INFO: task kworker/u8:1:12 blocked for more than 143 seconds. Not tainted 6.12.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:1 state:D stack:22104 pid:12 tgid:12 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1843/0x4ae0 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6824 __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 Showing all locks held in the system: 4 locks held by kworker/u8:1/12: #0: ffff8880202eb148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff8880202eb148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90000117d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000117d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffff88807b4d80e0 (&type->s_umount_key#44){.+.+}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562 #3: ffff8880720e2fe0 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x24a/0x590 fs/jfs/inode.c:102 1 lock held by khungtaskd/30: #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720 2 locks held by getty/4977: #0: ffff88802f38e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 4 locks held by syz-executor587/5251: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __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 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5251 Comm: syz-executor587 Not tainted 6.12.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x18/0x70 kernel/kcov.c:217 Code: 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 80 d7 03 00 65 8b 15 50 f1 6e 7e <81> e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00 RSP: 0018:ffffc90004087498 EFLAGS: 00000246 RAX: ffffffff832ad09e RBX: ffff88807662a000 RCX: ffff88807f558000 RDX: 0000000080000000 RSI: 0000000000000000 RDI: 00000000000000ff RBP: ffffc90004087690 R08: ffffffff832ad070 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1100ecc5400 R13: dffffc0000000000 R14: ffff8880720e3248 R15: 0000000000000000 FS: 0000555559ad6380(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005650d3f277f0 CR3: 000000007d3aa000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: dtSplitRoot+0x8de/0x1930 fs/jfs/jfs_dtree.c:1980 dtSplitUp fs/jfs/jfs_dtree.c:992 [inline] dtInsert+0x12cd/0x6c10 fs/jfs/jfs_dtree.c:870 jfs_mkdir+0x7fb/0xba0 fs/jfs/namei.c:270 vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4257 do_mkdirat+0x264/0x3a0 fs/namei.c:4280 __do_sys_mkdir fs/namei.c:4300 [inline] __se_sys_mkdir fs/namei.c:4298 [inline] __x64_sys_mkdir+0x6c/0x80 fs/namei.c:4298 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: 0033:0x7f7f80705ad7 Code: ff ff 77 07 31 c0 c3 0f 1f 40 00 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 b8 53 00 00 00 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:00007ffd57a1f448 EFLAGS: 00000246 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 0000000020000e80 RCX: 00007f7f80705ad7 RDX: 0000000000000000 RSI: 00000000000001ff RDI: 0000000020000e80 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd57a1f4e0 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.293 msecs