INFO: task kworker/u4:1:12 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:1    state:D stack:21912 pid:12    ppid:2      flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:0)
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
 __lock_metapage fs/jfs/jfs_metapage.c:50 [inline]
 lock_metapage+0x1f8/0x320 fs/jfs/jfs_metapage.c:64
 __get_metapage+0x4cd/0xfa0 fs/jfs/jfs_metapage.c:639
 xtSplitPage+0x268/0x2110 fs/jfs/jfs_xtree.c:974
 xtSplitUp+0x33f/0x1f60 fs/jfs/jfs_xtree.c:771
 xtInsert+0x415/0xe80 fs/jfs/jfs_xtree.c:593
 extAlloc+0xac1/0x1010 fs/jfs/jfs_extent.c:150
 jfs_get_block+0x352/0xad0 fs/jfs/inode.c:254
 __mpage_writepage+0x828/0x1de0 fs/mpage.c:559
 write_cache_pages+0x724/0x1290 mm/page-writeback.c:2496
 mpage_writepages+0x103/0x1c0 fs/mpage.c:679
 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 syz-executor:5890 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:21800 pid:5890  ppid:1      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
 sync_filesystem+0x171/0x220 fs/sync.c:64
 generic_shutdown_super+0x6f/0x2b0 fs/super.c:666
 kill_block_super+0x44/0x90 fs/super.c:1668
 deactivate_locked_super+0x97/0x100 fs/super.c:481
 cleanup_mnt+0x3d7/0x460 fs/namespace.c:1259
 task_work_run+0x1d4/0x260 kernel/task_work.c:245
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:180
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:213
 __syscall_exit_to_user_mode_work kernel/entry/common.c:294 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:305
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7feace99f397
RSP: 002b:00007ffe3a3325d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007feacea344bb RCX: 00007feace99f397
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe3a332690
RBP: 00007ffe3a332690 R08: 00007ffe3a333690 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe3a333720
R13: 00007feacea344bb R14: 0000000000019d93 R15: 00007ffe3a333760
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/u4:0/11:
 #0: ffff88801ce6c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff88801ce6c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc90000107d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc90000107d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #2: ffff88805e422f78 (&jfs_ip->rdwrlock#2){++++}-{3:3}, at: jfs_get_block+0x14f/0xad0 fs/jfs/inode.c:219
 #3: ffff88805e423008 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: extAlloc+0x131/0x1010 fs/jfs/jfs_extent.c:86
4 locks held by kworker/u4:1/12:
 #0: ffff88801ce6c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff88801ce6c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc90000117d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc90000117d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #2: ffff88807236b8b8 (&jfs_ip->rdwrlock#2){++++}-{3:3}, at: jfs_get_block+0x14f/0xad0 fs/jfs/inode.c:219
 #3: ffff88807236b948 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: extAlloc+0x131/0x1010 fs/jfs/jfs_extent.c:86
1 lock held by khungtaskd/29:
 #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6635
4 locks held by kworker/u4:2/42:
 #0: ffff88801ce6c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff88801ce6c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc90000b2fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc90000b2fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #2: ffff88805e70d478 (&jfs_ip->rdwrlock#2){++++}-{3:3}, at: jfs_get_block+0x14f/0xad0 fs/jfs/inode.c:219
 #3: ffff88805e70d508 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: extAlloc+0x131/0x1010 fs/jfs/jfs_extent.c:86
4 locks held by kworker/u4:3/49:
 #0: ffff88801ce6c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff88801ce6c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc90000b9fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc90000b9fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #2: ffff88805e6a8a78 (&jfs_ip->rdwrlock#2){++++}-{3:3}, at: jfs_get_block+0x14f/0xad0 fs/jfs/inode.c:219
 #3: ffff88805e6a8b08 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: extAlloc+0x131/0x1010 fs/jfs/jfs_extent.c:86
4 locks held by kworker/u4:5/1020:
 #0: ffff88801ce6c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff88801ce6c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc900043afd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc900043afd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #2: ffff88805e7093b8 (&jfs_ip->rdwrlock#2){++++}-{3:3}, at: jfs_get_block+0x14f/0xad0 fs/jfs/inode.c:219
 #3: ffff88805e709448 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: extAlloc+0x131/0x1010 fs/jfs/jfs_extent.c:86
4 locks held by kworker/u4:6/1100:
 #0: ffff88801ce6c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff88801ce6c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc900047afd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc900047afd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #2: ffff88805e427038 (&jfs_ip->rdwrlock#2){++++}-{3:3}, at: jfs_get_block+0x14f/0xad0 fs/jfs/inode.c:219
 #3: ffff88805e4270c8 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: extAlloc+0x131/0x1010 fs/jfs/jfs_extent.c:86
4 locks held by kworker/u4:7/3428:
 #0: ffff88801ce6c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff88801ce6c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc9000c707d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc9000c707d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #2: ffff88805e6acb38 (&jfs_ip->rdwrlock#2){++++}-{3:3}, at: jfs_get_block+0x14f/0xad0 fs/jfs/inode.c:219
 #3: ffff88805e6acbc8 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: extAlloc+0x131/0x1010 fs/jfs/jfs_extent.c:86
2 locks held by getty/5529:
 #0: ffff88802d2ca0a0 (&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
2 locks held by syz-executor/5890:
 #0: ffff8880267160e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff8880267160e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff8880267160e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
 #1: ffff8880217e0820 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
 #1: ffff8880217e0820 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1ad/0xa10 fs/fs-writeback.c:2827
2 locks held by syz-executor/5935:
 #0: ffff888077e3a0e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff888077e3a0e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff888077e3a0e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
 #1: ffff8880217e6820 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
