INFO: task syz-executor256:5124 blocked for more than 143 seconds. Not tainted 6.8.0-rc2-next-20240202-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor256 state:D stack:26392 pid:5124 tgid:5124 ppid:5065 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5400 [inline] __schedule+0x17df/0x4a40 kernel/sched/core.c:6727 __schedule_loop kernel/sched/core.c:6804 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6819 schedule_timeout+0xb0/0x310 kernel/time/timer.c:2159 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x355/0x620 kernel/sched/completion.c:148 __flush_workqueue+0x730/0x1630 kernel/workqueue.c:3617 ceph_mdsc_pre_umount+0x5b5/0x8b0 fs/ceph/mds_client.c:5475 ceph_kill_sb+0x9f/0x4b0 fs/ceph/super.c:1535 deactivate_locked_super+0xc4/0x130 fs/super.c:477 ceph_get_tree+0x9a9/0x17b0 fs/ceph/super.c:1361 vfs_get_tree+0x90/0x2a0 fs/super.c:1784 do_new_mount+0x2be/0xb40 fs/namespace.c:3352 do_mount fs/namespace.c:3692 [inline] __do_sys_mount fs/namespace.c:3898 [inline] __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3875 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7f92db5639f9 RSP: 002b:00007ffcb373c198 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007f92db5639f9 RDX: 0000000020000040 RSI: 00000000200000c0 RDI: 0000000020000080 RBP: 000000000001c290 R08: 0000000000000000 R09: 0000000000000006 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcb373c1ac R13: 431bde82d7b634db R14: 0000000000000001 R15: 0000000000000001 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8e130d60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #0: ffffffff8e130d60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #0: ffffffff8e130d60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 2 locks held by getty/4817: #0: ffff88802ac630a0 (&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+0x6b5/0x1e10 drivers/tty/n_tty.c:2201 1 lock held by syz-executor256/5124: #0: ffff88802299a0e0 (&type->s_umount_key#41/1){+.+.}-{3:3}, at: alloc_super+0x20e/0x8f0 fs/super.c:345 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.8.0-rc2-next-20240202-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106 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:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xfb0/0xff0 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:242 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4510 Comm: klogd Not tainted 6.8.0-rc2-next-20240202-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 RIP: 0010:select_task_rq_fair+0x5/0x3b30 kernel/sched/fair.c:8140 Code: 03 38 c1 7c cc 48 89 df e8 c8 78 8d 00 eb c2 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 <48> 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec 20 01 00 RSP: 0018:ffffc9000318f870 EFLAGS: 00000046 RAX: 1ffffffff1b5c156 RBX: ffffffff8dae0ab0 RCX: dffffc0000000000 RDX: 0000000000000018 RSI: 0000000000000000 RDI: ffff88807c20bc00 RBP: ffffc9000318f9c0 R08: ffffffff8f85b72f R09: 1ffffffff1f0b6e5 R10: dffffc0000000000 R11: ffffffff81694c30 R12: 1ffff92000631f1c R13: ffff88807c20bc14 R14: 0000000000000018 R15: 0000000000000000 FS: 00007f1cedcca380(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005613b0378f48 CR3: 000000007ba38000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: select_task_rq kernel/sched/core.c:3639 [inline] try_to_wake_up+0x648/0x1470 kernel/sched/core.c:4354 autoremove_wake_function+0x16/0x110 kernel/sched/wait.c:384 __wake_up_common kernel/sched/wait.c:89 [inline] __wake_up_common_lock+0x130/0x1e0 kernel/sched/wait.c:106 sock_def_readable+0x1ea/0x450 net/core/sock.c:3353 unix_dgram_sendmsg+0x148e/0x1f80 net/unix/af_unix.c:2172 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 __sys_sendto+0x3a4/0x4f0 net/socket.c:2191 __do_sys_sendto net/socket.c:2203 [inline] __se_sys_sendto net/socket.c:2199 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2199 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7f1cede2c9b5 Code: 8b 44 24 08 48 83 c4 28 48 98 c3 48 98 c3 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 26 45 31 c9 45 31 c0 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 7a 48 8b 15 44 c4 0c 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffedae82188 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f1cede2c9b5 RDX: 0000000000000053 RSI: 00005640f3c22d70 RDI: 0000000000000003 RBP: 00005640f3c1e910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000013 R13: 00007f1cedfba212 R14: 00007ffedae82288 R15: 0000000000000000 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.213 msecs