INFO: task hung in mpage_prepare_extent_to_map

Status: upstream: reported on 2026/08/18 02:27
Reported-by: syzbot+4878406d96d94ffd8e6c@syzkaller.appspotmail.com
First crash: 2d20h, last: 2d20h
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in mpage_prepare_extent_to_map 1 syz done 18606 2480d 2488d 14/29 fixed on 2019/11/29 15:48
upstream INFO: task hung in mpage_prepare_extent_to_map (2) ext4 1 4 636d 639d 0/29 auto-obsoleted due to no activity on 2025/02/20 07:58
upstream INFO: task hung in mpage_prepare_extent_to_map (3) ext4 mm 1 3 492d 520d 0/29 auto-obsoleted due to no activity on 2025/07/14 01:35
linux-5.15 INFO: task hung in mpage_prepare_extent_to_map 1 1 16d 16d 0/3 upstream: reported on 2026/08/04 19:48

Sample crash report:
INFO: task kworker/u4:8:3453 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:8    state:D stack:22544 pid:3453  ppid:2      flags:0x00004000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6701
 schedule+0xbd/0x170 kernel/sched/core.c:6775
 io_schedule+0x80/0xd0 kernel/sched/core.c:9024
 folio_wait_bit_common+0x881/0xfa0 mm/filemap.c:1329
 folio_wait_writeback+0xe2/0x1e0 mm/page-writeback.c:3090
 mpage_prepare_extent_to_map+0x910/0x1d50 fs/ext4/inode.c:2482
 ext4_do_writepages+0xb46/0x3990 fs/ext4/inode.c:2674
 ext4_writepages+0x1dd/0x350 fs/ext4/inode.c:2810
 do_writepages+0x351/0x590 mm/page-writeback.c:2575
 __writeback_single_inode+0x14e/0xee0 fs/fs-writeback.c:1686
 writeback_sb_inodes+0x813/0x1020 fs/fs-writeback.c:1977
 wb_writeback+0x45e/0xbe0 fs/fs-writeback.c:2156
 wb_do_writeback fs/fs-writeback.c:2303 [inline]
 wb_workfn+0x400/0xe60 fs/fs-writeback.c:2343
 process_one_work kernel/workqueue.c:2657 [inline]
 process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734
 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
INFO: task jbd2/sda1-8:5102 blocked 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:26024 pid:5102  ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6701
 schedule+0xbd/0x170 kernel/sched/core.c:6775
 io_schedule+0x80/0xd0 kernel/sched/core.c:9024
 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:209
 __wait_on_bit+0x9f/0x2c0 kernel/sched/wait_bit.c:49
 out_of_line_wait_on_bit+0x13c/0x190 kernel/sched/wait_bit.c:64
 wait_on_buffer include/linux/buffer_head.h:373 [inline]
 jbd2_journal_commit_transaction+0x2e8d/0x5ad0 fs/jbd2/commit.c:815
 kjournald2+0x40f/0x810 fs/jbd2/journal.c:201
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
INFO: task syz-executor:5762 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:22888 pid:5762  ppid:5761   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6701
 schedule+0xbd/0x170 kernel/sched/core.c:6775
 io_schedule+0x80/0xd0 kernel/sched/core.c:9024
 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:209
 __wait_on_bit+0x9f/0x2c0 kernel/sched/wait_bit.c:49
 out_of_line_wait_on_bit+0x13c/0x190 kernel/sched/wait_bit.c:64
 wait_on_bit_io include/linux/wait_bit.h:101 [inline]
 do_get_write_access+0x5c9/0xe00 fs/jbd2/transaction.c:1096
 jbd2_journal_get_write_access+0x10c/0x140 fs/jbd2/transaction.c:1231
 __ext4_journal_get_write_access+0x208/0x6d0 fs/ext4/ext4_jbd2.c:241
 ext4_reserve_inode_write+0x205/0x2a0 fs/ext4/inode.c:5933
 __ext4_mark_inode_dirty+0x13f/0x6d0 fs/ext4/inode.c:6107
 ext4_dirty_inode+0xcb/0x110 fs/ext4/inode.c:6144
 __mark_inode_dirty+0x2cc/0xc90 fs/fs-writeback.c:2522
 generic_update_time fs/inode.c:1981 [inline]
 inode_update_time fs/inode.c:1994 [inline]
 __file_update_time fs/inode.c:2180 [inline]
 file_update_time+0x187/0x1a0 fs/inode.c:2210
 ext4_page_mkwrite+0x1f9/0x11a0 fs/ext4/inode.c:6262
 do_page_mkwrite+0x153/0x3f0 mm/memory.c:2951