 #1: ffff8880217e6820 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1ad/0xa10 fs/fs-writeback.c:2827
2 locks held by syz-executor/5956:
 #0: ffff888076d980e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff888076d980e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff888076d980e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
 #1: ffff8880217f4820 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
 #1: ffff8880217f4820 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1ad/0xa10 fs/fs-writeback.c:2827
2 locks held by syz-executor/5973:
 #0: ffff88807c5460e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff88807c5460e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff88807c5460e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
 #1: ffff888021802820 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
 #1: ffff888021802820 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1ad/0xa10 fs/fs-writeback.c:2827
4 locks held by kworker/u4:9/5987:
 #0: ffff88801ce6c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff88801ce6c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc90003547d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc90003547d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #2: ffff8880768e9cf8 (&jfs_ip->rdwrlock#2){++++}-{3:3}, at: jfs_get_block+0x14f/0xad0 fs/jfs/inode.c:219
 #3: ffff8880768e9d88 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: extAlloc+0x131/0x1010 fs/jfs/jfs_extent.c:86
3 locks held by kworker/u4:10/5989:
2 locks held by syz-executor/5991:
 #0: ffff8880764960e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff8880764960e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff8880764960e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
 #1: ffff888021810820 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
 #1: ffff888021810820 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1ad/0xa10 fs/fs-writeback.c:2827
2 locks held by syz-executor/6019:
 #0: ffff88805efe00e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff88805efe00e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff88805efe00e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
 #1: ffff888021816820 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
 #1: ffff888021816820 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1ad/0xa10 fs/fs-writeback.c:2827
2 locks held by syz-executor/6041:
 #0: ffff888079af00e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff888079af00e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff888079af00e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
 #1: ffff88814170c820 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
 #1: ffff88814170c820 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1ad/0xa10 fs/fs-writeback.c:2827
2 locks held by syz-executor/6065:
 #0: ffff888079ad00e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff888079ad00e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff888079ad00e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
 #1: ffff88814171a820 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
 #1: ffff88814171a820 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1ad/0xa10 fs/fs-writeback.c:2827
2 locks held by syz-executor/6087:
 #0: ffff888054fe80e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff888054fe80e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff888054fe80e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
 #1: ffff888141720820 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
 #1: ffff888141720820 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1ad/0xa10 fs/fs-writeback.c:2827
4 locks held by kworker/u4:14/6099:
 #0: ffff88801ce6c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff88801ce6c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc90003977d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc90003977d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #2: ffff8880768eddb8 (&jfs_ip->rdwrlock#2){++++}-{3:3}, at: jfs_get_block+0x14f/0xad0 fs/jfs/inode.c:219
 #3: ffff8880768ede48 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: extAlloc+0x131/0x1010 fs/jfs/jfs_extent.c:86

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

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: 5128 Comm: klogd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:check_kcov_mode kernel/kcov.c:189 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x36/0x60 kernel/kcov.c:212
Code: a0 2c 7c 7e 65 8b 15 a1 2c 7c 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 24 16 00 00 00 74 2c 8b 91 00 16 00 00 <83> fa 02 75 21 48 8b 91 08 16 00 00 48 8b 32 48 8d 7e 01 8b 89 04
RSP: 0018:ffffc90003297390 EFLAGS: 00000246
RAX: ffffffff813bbc29 RBX: ffffffff8f199be2 RCX: ffff88807ef85a00
RDX: 0000000000000000 RSI: ffffffff8cfa0900 RDI: 0000000000000005
RBP: ffffc900032974b8 R08: ffff88807ef85a00 R09: 0000000000000008
R10: 0000000000000009 R11: 0000000000000000 R12: ffffffff8f199be6
R13: ffffc90003297468 R14: 0000000000000005 R15: dffffc0000000000
FS:  00007f8e04b99c80(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005567aa2b4660 CR3: 00000000303af000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 unwind_next_frame+0x859/0x2990 arch/x86/kernel/unwind_orc.c:517
 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 ____kasan_kmalloc mm/kasan/common.c:375 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384
 kasan_kmalloc include/linux/kasan.h:198 [inline]
 __do_kmalloc_node mm/slab_common.c:1007 [inline]
 __kmalloc_node_track_caller+0xb4/0x230 mm/slab_common.c:1027
 kmalloc_reserve+0x116/0x240 net/core/skbuff.c:584
 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:653
 alloc_skb include/linux/skbuff.h:1316 [inline]
 alloc_skb_with_frags+0xcd/0x7a0 net/core/skbuff.c:6355
 sock_alloc_send_pskb+0x883/0x9a0 net/core/sock.c:2829
 unix_dgram_sendmsg+0x5a9/0x16e0 net/unix/af_unix.c:2003
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x4a9/0x6b0 net/socket.c:2201
 __do_sys_sendto net/socket.c:2213 [inline]
 __se_sys_sendto net/socket.c:2209 [inline]
 __x64_sys_sendto+0xde/0xf0 net/socket.c:2209
 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: 0033:0x7f8e04ce9407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffc7d17e0d0 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f8e04b99c80 RCX: 00007f8e04ce9407
RDX: 0000000000000050 RSI: 00007ffc7d17e210 RDI: 0000000000000003
RBP: 00007ffc7d17e640 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffc7d17e658
R13: 00007ffc7d17e210 R14: 0000000000000035 R15: 00007ffc7d17e210
 </TASK>