INFO: task syz-executor.0:19224 blocked for more than 143 seconds. Not tainted 6.0.0-rc3-syzkaller-00299-gd895ec7938c4 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:28232 pid:19224 ppid: 18399 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5182 [inline] __schedule+0xadf/0x52b0 kernel/sched/core.c:6494 schedule+0xda/0x1b0 kernel/sched/core.c:6570 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6629 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0xa44/0x1350 kernel/locking/mutex.c:747 odev_open+0x5b/0x90 sound/core/seq/oss/seq_oss.c:127 soundcore_open+0x44e/0x620 sound/sound_core.c:593 chrdev_open+0x266/0x770 fs/char_dev.c:414 do_dentry_open+0x4a4/0x13a0 fs/open.c:878 do_open fs/namei.c:3557 [inline] path_openat+0x1c92/0x28f0 fs/namei.c:3691 do_filp_open+0x1b6/0x400 fs/namei.c:3718 do_sys_openat2+0x16d/0x4c0 fs/open.c:1311 do_sys_open fs/open.c:1327 [inline] __do_sys_openat fs/open.c:1343 [inline] __se_sys_openat fs/open.c:1338 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1338 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+0x63/0xcd RIP: 0033:0x7f7b12c89279 RSP: 002b:00007f7b13e55168 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f7b12d9c050 RCX: 00007f7b12c89279 RDX: 0000000000000000 RSI: 0000000020000000 RDI: ffffffffffffff9c RBP: 00007f7b12ce32e9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000006000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7b132cfb1f R14: 00007f7b13e55300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8bf88830 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x26/0xc70 kernel/rcu/tasks.h:507 1 lock held by rcu_tasks_trace/13: #0: ffffffff8bf88530 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x26/0xc70 kernel/rcu/tasks.h:507 1 lock held by khungtaskd/28: #0: ffffffff8bf89380 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6492 2 locks held by syslogd/2956: 2 locks held by getty/3293: #0: ffff8880268a9098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:244 #1: ffffc90002d232f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xef0/0x13e0 drivers/tty/n_tty.c:2177 2 locks held by syz-executor.5/19211: #0: ffffffff8d6c8b68 (register_mutex#4){+.+.}-{3:3}, at: odev_release+0x47/0x70 sound/core/seq/oss/seq_oss.c:143 #1: ffff8880796911f0 (&grp->list_mutex#2){++++}-{3:3}, at: snd_seq_port_disconnect+0x4f/0x5d0 sound/core/seq/seq_ports.c:612 1 lock held by syz-executor.3/19178: #0: ffffffff8d6c8b68 (register_mutex#4){+.+.}-{3:3}, at: odev_release+0x47/0x70 sound/core/seq/oss/seq_oss.c:143 1 lock held by syz-executor.0/19220: #0: ffffffff8d6c8b68 (register_mutex#4){+.+.}-{3:3}, at: odev_open+0x5b/0x90 sound/core/seq/oss/seq_oss.c:127 1 lock held by syz-executor.0/19224: #0: ffffffff8d6c8b68 (register_mutex#4){+.+.}-{3:3}, at: odev_open+0x5b/0x90 sound/core/seq/oss/seq_oss.c:127 1 lock held by syz-executor.2/19275: #0: ffffffff8d6c8b68 (register_mutex#4){+.+.}-{3:3}, at: odev_open+0x5b/0x90 sound/core/seq/oss/seq_oss.c:127 1 lock held by syz-executor.0/19344: #0: ffffffff8d6c8b68 (register_mutex#4){+.+.}-{3:3}, at: odev_open+0x5b/0x90 sound/core/seq/oss/seq_oss.c:127 1 lock held by syz-executor.5/19738: #0: ffffffff8d6c8b68 (register_mutex#4){+.+.}-{3:3}, at: odev_open+0x5b/0x90 sound/core/seq/oss/seq_oss.c:127 1 lock held by syz-executor.0/19814: #0: ffffffff8d6c8b68 (register_mutex#4){+.+.}-{3:3}, at: odev_open+0x5b/0x90 sound/core/seq/oss/seq_oss.c:127 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.0.0-rc3-syzkaller-00299-gd895ec7938c4 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x46/0x14f lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x206/0x250 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xc18/0xf50 kernel/hung_task.c:369 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 41 Comm: kworker/u4:2 Not tainted 6.0.0-rc3-syzkaller-00299-gd895ec7938c4 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 Workqueue: bat_events batadv_nc_worker RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:130 [inline] RIP: 0010:lock_acquire kernel/locking/lockdep.c:5669 [inline] RIP: 0010:lock_acquire+0x1d2/0x570 kernel/locking/lockdep.c:5631 Code: 94 ff ff 48 c7 c7 20 ab ec 89 48 83 c4 20 e8 55 03 20 08 b8 ff ff ff ff 65 0f c1 05 a0 f9 a2 7e 83 f8 01 0f 85 e8 02 00 00 9c <58> f6 c4 02 0f 85 fb 02 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 RSP: 0018:ffffc90000b27b90 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 1ffff92000164f75 RCX: deccaf50687de6aa RDX: 1ffff1100237614e RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff908df947 R10: fffffbfff211bf28 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: ffffffff8bf89380 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000561e5cb45600 CR3: 000000000bc8e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:280 [inline] rcu_read_lock include/linux/rcupdate.h:706 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0x12d/0xfa0 net/batman-adv/network-coding.c:719 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306