INFO: task syz-executor.3:5824 blocked for more than 143 seconds. Not tainted 6.7.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.3 state:D stack:24112 pid:5824 tgid:5816 ppid:24794 flags:0x00004006 Call Trace: <TASK> context_switch kernel/sched/core.c:5376 [inline] __schedule+0x1961/0x4ab0 kernel/sched/core.c:6688 __schedule_loop kernel/sched/core.c:6763 [inline] schedule+0x149/0x260 kernel/sched/core.c:6778 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6835 rwsem_down_write_slowpath+0xeea/0x13b0 kernel/locking/rwsem.c:1178 __down_write_common+0x1aa/0x200 kernel/locking/rwsem.c:1306 inode_lock include/linux/fs.h:802 [inline] chown_common+0x3e0/0x850 fs/open.c:773 vfs_fchown fs/open.c:851 [inline] ksys_fchown+0xe5/0x150 fs/open.c:862 __do_sys_fchown fs/open.c:870 [inline] __se_sys_fchown fs/open.c:868 [inline] __x64_sys_fchown+0x7a/0x90 fs/open.c:868 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x45/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7faf8327cd29 RSP: 002b:00007faf83f160c8 EFLAGS: 00000246 ORIG_RAX: 000000000000005d RAX: ffffffffffffffda RBX: 00007faf833ac050 RCX: 00007faf8327cd29 RDX: 0000000000000000 RSI: 00000000706d6174 RDI: 0000000000000009 RBP: 00007faf832c947a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007faf833ac050 R15: 00007ffcf4ae5cf8 </TASK> Showing all locks held in the system: 1 lock held by khungtaskd/28: #0: ffffffff8d92dae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:301 [inline] #0: ffffffff8d92dae0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline] #0: ffffffff8d92dae0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 2 locks held by kworker/1:2/54: #0: ffff888012c72938 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2602 [inline] #0: ffff888012c72938 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2700 #1: ffffc90000bf7d20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2602 [inline] #1: ffffc90000bf7d20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2700 2 locks held by getty/4828: #0: ffff88802638e0a0 (&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+0x6b4/0x1e10 drivers/tty/n_tty.c:2201 4 locks held by syz-executor.4/20273: 3 locks held by syz-executor.3/5820: 2 locks held by syz-executor.3/5824: #0: ffff88801c91c418 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write_file+0x61/0x200 fs/namespace.c:448 #1: ffff888078735400 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: inode_lock include/linux/fs.h:802 [inline] #1: ffff888078735400 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: chown_common+0x3e0/0x850 fs/open.c:773 3 locks held by syz-executor.5/5965: 2 locks held by syz-executor.5/5974: #0: ffff88808a250418 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write_file+0x61/0x200 fs/namespace.c:448 #1: ffff888044238400 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: inode_lock include/linux/fs.h:802 [inline] #1: ffff888044238400 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: chown_common+0x3e0/0x850 fs/open.c:773 4 locks held by syz-executor.1/5987: 2 locks held by syz-executor.1/6014: #0: ffff88807759a418 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write_file+0x61/0x200 fs/namespace.c:448 #1: ffff8880443ed400 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: inode_lock include/linux/fs.h:802 [inline] #1: ffff8880443ed400 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: chown_common+0x3e0/0x850 fs/open.c:773 1 lock held by syz-executor.3/6023: #0: ffffffff8d9334b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:325 [inline] #0: ffffffff8d9334b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x46c/0x890 kernel/rcu/tree_exp.h:996 2 locks held by syz-executor.1/6868: 1 lock held by syz-executor.5/6874: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.7.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x498/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x310 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xfaf/0xff0 kernel/hung_task.c:379 kthread+0x2d3/0x370 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 </TASK> Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 6874 Comm: syz-executor.5 Not tainted 6.7.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 RIP: 0033:0x7f986762883b Code: cd 48 01 c1 49 39 4f 08 72 4c 8d 4d ff 85 ed 74 33 66 0f 1f 44 00 00 48 39 f0 72 1b 4d 8b 07 49 89 c1 49 29 f1 47 0f b6 0c 08 <45> 84 c9 74 08 45 88 0c 00 49 8b 47 10 48 83 c0 01 49 89 47 10 83 RSP: 002b:00007f986838c520 EFLAGS: 00000202 RAX: 00000000009f3eb7 RBX: 00007f986838c5c0 RCX: 00000000000000dc RDX: 0000000000000005 RSI: 0000000000000001 RDI: 00007f986838c660 RBP: 0000000000000102 R08: 00007f985da00000 R09: 0000000000000000 R10: 0000000000000000 R11: 00007f986838c5d0 R12: 0000000000000001 R13: 00007f98676eb780 R14: 0000000000000000 R15: 00007f986838c660 FS: 00007f986838d6c0 GS: 0000000000000000