INFO: task syz.4.50:6253 blocked for more than 143 seconds. Not tainted 6.16.0-rc5-syzkaller-00053-g8c2e52ebbe88 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.50 state:D stack:25128 pid:6253 tgid:6252 ppid:5846 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5401 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6790 __schedule_loop kernel/sched/core.c:6868 [inline] schedule+0x165/0x360 kernel/sched/core.c:6883 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6940 rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write_nested+0x1b5/0x200 kernel/locking/rwsem.c:1694 inode_lock_nested include/linux/fs.h:914 [inline] filename_create+0x1f9/0x470 fs/namei.c:4148 do_mkdirat+0xa0/0x590 fs/namei.c:4400 __do_sys_mkdirat fs/namei.c:4425 [inline] __se_sys_mkdirat fs/namei.c:4423 [inline] __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4423 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f26b058e929 RSP: 002b:00007f26b143b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f26b07b5fa0 RCX: 00007f26b058e929 RDX: 0000000000000020 RSI: 0000200000002040 RDI: ffffffffffffff9c RBP: 00007f26b0610b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f26b07b5fa0 R15: 00007ffc60ad0e38 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: 1 lock held by khungtaskd/31: #0: ffffffff8e13f160 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13f160 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13f160 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 4 locks held by kworker/u8:7/1113: #0: ffff8881404eb148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff8881404eb148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc90003d0fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90003d0fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffff88802cbb40e0 (&type->s_umount_key#60){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563 #3: ffff888058a44b88 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:102 2 locks held by udevd/5205: 2 locks held by getty/5602: #0: ffff8880343320a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5835: #0: ffffffff8e144c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #0: ffffffff8e144c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998 2 locks held by syz.4.50/6253: #0: ffff88802cbb4428 (sb_writers#20){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557 #1: ffff888058a44f38 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:914 [inline] #1: ffff888058a44f38 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: filename_create+0x1f9/0x470 fs/namei.c:4148 4 locks held by syz.4.50/6254: 2 locks held by syz.4.291/8465: 4 locks held by dhcpcd-run-hook/8513: #0: ffff8880b8739e18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:606 #1: ffff8880b8723f08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987 #2: ffff88806769ef18 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] #2: ffff88806769ef18 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: __pte_offset_map_lock+0x13e/0x210 mm/pgtable-generic.c:402 #3: ffffffff8e13f160 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #3: ffffffff8e13f160 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #3: ffffffff8e13f160 (rcu_read_lock){....}-{1:3}, at: page_table_check_set+0x18d/0x730 mm/page_table_check.c:112 2 locks held by sed/8514: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc5-syzkaller-00053-g8c2e52ebbe88 #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+0x711/0x8a0 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5835 Comm: syz-executor Not tainted 6.16.0-rc5-syzkaller-00053-g8c2e52ebbe88 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:format_decode+0x3b6/0xe30 lib/vsprintf.c:2651 Code: 0f b6 04 10 84 c0 0f 85 8b 06 00 00 66 41 c7 04 24 ff ff 48 89 e8 48 c1 e8 03 0f b6 04 10 84 c0 0f 85 9a 06 00 00 0f b6 5d 00 2e 00 00 00 89 de e8 7e fe 5b f6 83 fb 2e 0f 84 44 03 00 00 e8 RSP: 0018:ffffc900041bf150 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 000000000000006c RCX: ffff88803302da00 RDX: dffffc0000000000 RSI: ffffc900041bf1fc RDI: 00000000000000f6 RBP: ffffffff8b8b8a03 R08: ffff88803302da00 R09: 0000000000000002 R10: 0000000000000025 R11: 0000000000000000 R12: ffffc900041bf1fa R13: 1ffff92000837e3f R14: 0000000000000005 R15: ffffffff8b8b8a03 FS: 00005555737dd500(0000) GS:ffff888125c4f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f790ccab286 CR3: 0000000029b8a000 CR4: 00000000003526f0 Call Trace: vsnprintf+0x102/0xf00 lib/vsprintf.c:2817 sprintf+0xd9/0x120 lib/vsprintf.c:3037 print_time kernel/printk/printk.c:1381 [inline] info_print_prefix+0x155/0x310 kernel/printk/printk.c:1407 record_print_text+0x154/0x430 kernel/printk/printk.c:1456 printk_get_next_message+0x26d/0x7b0 kernel/printk/printk.c:3024 console_emit_next_record kernel/printk/printk.c:3092 [inline] console_flush_all+0x4ca/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 _btrfs_printk+0x562/0x5b0 fs/btrfs/messages.c:248 btrfs_put_super+0x69/0x80 fs/btrfs/super.c:73 generic_shutdown_super+0x135/0x2c0 fs/super.c:643 kill_anon_super+0x3b/0x70 fs/super.c:1282 btrfs_kill_super+0x41/0x50 fs/btrfs/super.c:2095 deactivate_locked_super+0xb9/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1417 task_work_run+0x1d4/0x260 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: 0033:0x7f22ac78fc57 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:00007fffebe2ac28 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f22ac810925 RCX: 00007f22ac78fc57 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffebe2ace0 RBP: 00007fffebe2ace0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fffebe2bd70 R13: 00007f22ac810925 R14: 00000000000414bf R15: 00007fffebe2bdb0