task kworker/u8:NUM:NUM blocked in I/O wait for more than NUM seconds.
2026/05/19 20:13 upstream ab5fce87a778 2aa09d96 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task kworker/u8:NUM:NUM blocked in I/O wait for more than NUM seconds.
2026/05/11 00:33 upstream aa54b1d27fe0 29233ece .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task kworker/u8:NUM:NUM blocked in I/O wait for more than NUM seconds.
* Struck through repros no longer work on HEAD.