INFO: task kworker/u32:NUM:NUM blocked in I/O wait for more than NUM seconds.

ID	Workflow	Result	Correct	Bug	Created	Started	Finished	Revision
f11f94f6	assessment-security	DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌	❓	INFO: task kworker/u32:NUM:NUM blocked in I/O wait for more than NUM seconds.	2026/06/01 14:11	2026/06/01 14:11	2026/06/01 15:09	386cc6da

INFO: task kworker/u32:2:46 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u32:2 state:D stack:24840 pid:46 tgid:46 ppid:2 task_flags:0x4248160 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_mb_mark_context+0x179/0xdb0 fs/ext4/mballoc.c:4111 ext4_mb_mark_diskspace_used+0x472/0x800 fs/ext4/mballoc.c:4240 ext4_mb_new_blocks+0x93d/0x4c60 fs/ext4/mballoc.c:6328 ext4_ext_map_blocks+0x1c74/0x5930 fs/ext4/extents.c:4461 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/sda1-8:5110 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:jbd2/sda1-8 state:D stack:25720 pid:5110 tgid:5110 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.2.343:7067 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.343 state:D stack:26216 pid:7067 tgid:7067 ppid:5740 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+0xe98/0x2dd0 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+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd8c239cbc2 RSP: 002b:00007ffc17417508 EFLAGS: 00000206 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 0000001b33364000 RCX: 00007fd8c239cbc2 RDX: 0000000000000003 RSI: 00000000003c0000 RDI: 0000001b33364000 RBP: 0000000000100001 R08: 0000000000000004 R09: 0000000000040000 R10: 0000000000100001 R11: 0000000000000206 R12: 0000000000000058 R13: 00000000000927c0 R14: 000000000001357c R15: 00007ffc174177e0 </TASK> INFO: task syz.1.344:7068 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.344 state:D stack:27600 pid:7068 tgid:7068 ppid:5743 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+0xe98/0x2dd0 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+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7a3c99cbc2 RSP: 002b:00007ffde6352238 EFLAGS: 00000206 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 0000001b33264000 RCX: 00007f7a3c99cbc2 RDX: 0000000000000003 RSI: 00000000003c0000 RDI: 0000001b33264000 RBP: 0000000000100001 R08: 0000000000000004 R09: 0000000000040000 R10: 0000000000100001 R11: 0000000000000206 R12: 000000000000003f R13: 00000000000927c0 R14: 000000000001368d R15: 00007ffde6352510 </TASK> INFO: task syz.3.345:7069 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.345 state:D stack:27600 pid:7069 tgid:7069 ppid:5745 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+0xe98/0x2dd0 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+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f470679cbc2 RSP: 002b:00007ffea3648948 EFLAGS: 00000206 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 0000001b33464000 RCX: 00007f470679cbc2 RDX: 0000000000000003 RSI: 00000000003c0000 RDI: 0000001b33464000 RBP: 0000000000100001 R08: 0000000000000004 R09: 0000000000040000 R10: 0000000000100001 R11: 0000000000000206 R12: 000000000000005d R13: 00000000000927c0 R14: 000000000001325f R15: 00007ffea3648c20 </TASK> INFO: task syz.0.346:7070 blocked in I/O wait for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.346 state:D stack:28456 pid:7070 tgid:7070 ppid:5737 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+0x37b/0xa30 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: 0033:0x7f915106a903 RSP: 002b:00007ffdfe1654d0 EFLAGS: 00010246 RAX: 000000000003fde8 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000001b33124000 RSI: 0000000000040000 RDI: 00007f91513db710 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffdfe165760 </TASK> Showing all locks held in the system: 1 lock held by khungtaskd/41: #0: ffffffff8e7e5620 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e7e5620 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e7e5620 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 6 locks held by kworker/u32:2/46: #0: ffff88801d355940 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc900007efd08 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 #2: ffff88802d08e0d8 (&type->s_umount_key#55){++++}-{4:4}, at: super_trylock_shared+0x1e/0xf0 fs/super.c:565 #3: ffff888038abcc18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x278/0x600 mm/page-writeback.c:2571 #4: ffff888038aba938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xfaa/0x13a0 fs/jbd2/transaction.c:444 #5: ffff888040909e18 (&ei->i_data_sem){++++}-{4:4}, at: ext4_map_blocks+0x45a/0xd30 fs/ext4/inode.c:823 2 locks held by kworker/u33:1/5098: #0: ffff888029225140 ((wq_completion)nbd1-recv){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc90027097d08 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 2 locks held by getty/5540: #0: ffff888038ab30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900033732e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14f0 drivers/tty/n_tty.c:2211 3 locks held by syz-executor/5649: #0: ffff88801b8d3438 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:611 [inline] #0: ffff88801b8d3438 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/mmap_lock.c:441 [inline] #0: ffff88801b8d3438 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x35/0x6f0 mm/mmap_lock.c:501 #1: ffff88802d08e508 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x17a/0x440 mm/memory.c:3684 #2: ffff888038aba938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xfaa/0x13a0 fs/jbd2/transaction.c:444 2 locks held by kworker/u33:2/5739: #0: ffff888029225140 ((wq_completion)nbd1-recv){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc90003e4fd08 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 2 locks held by kworker/u33:6/5751: #0: ffff888029225140 ((wq_completion)nbd1-recv){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc90003e6fd08 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 3 locks held by syz.2.343/7067: #0: ffff8880402527f8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:554 [inline] #0: ffff8880402527f8 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1f5/0x470 mm/util.c:579 #1: ffff88802d08e410 (sb_writers#5){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2264 [inline] #1: ffff88802d08e410 (sb_writers#5){.+.+}-{0:0}, at: ext4_file_mmap_prepare+0x56d/0x670 fs/ext4/file.c:840 #2: ffff888038aba938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xfaa/0x13a0 fs/jbd2/transaction.c:444 3 locks held by syz.1.344/7068: #0: ffff888022cf4078 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:554 [inline] #0: ffff888022cf4078 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1f5/0x470 mm/util.c:579 #1: ffff88802d08e410 (sb_writers#5){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2264 [inline] #1: ffff88802d08e410 (sb_writers#5){.+.+}-{0:0}, at: ext4_file_mmap_prepare+0x56d/0x670 fs/ext4/file.c:840 #2: ffff888038aba938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xfaa/0x13a0 fs/jbd2/transaction.c:444 3 locks held by syz.3.345/7069: #0: ffff88802efd4cb8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:554 [inline] #0: ffff88802efd4cb8 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1f5/0x470 mm/util.c:579 #1: ffff88802d08e410 (sb_writers#5){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2264 [inline] #1: ffff88802d08e410 (sb_writers#5){.+.+}-{0:0}, at: ext4_file_mmap_prepare+0x56d/0x670 fs/ext4/file.c:840 #2: ffff888038aba938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xfaa/0x13a0 fs/jbd2/transaction.c:444 3 locks held by syz.0.346/7070: #0: ffff88803518b5c8 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x11d/0x590 mm/mmap_lock.c:310 #1: ffff88802d08e508 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x17a/0x440 mm/memory.c:3684 #2: ffff888038aba938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xfaa/0x13a0 fs/jbd2/transaction.c:444 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 41 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 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> Sending NMI from CPU 1 to CPUs 0,2-3: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: 95 94 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 03 41 24 00 fb f4 <e9> fc 43 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e407e00 EFLAGS: 00000206 RAX: 000000000013f5f3 RBX: ffffffff8e4955c0 RCX: ffffffff8b875285 RDX: 0000000000000000 RSI: ffffffff8df0b1c4 RDI: ffffffff8c1c4480 RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed100d4867b5 R10: ffff88806a433dab R11: 0000000000000000 R12: 0000000000000000 R13: fffffbfff1c92ab8 R14: 0000000000000000 R15: ffffffff90d6d350 FS: 0000000000000000(0000) GS:ffff8880d6390000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055fd179a8660 CR3: 000000000e596000 CR4: 0000000000352ef0 Call Trace: <TASK> arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x464/0x590 kernel/sched/idle.c:352 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:451 