INFO: task syz-executor:7803 blocked for more than 143 seconds. Not tainted 6.16.0-rc2-syzkaller-00269-g11313e2f7812 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21776 pid:7803 tgid:7803 ppid:1 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747 lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1444 jfs_umount+0x2ef/0x3c0 fs/jfs/jfs_umount.c:114 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x135/0x2c0 fs/super.c:643 kill_block_super+0x44/0x90 fs/super.c:1755 deactivate_locked_super+0xb9/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1417 task_work_run+0x1d1/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4a2718fc57 RSP: 002b:00007ffd7efce718 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f4a27210925 RCX: 00007f4a2718fc57 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd7efce7d0 RBP: 00007ffd7efce7d0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd7efcf860 R13: 00007f4a27210925 R14: 000000000003aed6 R15: 00007ffd7efcf8a0 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 3 locks held by kworker/1:1/43: 2 locks held by getty/5584: #0: ffff88803534a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 2 locks held by syz-executor/6651: 2 locks held by syz-executor/7803: #0: ffff888055f9a0e0 (&type->s_umount_key#100){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888055f9a0e0 (&type->s_umount_key#100){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888055f9a0e0 (&type->s_umount_key#100){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8e570da8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1444 2 locks held by syz-executor/8346: #0: ffff8880454f80e0 (&type->s_umount_key#100){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880454f80e0 (&type->s_umount_key#100){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880454f80e0 (&type->s_umount_key#100){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8e570da8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1444 2 locks held by kworker/u8:10/8758: 1 lock held by syz.7.307/9279: #0: ffff88804c9160e0 (&type->s_umount_key#100){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88804c9160e0 (&type->s_umount_key#100){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 2 locks held by syz-executor/9480: #0: ffff8880322b60e0 (&type->s_umount_key#100){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880322b60e0 (&type->s_umount_key#100){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880322b60e0 (&type->s_umount_key#100){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8e570da8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1444 1 lock held by syz.2.329/9782: #0: ffff888055f9a0e0 (&type->s_umount_key#100){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] ffff888055f9a0e0 (&type->s_umount_key#100){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 2 locks held by syz-executor/10152: #0: ffff888031f280e0 (&type->s_umount_key#100){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888031f280e0 (&type->s_umount_key#100){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888031f280e0 (&type->s_umount_key#100){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8e570da8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1444 2 locks held by syz-executor/10805: #0: ffff888031c3e0e0 (&type->s_umount_key#100){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888031c3e0e0 (&type->s_umount_key#100){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888031c3e0e0 (&type->s_umount_key#100){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8e570da8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1444 2 locks held by syz.7.642/11542: 1 lock held by syz.3.627/11546: #0: ffffffff8e1448b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #0: ffffffff8e1448b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:998 2 locks held by dhcpcd-run-hook/11547: 1 lock held by udevadm/11576: 1 lock held by dhcpcd/11577: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc2-syzkaller-00269-g11313e2f7812 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6651 Comm: syz-executor Not tainted 6.16.0-rc2-syzkaller-00269-g11313e2f7812 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:serial_lsr_in drivers/tty/serial/8250/8250.h:160 [inline] RIP: 0010:wait_for_lsr+0x1aa/0x2f0 drivers/tty/serial/8250/8250_port.c:2094 Code: 00 74 0a 48 8b 7c 24 18 e8 93 82 e1 fc 48 8b 7c 24 10 4c 8b 5f 50 be 05 00 00 00 41 ff d3 0f 1f 00 48 8b 4c 24 20 0f b6 0c 19 <84> c9 49 89 de 75 4a 0f b7 c0 41 09 c5 48 8b 04 24 0f b7 18 66 44 RSP: 0018:ffffc90004d57178 EFLAGS: 00000002 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020 RBP: ffffffff99d967b0 R08: ffff8880246f8237 R09: 1ffff110048df046 R10: dffffc0000000000 R11: ffffffff854026e0 R12: 1ffffffff33b2cf6 R13: 0000000000000000 R14: dffffc0000000000 R15: 000000000000080a FS: 0000555592274500(0000) GS:ffff888125d83000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd94b664000 CR3: 000000003007a000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3348 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3371 [inline] serial8250_console_write+0x134c/0x1ba0 drivers/tty/serial/8250/8250_port.c:3456 console_emit_next_record kernel/printk/printk.c:3138 [inline] console_flush_all+0x728/0xc40 kernel/printk/printk.c:3226 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0xc4/0x270 kernel/printk/printk.c:3325 vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450 _printk+0xcf/0x120 kernel/printk/printk.c:2475 print_hex_dump+0x180/0x260 lib/hexdump.c:281 jfs_flush_journal+0xc19/0xed0 fs/jfs/jfs_logmgr.c:1598 lmLogShutdown+0xe8/0x830 fs/jfs/jfs_logmgr.c:1643 lmLogClose+0x28a/0x520 fs/jfs/jfs_logmgr.c:1460 jfs_umount+0x2ef/0x3c0 fs/jfs/jfs_umount.c:114 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x135/0x2c0 fs/super.c:643 kill_block_super+0x44/0x90 fs/super.c:1755 deactivate_locked_super+0xb9/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1417 task_work_run+0x1d1/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff15f58fc57 Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffd93a1ce98 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007ff15f610925 RCX: 00007ff15f58fc57 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd93a1cf50 RBP: 00007ffd93a1cf50 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd93a1dfe0 R13: 00007ff15f610925 R14: 0000000000033cf4 R15: 00007ffd93a1e020