INFO: task syz-executor.1:9239 blocked for more than 143 seconds. Not tainted 5.17.0-rc2-syzkaller-00071-g1f2cfdd349b7 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.1 state:D stack:28616 pid: 9239 ppid: 8701 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4986 [inline] __schedule+0xab2/0x4db0 kernel/sched/core.c:6295 schedule+0xd2/0x260 kernel/sched/core.c:6368 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6427 __mutex_lock_common kernel/locking/mutex.c:673 [inline] __mutex_lock+0xa32/0x12f0 kernel/locking/mutex.c:733 ptmx_open drivers/tty/pty.c:833 [inline] ptmx_open+0x103/0x360 drivers/tty/pty.c:800 chrdev_open+0x266/0x770 fs/char_dev.c:414 do_dentry_open+0x4b9/0x1240 fs/open.c:824 do_open fs/namei.c:3476 [inline] path_openat+0x1c9e/0x2940 fs/namei.c:3609 do_filp_open+0x1aa/0x400 fs/namei.c:3636 do_sys_openat2+0x16d/0x4d0 fs/open.c:1214 do_sys_open fs/open.c:1230 [inline] __do_sys_openat fs/open.c:1246 [inline] __se_sys_openat fs/open.c:1241 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1241 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fb8f91b8059 RSP: 002b:00007fb8f7b2d168 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fb8f92caf60 RCX: 00007fb8f91b8059 RDX: 0000000000000000 RSI: 00000000200000c0 RDI: ffffffffffffff9c RBP: 00007fb8f921208d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffdceed786f R14: 00007fb8f7b2d300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8bb81120 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6460 2 locks held by getty/3274: #0: ffff88807ec65098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:244 #1: ffffc90002b5b2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2077 2 locks held by kworker/u4:1/8929: #0: ffff8880b9d39cd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2b/0x120 kernel/sched/core.c:489 #1: ffff8880b9d27948 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: process_one_work+0x8c4/0x1650 kernel/workqueue.c:2282 3 locks held by syz-executor.0/9241: 1 lock held by syz-executor.1/9239: #0: ffffffff8c5acb88 (tty_mutex){+.+.}-{3:3}, at: ptmx_open drivers/tty/pty.c:833 [inline] #0: ffffffff8c5acb88 (tty_mutex){+.+.}-{3:3}, at: ptmx_open+0x103/0x360 drivers/tty/pty.c:800 1 lock held by syz-executor.3/9284: #0: ffffffff8c5acb88 (tty_mutex){+.+.}-{3:3}, at: ptmx_open drivers/tty/pty.c:833 [inline] #0: ffffffff8c5acb88 (tty_mutex){+.+.}-{3:3}, at: ptmx_open+0x103/0x360 drivers/tty/pty.c:800 1 lock held by syz-executor.2/9327: #0: ffffffff8c5acb88 (tty_mutex){+.+.}-{3:3}, at: ptmx_open drivers/tty/pty.c:833 [inline] #0: ffffffff8c5acb88 (tty_mutex){+.+.}-{3:3}, at: ptmx_open+0x103/0x360 drivers/tty/pty.c:800 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.17.0-rc2-syzkaller-00071-g1f2cfdd349b7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xc1d/0xf50 kernel/hung_task.c:369 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8929 Comm: kworker/u4:1 Not tainted 5.17.0-rc2-syzkaller-00071-g1f2cfdd349b7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:prandom_u32+0x1ed/0x470 lib/random32.c:391 Code: 46 9c fd 84 db 0f 85 2b 01 00 00 e8 ed 42 9c fd bf 01 00 00 00 e8 93 41 74 fd 31 ff 65 8b 1d 5a 04 27 7c 89 de e8 f3 44 9c fd <85> db 0f 84 d4 01 00 00 e8 c6 42 9c fd 44 89 e0 48 83 c4 08 5b 5d RSP: 0018:ffffc90003687ae8 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000002 RDX: 0000000000000000 RSI: ffff88807e1740c0 RDI: 0000000000000003 RBP: ffff8880b9d36a20 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff83db6b6d R11: 0000000000000000 R12: 0000000041e6e83b R13: ffff88807e174b20 R14: ffff88807e174b20 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fea14e4a680 CR3: 000000001fa4b000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_pin_lock kernel/locking/lockdep.c:5409 [inline] lock_pin_lock+0x1a3/0x2c0 kernel/locking/lockdep.c:5703 rq_pin_lock kernel/sched/sched.h:1539 [inline] rq_lock kernel/sched/sched.h:1617 [inline] __schedule+0x291/0x4db0 kernel/sched/core.c:6209 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6461 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irq+0x3c/0x40 kernel/locking/spinlock.c:202 process_one_work+0x8a2/0x1650 kernel/workqueue.c:2280 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: 46 9c rex.RX pushfq 2: fd std 3: 84 db test %bl,%bl 5: 0f 85 2b 01 00 00 jne 0x136 b: e8 ed 42 9c fd callq 0xfd9c42fd 10: bf 01 00 00 00 mov $0x1,%edi 15: e8 93 41 74 fd callq 0xfd7441ad 1a: 31 ff xor %edi,%edi 1c: 65 8b 1d 5a 04 27 7c mov %gs:0x7c27045a(%rip),%ebx # 0x7c27047d 23: 89 de mov %ebx,%esi 25: e8 f3 44 9c fd callq 0xfd9c451d * 2a: 85 db test %ebx,%ebx <-- trapping instruction 2c: 0f 84 d4 01 00 00 je 0x206 32: e8 c6 42 9c fd callq 0xfd9c42fd 37: 44 89 e0 mov %r12d,%eax 3a: 48 83 c4 08 add $0x8,%rsp 3e: 5b pop %rbx 3f: 5d pop %rbp