 wp_page_shared mm/memory.c:3311 [inline]
 do_wp_page+0xd4d/0x34d0 mm/memory.c:3396
 handle_pte_fault mm/memory.c:5063 [inline]
 __handle_mm_fault mm/memory.c:5188 [inline]
 handle_mm_fault+0x1306/0x4a50 mm/memory.c:5353
 do_user_addr_fault+0x736/0x12d0 arch/x86/mm/fault.c:1371
 handle_page_fault arch/x86/mm/fault.c:1463 [inline]
 exc_page_fault+0x64/0x100 arch/x86/mm/fault.c:1516
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7f4c6227c662
RSP: 002b:00007ffc0eed2040 EFLAGS: 00010246
RAX: 00007f4c6009c000 RBX: 000055558b34a820 RCX: 0000000000000000
RDX: 000000000000134f RSI: 000055558b348aa8 RDI: 0000000000000001
RBP: 00007ffc0eed2540 R08: 000055558b348ab0 R09: 0000000000000092
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffc0eed2380
R13: 00007ffc0eed2170 R14: 585858582e7a7973 R15: 00007ffc0eed20c0
 </TASK>
INFO: task syz-executor:7585 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21800 pid:7585  ppid:7555   flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6701
 schedule+0xbd/0x170 kernel/sched/core.c:6775
 io_schedule+0x80/0xd0 kernel/sched/core.c:9024
 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:209
 __wait_on_bit+0x9f/0x2c0 kernel/sched/wait_bit.c:49
 out_of_line_wait_on_bit+0x13c/0x190 kernel/sched/wait_bit.c:64
 wait_on_bit_io include/linux/wait_bit.h:101 [inline]
 do_get_write_access+0x5c9/0xe00 fs/jbd2/transaction.c:1096
 jbd2_journal_get_write_access+0x10c/0x140 fs/jbd2/transaction.c:1231
 __ext4_journal_get_write_access+0x208/0x6d0 fs/ext4/ext4_jbd2.c:241
 __ext4_new_inode+0x13f2/0x3ad0 fs/ext4/ialloc.c:1099
 ext4_mkdir+0x40b/0xc90 fs/ext4/namei.c:3066
 vfs_mkdir+0x2a5/0x470 fs/namei.c:4168
 do_mkdirat+0x1dc/0x450 fs/namei.c:4191
 __do_sys_mkdirat fs/namei.c:4206 [inline]
 __se_sys_mkdirat fs/namei.c:4204 [inline]
 __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4204
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f434999cf47
RSP: 002b:00007ffd1ee0e328 EFLAGS: 00000202 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f4349a34a68 RCX: 00007f434999cf47
RDX: 00000000000001ff RSI: 00007f4349a34a68 RDI: 00000000ffffff9c
RBP: 00007f4349c267b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008
R13: 0000000000000003 R14: 00007ffd1ee0e598 R15: 0000000000000000
 </TASK>
INFO: task syz.2.466:7634 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.466       state:D stack:28840 pid:7634  ppid:5778   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6701
 schedule+0xbd/0x170 kernel/sched/core.c:6775
 io_schedule+0x80/0xd0 kernel/sched/core.c:9024
 folio_wait_bit_common+0x881/0xfa0 mm/filemap.c:1329
 folio_wait_writeback+0xe2/0x1e0 mm/page-writeback.c:3090
 __filemap_fdatawait_range+0x171/0x3c0 mm/filemap.c:525
 filemap_fdatawait_keep_errors+0x31/0xd0 mm/filemap.c:620
 wait_sb_inodes fs/fs-writeback.c:2710 [inline]
 sync_inodes_sb+0x7ba/0xa10 fs/fs-writeback.c:2832
 iterate_supers+0xb2/0x170 fs/super.c:979
 ksys_sync+0xa1/0x170 fs/sync.c:102
 __ia32_sys_sync+0xe/0x20 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fd79c19e0d9
RSP: 002b:00007fd79d098028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fd79c425fa0 RCX: 00007fd79c19e0d9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fd79c425fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd79c426038 R14: 00007fd79c425fa0 R15: 00007ffdbdd430c8
 </TASK>
INFO: task syz.2.466:7636 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.466       state:D stack:29000 pid:7636  ppid:5778   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6701
 schedule+0xbd/0x170 kernel/sched/core.c:6775
 wb_wait_for_completion+0x173/0x2a0 fs/fs-writeback.c:192
