syzbot

INFO: task kworker/u4:2:154 blocked for more than 143 seconds.
      Not tainted 5.15.175-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:2    state:D stack:19488 pid:  154 ppid:     2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 schedule+0x11b/0x1f0 kernel/sched/core.c:6456
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6515
 __mutex_lock_common+0xe34/0x25a0 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 jfs_commit_inode+0x242/0x580 fs/jfs/inode.c:102
 jfs_write_inode+0x13f/0x210 fs/jfs/inode.c:132
 write_inode fs/fs-writeback.c:1495 [inline]
 __writeback_single_inode+0x644/0xe30 fs/fs-writeback.c:1705
 writeback_sb_inodes+0xbce/0x1a40 fs/fs-writeback.c:1930
 __writeback_inodes_wb+0x114/0x400 fs/fs-writeback.c:2001
 wb_writeback+0x465/0xc50 fs/fs-writeback.c:2106
 wb_check_background_flush fs/fs-writeback.c:2172 [inline]
 wb_do_writeback fs/fs-writeback.c:2260 [inline]
 wb_workfn+0xd07/0x1130 fs/fs-writeback.c:2288
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8cb1fd20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
4 locks held by kworker/u4:2/154:
 #0: ffff888144594938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc90001fc7d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffff888070a8c0e0 (&type->s_umount_key#43){.+.+}-{3:3}, at: trylock_super+0x1b/0xf0 fs/super.c:418
 #3: ffff88806edaa6c8 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x242/0x580 fs/jfs/inode.c:102
2 locks held by getty/3931:
 #0: ffff88802c31c098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002cd62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
4 locks held by syz-executor383/4169:

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.175-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xe72/0xeb0 kernel/hung_task.c:295
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4169 Comm: syz-executor383 Not tainted 5.15.175-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:172 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0xc/0x60 kernel/kcov.c:206
Code: 89 fb e8 17 00 00 00 48 8b 3d c8 dd 89 0c 48 89 de 5b e9 07 05 49 00 cc cc cc cc cc cc cc 48 8b 04 24 65 48 8b 0d d4 ea 81 7e <65> 8b 15 d5 ea 81 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75
RSP: 0018:ffffc90002d9f018 EFLAGS: 00000246
RAX: ffffffff82ee3f95 RBX: 0000000000000000 RCX: ffff88807ca19dc0
RDX: ffff88807ca19dc0 RSI: 0000000000000000 RDI: 00000000000000ff
RBP: ffffc90002d9f210 R08: ffffffff82ee3f8c R09: ffffed1003e2d224
R10: 0000000000000004 R11: dffffc0000000001 R12: ffff88801f169000
R13: dffffc0000000000 R14: ffff88806edaa930 R15: 0000000000000000
FS:  0000555562fc9380(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055977ef27600 CR3: 000000001f2d8000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 dtSplitRoot+0x8b5/0x1920 fs/jfs/jfs_dtree.c:1976
 dtSplitUp fs/jfs/jfs_dtree.c:990 [inline]
 dtInsert+0x12f6/0x6b00 fs/jfs/jfs_dtree.c:868
 jfs_create+0x7b2/0xbb0 fs/jfs/namei.c:137
 lookup_open fs/namei.c:3462 [inline]
 open_last_lookups fs/namei.c:3532 [inline]
 path_openat+0x130a/0x2f20 fs/namei.c:3739
 do_filp_open+0x21c/0x460 fs/namei.c:3769
 do_sys_openat2+0x13b/0x4f0 fs/open.c:1253
 do_sys_open fs/open.c:1269 [inline]
 __do_sys_openat fs/open.c:1285 [inline]
 __se_sys_openat fs/open.c:1280 [inline]
 __x64_sys_openat+0x243/0x290 fs/open.c:1280
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f6a4b4f4a99
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:00007ffc64226d58 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6a4b4f4a99
RDX: 000000000000275a RSI: 00000000200001c0 RDI: 00000000ffffff9c
RBP: 00007f6a4b56d5f0 R08: 0000555562fca4c0 R09: 0000555562fca4c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc64226d80
R13: 00007ffc64226fa8 R14: 431bde82d7b634db R15: 00007f6a4b53d03b
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.387 msecs