Hello, syzbot found the following issue on: HEAD commit: b6394d6f7159 Merge tag 'pull-misc' of git://git.kernel.org.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=146989a4980000 kernel config: https://syzkaller.appspot.com/x/.config?x=713476114e57eef3 dashboard link: https://syzkaller.appspot.com/bug?extid=08b113332e19a9378dd5 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/e8e1377d4772/disk-b6394d6f.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/19fbbb3b6dd5/vmlinux-b6394d6f.xz kernel image: https://storage.googleapis.com/syzbot-assets/4dcce16af95d/bzImage-b6394d6f.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+08b113332e19a9378dd5@xxxxxxxxxxxxxxxxxxxxxxxxx INFO: task syz-executor.2:9894 blocked for more than 143 seconds. Not tainted 6.9.0-syzkaller-10729-gb6394d6f7159 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.2 state:D stack:24688 pid:9894 tgid:9893 ppid:9055 flags:0x00004006 Call Trace: <TASK> context_switch kernel/sched/core.c:5408 [inline] __schedule+0x1796/0x4a00 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6837 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6894 rwsem_down_write_slowpath+0xeeb/0x13b0 kernel/locking/rwsem.c:1178 __down_write_common+0x1af/0x200 kernel/locking/rwsem.c:1306 inode_lock_nested include/linux/fs.h:826 [inline] do_unlinkat+0x26a/0x830 fs/namei.c:4394 __do_sys_unlink fs/namei.c:4455 [inline] __se_sys_unlink fs/namei.c:4453 [inline] __x64_sys_unlink+0x49/0x60 fs/namei.c:4453 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7faae4e7cee9 RSP: 002b:00007faae5c910c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 00007faae4fabf80 RCX: 00007faae4e7cee9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000a80 RBP: 00007faae4ec949e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007faae4fabf80 R15: 00007ffee8d5b6f8 </TASK> Showing all locks held in the system: 3 locks held by kworker/u8:1/12: 1 lock held by khungtaskd/30: #0: ffffffff8e333d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #0: ffffffff8e333d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #0: ffffffff8e333d20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 2 locks held by kworker/u8:7/2801: 2 locks held by getty/4839: #0: ffff88802f9390a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f162f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201 2 locks held by syz-fuzzer/5091: 3 locks held by kworker/1:6/5155: #0: ffff888015080948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff888015080948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc90003a8fd00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #1: ffffc90003a8fd00 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 #2: ffffffff8e3390f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #2: ffffffff8e3390f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:939 2 locks held by syz-executor.2/9894: #0: ffff888063566420 (sb_writers#35){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:409 #1: ffff88805ef856a8 (&type->i_mutex_dir_key#29/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:826 [inline] #1: ffff88805ef856a8 (&type->i_mutex_dir_key#29/1){+.+.}-{3:3}, at: do_unlinkat+0x26a/0x830 fs/namei.c:4394 2 locks held by syz-executor.2/9897: 3 locks held by syz-executor.4/11013: 2 locks held by syz-executor.4/11026: #0: ffff888021986420 (sb_writers#25){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:409 #1: ffff88805505afe0 (&type->i_mutex_dir_key#20/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:826 [inline] #1: ffff88805505afe0 (&type->i_mutex_dir_key#20/1){+.+.}-{3:3}, at: filename_create+0x260/0x540 fs/namei.c:3900 1 lock held by syz-executor.4/11030: #0: ffff88805505afe0 (&type->i_mutex_dir_key#20){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:801 [inline] #0: ffff88805505afe0 (&type->i_mutex_dir_key#20){++++}-{3:3}, at: lookup_slow+0x45/0x70 fs/namei.c:1708 2 locks held by syz-executor.4/11037: #0: ffff888021986420 (sb_writers#25){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:409 #1: ffff88805505afe0 (&type->i_mutex_dir_key#20/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:826 [inline] #1: ffff88805505afe0 (&type->i_mutex_dir_key#20/1){+.+.}-{3:3}, at: filename_create+0x260/0x540 fs/namei.c:3900 2 locks held by syz-executor.4/11038: #0: ffff888021986420 (sb_writers#25){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:409 #1: ffff88805505afe0 (&type->i_mutex_dir_key#20){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:801 [inline] #1: ffff88805505afe0 (&type->i_mutex_dir_key#20){++++}-{3:3}, at: open_last_lookups fs/namei.c:3573 [inline] #1: ffff88805505afe0 (&type->i_mutex_dir_key#20){++++}-{3:3}, at: path_openat+0x7c4/0x3280 fs/namei.c:3804 4 locks held by kworker/0:2/11663: #0: ffff8880b943e798 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 #1: ffff8880b9428948 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x441/0x770 kernel/sched/psi.c:988 #2: ffff8880b942a718 (&base->lock){-.-.}-{2:2}, at: __debug_check_no_obj_freed lib/debugobjects.c:978 [inline] #2: ffff8880b942a718 (&base->lock){-.-.}-{2:2}, at: debug_check_no_obj_freed+0x234/0x580 lib/debugobjects.c:1019 #3: ffffffff94a429d8 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x16d/0x510 lib/debugobjects.c:708 --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