 sync_inodes_sb+0x1c9/0xa10 fs/fs-writeback.c:2829
 iterate_supers+0xb2/0x170 fs/super.c:979
 ksys_sync+0xa1/0x170 fs/sync.c:102
 __ia32_sys_sync+0xe/0x20 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fd79c19e0d9
RSP: 002b:00007fd79d077028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fd79c426090 RCX: 00007fd79c19e0d9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fd79c426090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd79c426128 R14: 00007fd79c426090 R15: 00007ffdbdd430c8
 </TASK>
INFO: task syz.5.476:7676 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.476       state:D stack:26696 pid:7676  ppid:6823   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6701
 schedule+0xbd/0x170 kernel/sched/core.c:6775
 io_schedule+0x80/0xd0 kernel/sched/core.c:9024
 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:209
 __wait_on_bit+0x9f/0x2c0 kernel/sched/wait_bit.c:49
 out_of_line_wait_on_bit+0x13c/0x190 kernel/sched/wait_bit.c:64
 wait_on_bit_io include/linux/wait_bit.h:101 [inline]
 do_get_write_access+0x5c9/0xe00 fs/jbd2/transaction.c:1096
 jbd2_journal_get_write_access+0x10c/0x140 fs/jbd2/transaction.c:1231
 __ext4_journal_get_write_access+0x208/0x6d0 fs/ext4/ext4_jbd2.c:241
 ext4_reserve_inode_write+0x205/0x2a0 fs/ext4/inode.c:5933
 __ext4_mark_inode_dirty+0x13f/0x6d0 fs/ext4/inode.c:6107
 ext4_dirty_inode+0xcb/0x110 fs/ext4/inode.c:6144
 __mark_inode_dirty+0x2cc/0xc90 fs/fs-writeback.c:2522
 generic_update_time fs/inode.c:1981 [inline]
 inode_update_time fs/inode.c:1994 [inline]
 __file_update_time fs/inode.c:2180 [inline]
 file_update_time+0x187/0x1a0 fs/inode.c:2210
 ext4_page_mkwrite+0x1f9/0x11a0 fs/ext4/inode.c:6262
 do_page_mkwrite+0x153/0x3f0 mm/memory.c:2951
 do_shared_fault mm/memory.c:4717 [inline]
 do_fault mm/memory.c:4779 [inline]
 do_pte_missing mm/memory.c:3689 [inline]
 handle_pte_fault mm/memory.c:5047 [inline]
 __handle_mm_fault mm/memory.c:5188 [inline]
 handle_mm_fault+0x1a2c/0x4a50 mm/memory.c:5353
 do_user_addr_fault+0x736/0x12d0 arch/x86/mm/fault.c:1371
 handle_page_fault arch/x86/mm/fault.c:1463 [inline]
 exc_page_fault+0x64/0x100 arch/x86/mm/fault.c:1516
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7f5dc8c6ba23
RSP: 002b:00007ffdb7f9a570 EFLAGS: 00010246
RAX: 00000000003ffde8 RBX: 0000000000000000 RCX: 0000001b2ea64000
RDX: 0000001b2ea24000 RSI: 0000000000400000 RDI: 00007f5dc8fe0708
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffdb7f9a800
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
3 locks held by kworker/u4:8/3453:
 #0: ffff88801b64bd38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff88801b64bd38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc9000cb07d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc9000cb07d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #2: ffff88807e850c58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1768 [inline]
 #2: ffff88807e850c58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1a4/0x350 fs/ext4/inode.c:2809
1 lock held by syslogd/5122:
 #0: ffff8880b8e3c298 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559
2 locks held by getty/5530:
 #0: ffff88803129a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217
3 locks held by syz-executor/5762:
 #0: ffff8880305f3120 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline]
 #0: ffff8880305f3120 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5380 [inline]
 #0: ffff8880305f3120 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5440
 #1: ffff88807e84e510 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1633 [inline]
 #1: ffff88807e84e510 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1737 [inline]