rest_init+0x251/0x260 init/main.c:762 start_kernel+0x484/0x490 init/main.c:1220 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x12b/0x130 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148 </TASK> NMI backtrace for cpu 3 CPU: 3 UID: 0 PID: 0 Comm: swapper/3 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: 95 94 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 03 41 24 00 fb f4 <e9> fc 43 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197df0 EFLAGS: 00000206 RAX: 00000000000c497d RBX: ffff88801eac2540 RCX: ffffffff8b875285 RDX: 0000000000000000 RSI: ffffffff8df0b1c4 RDI: ffffffff8c1c4480 RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed100d4e67b5 R10: ffff88806a733dab R11: 0000000000000000 R12: 0000000000000003 R13: ffffed1003d584a8 R14: 0000000000000003 R15: ffffffff90d6d350 FS: 0000000000000000(0000) GS:ffff8880d6690000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055fd179a7028 CR3: 000000000e596000 CR4: 0000000000352ef0 Call Trace: <TASK> arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x464/0x590 kernel/sched/idle.c:352 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:451 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x148 </TASK> NMI backtrace for cpu 2 CPU: 2 UID: 0 PID: 0 Comm: swapper/2 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: 95 94 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 03 41 24 00 fb f4 <e9> fc 43 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000187df0 EFLAGS: 00000206 RAX: 0000000000148bdb RBX: ffff88801eac4a80 RCX: ffffffff8b875285 RDX: 0000000000000000 RSI: ffffffff8df0b1c4 RDI: ffffffff8c1c4480 RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed100d4c67b5 R10: ffff88806a633dab R11: 0000000000000000 R12: 0000000000000002 R13: ffffed1003d58950 R14: 0000000000000002 R15: ffffffff90d6d350 FS: 0000000000000000(0000) GS:ffff8880d6590000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055fd179a8660 CR3: 000000002d5a7000 CR4: 0000000000352ef0 Call Trace: <TASK> arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x464/0x590 kernel/sched/idle.c:352 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:451 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x148 </TASK> ---------------- Code disassembly (best guess): 0: 95 xchg %eax,%ebp 1: 94 xchg %eax,%esp 2: 02 c3 add %bl,%al 4: cc int3 5: cc int3 6: cc int3 7: cc int3 8: 0f 1f 00 nopl (%rax) b: 90 nop c: 90 nop d: 90 nop e: 90 nop f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: f3 0f 1e fa endbr64 1f: eb 07 jmp 0x28 21: 0f 00 2d 03 41 24 00 verw 0x244103(%rip) # 0x24412b 28: fb sti 29: f4 hlt * 2a: e9 fc 43 03 00 jmp 0x3442b <-- trapping instruction 2f: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) 36: 00 00 00 39: 66 90 xchg %ax,%ax 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop 3f: 90 nop

Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Assets (help?)	Manager	Title
2026/05/27 11:40	upstream	eb3f4b7426cf	cd9726af	.config	console log	report	info	[disk image (non-bootable)] [vmlinux] [kernel image]	ci-qemu-upstream	INFO: task kworker/u32:NUM:NUM blocked in I/O wait for more than NUM seconds.
2026/05/27 04:51	upstream	d60ec36cab33	2b01f00e	.config	console log	report	info	[disk image (non-bootable)] [vmlinux] [kernel image]	ci-qemu-upstream	INFO: task kworker/u32:NUM:NUM blocked in I/O wait for more than NUM seconds.
2026/05/24 21:05	upstream	4cbfe4502e3d	c69befb3	.config	console log	report	info	[disk image (non-bootable)] [vmlinux] [kernel image]	ci-qemu-upstream	INFO: task kworker/u32:NUM:NUM blocked in I/O wait for more than NUM seconds.
2026/05/24 06:42	upstream	eed108edc117	c69befb3	.config	console log	report	info	[disk image (non-bootable)] [vmlinux] [kernel image]	ci-qemu-upstream	INFO: task kworker/u32:NUM:NUM blocked in I/O wait for more than NUM seconds.
2026/05/18 07:40	upstream	e5d505e3664b	de5aae85	.config	console log	report	info	[disk image (non-bootable)] [vmlinux] [kernel image]	ci-qemu-upstream	INFO: task kworker/u32:NUM:NUM blocked in I/O wait for more than NUM seconds.
2026/05/16 22:29	upstream	6916d5703ddf	de5aae85	.config	console log	report	info	[disk image (non-bootable)] [vmlinux] [kernel image]	ci-qemu-upstream	INFO: task kworker/u32:NUM:NUM blocked in I/O wait for more than NUM seconds.
2026/05/15 13:54	upstream	70eda68668d1	9cd3beaa	.config	console log	report	info	[disk image (non-bootable)] [vmlinux] [kernel image]	ci-qemu-upstream	INFO: task kworker/u32:NUM:NUM blocked in I/O wait for more than NUM seconds.