syzbot

INFO: task kworker/u8:5:1086 blocked for more than 143 seconds.
      Not tainted 6.12.0-rc6-syzkaller-00077-g2e1b3cc9d7f7 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:5    state:D stack:23920 pid:1086  tgid:1086  ppid:2      flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5328 [inline]
 __schedule+0x17fa/0x4bd0 kernel/sched/core.c:6690
 __schedule_loop kernel/sched/core.c:6767 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6782
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6839
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752
 jfs_commit_inode+0x24a/0x590 fs/jfs/inode.c:102
 jfs_write_inode+0x143/0x220 fs/jfs/inode.c:132
 write_inode fs/fs-writeback.c:1503 [inline]
 __writeback_single_inode+0x711/0x10d0 fs/fs-writeback.c:1723
 writeback_sb_inodes+0x80c/0x1370 fs/fs-writeback.c:1954
 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2025
 wb_writeback+0x42f/0xbd0 fs/fs-writeback.c:2136
 wb_check_background_flush fs/fs-writeback.c:2206 [inline]
 wb_do_writeback fs/fs-writeback.c:2294 [inline]
 wb_workfn+0xc58/0x1090 fs/fs-writeback.c:2321
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720
4 locks held by kworker/u8:5/1086:
 #0: ffff8881416cb148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff8881416cb148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc90004e17d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc90004e17d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffff88807b26e0e0 (&type->s_umount_key#44){.+.+}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562
 #3: ffff888077bf8b00 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x24a/0x590 fs/jfs/inode.c:102
2 locks held by getty/5596:
 #0: ffff888034b4a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211
4 locks held by syz-executor447/5852:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc6-syzkaller-00077-g2e1b3cc9d7f7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xff4/0x1040 kernel/hung_task.c:379
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5852 Comm: syz-executor447 Not tainted 6.12.0-rc6-syzkaller-00077-g2e1b3cc9d7f7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:dtSplitRoot+0x8de/0x1930
Code: e8 87 de 69 fe 48 c1 e3 05 4c 01 e3 49 89 dc 49 c1 ec 03 43 0f b6 04 2c 84 c0 75 15 44 0f b6 3b 45 84 ff 78 34 e8 62 de 69 fe <4c> 8b 64 24 10 eb ba 89 d9 80 e1 07 38 c1 7c e2 48 89 df e8 2a 80
RSP: 0018:ffffc90003bef4a0 EFLAGS: 00000293
RAX: ffffffff832afb9e RBX: ffff888074e3f000 RCX: ffff88807b319e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000000000ff
RBP: ffffc90003bef690 R08: ffffffff832afb70 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1100e9c7e00
R13: dffffc0000000000 R14: ffff888077bf8d68 R15: 0000000000000000
FS:  0000555562b2c380(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e89d07d600 CR3: 00000000781da000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 dtSplitUp fs/jfs/jfs_dtree.c:992 [inline]
 dtInsert+0x12cd/0x6c10 fs/jfs/jfs_dtree.c:870
 jfs_create+0x7ba/0xbb0 fs/jfs/namei.c:137
 vfs_create+0x23c/0x3d0 fs/namei.c:3294
 do_mknodat+0x447/0x5b0 fs/namei.c:4185
 __do_sys_mknod fs/namei.c:4218 [inline]
 __se_sys_mknod fs/namei.c:4216 [inline]
 __x64_sys_mknod+0x8c/0xa0 fs/namei.c:4216
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb8d768fa59
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcf7cf89d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000085
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb8d768fa59
RDX: 0000000000000701 RSI: 0000000000000000 RDI: 0000000020000000
RBP: 00007fb8d77095f0 R08: 000000000000618e R09: 0000555562b2d4c0
R10: 00007ffcf7cf88a0 R11: 0000000000000246 R12: 00007ffcf7cf8a00
R13: 00007ffcf7cf8c28 R14: 431bde82d7b634db R15: 00007fb8d76d803b
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.315 msecs