 #1: ffff88807e84e510 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1e2/0x11a0 fs/ext4/inode.c:6261
 #2: ffff88807e840990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f3f/0x2170 fs/jbd2/transaction.c:448
2 locks held by kworker/u4:18/6303:
3 locks held by syz-executor/7585:
 #0: ffff88807e84e418 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:412
 #1: ffff88805f458410 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:839 [inline]
 #1: ffff88805f458410 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: filename_create+0x20f/0x450 fs/namei.c:3937
 #2: ffff88807e840990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f3f/0x2170 fs/jbd2/transaction.c:448
2 locks held by syz.2.466/7634:
 #0: ffff88807e84e0e0 (&type->s_umount_key#32){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff88807e84e0e0 (&type->s_umount_key#32){++++}-{3:3}, at: super_lock+0x189/0x390 fs/super.c:117
 #1: ffff88807e84e948 (&s->s_sync_lock){+.+.}-{3:3}, at: wait_sb_inodes fs/fs-writeback.c:2649 [inline]
 #1: ffff88807e84e948 (&s->s_sync_lock){+.+.}-{3:3}, at: sync_inodes_sb+0x26f/0xa10 fs/fs-writeback.c:2832
2 locks held by syz.2.466/7636:
 #0: ffff88807e84e0e0 (&type->s_umount_key#32){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff88807e84e0e0 (&type->s_umount_key#32){++++}-{3:3}, at: super_lock+0x189/0x390 fs/super.c:117
 #1: ffff888024746820 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
 #1: ffff888024746820 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1ad/0xa10 fs/fs-writeback.c:2827
3 locks held by syz.5.476/7676:
 #0: ffff88802c59d720 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline]
 #0: ffff88802c59d720 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5380 [inline]
 #0: ffff88802c59d720 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5440
 #1: ffff88807e84e510 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1633 [inline]
 #1: ffff88807e84e510 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1737 [inline]
 #1: ffff88807e84e510 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1e2/0x11a0 fs/ext4/inode.c:6261
 #2: ffff88807e840990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f3f/0x2170 fs/jbd2/transaction.c:448

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

NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xf59/0xfa0 kernel/hung_task.c:379
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 7420 Comm: ipvs-e:5:0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:__schedule+0x803/0x4660 kernel/sched/core.c:-1
Code: f7 4c 8b 64 24 10 4c 89 23 48 8b 9c 24 b8 00 00 00 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 f0 dc 48 f7 48 ff 03 <48> 8b 84 24 98 00 00 00 66 42 c7 44 28 06 00 00 42 c6 44 28 08 00
RSP: 0018:ffffc9000b67f8c0 EFLAGS: 00000006
RAX: 1ffff110043eb86e RBX: ffff888021f5c370 RCX: ffffffff8a9717e2
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff888021f5bc00
RBP: ffffc9000b67fad0 R08: ffff888021f5bc07 R09: 1ffff110043eb780
R10: dffffc0000000000 R11: ffffed10043eb781 R12: ffff88807bf4bc00
R13: dffffc0000000000 R14: ffff888021f5bc00 R15: ffff8880b8e3c280
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000556ce7700168 CR3: 000000000cf32000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 schedule+0xbd/0x170 kernel/sched/core.c:6775
 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
 ip_vs_estimation_kthread+0x2b35/0x3a40 net/netfilter/ipvs/ip_vs_est.c:208
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/18 02:27 linux-6.6.y d27334b2888c 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: task hung in mpage_prepare_extent_to_map
* Struck through repros no longer work on HEAD.