INFO: task syz-executor.5:10209 blocked for more than 140 seconds. Not tainted 4.14.295-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D27904 10209 7997 0x00000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 schedule_timeout+0x80a/0xe90 kernel/time/timer.c:1724 do_wait_for_common kernel/sched/completion.c:91 [inline] __wait_for_common kernel/sched/completion.c:112 [inline] wait_for_common+0x272/0x430 kernel/sched/completion.c:123 flush_work+0x3fe/0x770 kernel/workqueue.c:2894 __cancel_work_timer+0x321/0x460 kernel/workqueue.c:2965 p9_conn_destroy net/9p/trans_fd.c:898 [inline] p9_fd_close+0x28d/0x420 net/9p/trans_fd.c:925 p9_client_create+0x736/0x12c0 net/9p/client.c:1093 v9fs_session_init+0x1c5/0x1540 fs/9p/v9fs.c:422 v9fs_mount+0x73/0x860 fs/9p/vfs_super.c:135 mount_fs+0x92/0x2a0 fs/super.c:1237 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2572 [inline] do_mount+0xe65/0x2a30 fs/namespace.c:2905 SYSC_mount fs/namespace.c:3121 [inline] SyS_mount+0xa8/0x120 fs/namespace.c:3098 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7fac15f065f9 RSP: 002b:00007fac14837168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fac16027120 RCX: 00007fac15f065f9 RDX: 0000000020000080 RSI: 0000000020000300 RDI: 0000000000000000 RBP: 00007fac15f617b0 R08: 0000000020000740 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe132df26f R14: 00007fac14837300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/1533: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 3 locks held by kworker/u4:3/2848: #0: ("%s""netns"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2088 #1: (net_cleanup_work){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2092 #2: (net_mutex){+.+.}, at: [] cleanup_net+0x110/0x840 net/core/net_namespace.c:453 2 locks held by kworker/1:2/4315: #0: ("events"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2088 #1: ((&m->rq)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2092 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1533 Comm: khungtaskd Not tainted 4.14.295-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x180 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5b9/0xb40 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5 Comm: kworker/u4:0 Not tainted 4.14.295-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 Workqueue: bat_events batadv_nc_worker task: ffff8880b5fec140 task.stack: ffff8880b5ff8000 RIP: 0010:__lock_acquire+0x5f7/0x3f20 kernel/locking/lockdep.c:3452 RSP: 0018:ffff8880b5fffaa8 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000008 RSI: ffff8880b5feca18 RDI: ffff8880b5fec140 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000020011 R10: ffff8880b5feca18 R11: ffff8880b5fec140 R12: ffff8880b5feca30 R13: 0000000000000011 R14: 0000000000000011 R15: ffffffff8becddc0 FS: 0000000000000000(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f02dac9c2e0 CR3: 00000000b53c8000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 rcu_lock_acquire include/linux/rcupdate.h:242 [inline] rcu_read_lock include/linux/rcupdate.h:629 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:418 [inline] batadv_nc_worker+0x124/0xc50 net/batman-adv/network-coding.c:728 process_one_work+0x793/0x14a0 kernel/workqueue.c:2117 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2251 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: 00 00 41 8b b3 70 08 00 00 ba 07 00 00 00 85 f6 0f 85 65 07 00 00 4c 89 d6 4c 89 df ba 08 00 00 00 4c 89 54 24 28 4c 89 5c 24 20 34 e3 ff ff 4c 8b 5c 24 20 85 c0 4c 8b 54 24 28 0f 84 70 fb