INFO: task syz-executor.2:15077 blocked for more than 143 seconds. Not tainted 5.17.0-rc2-syzkaller-00167-gdcb85f85fa6f #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.2 state:D stack:27784 pid:15077 ppid: 15054 flags:0x00004004 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 tty_open_by_driver drivers/tty/tty_io.c:2050 [inline] tty_open+0x55e/0x1000 drivers/tty/tty_io.c:2133 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: 0033:0x7f850b4fcf74 RSP: 002b:00007f8509e9dca0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f850b65d030 RCX: 00007f850b4fcf74 RDX: 0000000000000002 RSI: 00007f8509e9dd40 RDI: 00000000ffffff9c RBP: 00007f8509e9dd40 R08: 0000000000000000 R09: 000000000000000e R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 R13: 00007ffc5964999f R14: 00007f8509e9e300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8bb83c20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6460 2 locks held by getty/3273: #0: ffff888023732098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:244 #1: ffffc90002b632e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2077 3 locks held by kworker/u4:14/10109: #0: ffff8880b9d39c58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2b/0x120 kernel/sched/core.c:489 #1: ffffc900046afdb8 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work+0x8c4/0x1650 kernel/workqueue.c:2282 #2: ffff8880b9d28498 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x5a/0x1f0 kernel/time/timer.c:946 1 lock held by syz-executor.2/15077: #0: ffffffff8c5aebe8 (tty_mutex){+.+.}-{3:3}, at: tty_open_by_driver drivers/tty/tty_io.c:2050 [inline] #0: ffffffff8c5aebe8 (tty_mutex){+.+.}-{3:3}, at: tty_open+0x55e/0x1000 drivers/tty/tty_io.c:2133 3 locks held by syz-executor.2/15078: 1 lock held by syz-executor.5/15130: #0: ffffffff8c5aebe8 (tty_mutex){+.+.}-{3:3}, at: tty_open_by_driver drivers/tty/tty_io.c:2050 [inline] #0: ffffffff8c5aebe8 (tty_mutex){+.+.}-{3:3}, at: tty_open+0x55e/0x1000 drivers/tty/tty_io.c:2133 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.17.0-rc2-syzkaller-00167-gdcb85f85fa6f #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: 10109 Comm: kworker/u4:14 Not tainted 5.17.0-rc2-syzkaller-00167-gdcb85f85fa6f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:29 [inline] RIP: 0010:rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:330 [inline] RIP: 0010:rcu_is_watching+0x58/0xb0 kernel/rcu/tree.c:1128 Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 75 51 48 03 1c ed a0 d8 58 8b 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 0f b6 14 02 <48> 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 19 8b 03 83 e0 01 RSP: 0018:ffffc900046afc80 EFLAGS: 00000212 RAX: dffffc0000000000 RBX: ffff8880b9d3ac50 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff8b58d8a8 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff88e5f52d R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000000 R14: dffffc0000000000 R15: 000000000000008a FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2dd33dfe88 CR3: 000000000b88e000 CR4: 0000000000350ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: rcu_read_unlock include/linux/rcupdate.h:723 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline] batadv_nc_worker+0x836/0xfa0 net/batman-adv/network-coding.c:719 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 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: 48 89 fa mov %rdi,%rdx 3: 48 c1 ea 03 shr $0x3,%rdx 7: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) b: 75 51 jne 0x5e d: 48 03 1c ed a0 d8 58 add -0x74a72760(,%rbp,8),%rbx 14: 8b 15: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 1c: fc ff df 1f: 48 89 da mov %rbx,%rdx 22: 48 c1 ea 03 shr $0x3,%rdx 26: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx * 2a: 48 89 d8 mov %rbx,%rax <-- trapping instruction 2d: 83 e0 07 and $0x7,%eax 30: 83 c0 03 add $0x3,%eax 33: 38 d0 cmp %dl,%al 35: 7c 04 jl 0x3b 37: 84 d2 test %dl,%dl 39: 75 19 jne 0x54 3b: 8b 03 mov (%rbx),%eax 3d: 83 e0 01 and $0x1,%eax