INFO: task syz-executor.0:21344 can't die for more than 143 seconds. task:syz-executor.0 state:D stack:27632 pid:21344 ppid: 8523 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4325 [inline] __schedule+0x8cd/0x2150 kernel/sched/core.c:5076 schedule+0xcf/0x270 kernel/sched/core.c:5155 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1854 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x163/0x260 kernel/sched/completion.c:138 __flush_work+0x51f/0xac0 kernel/workqueue.c:3049 __cancel_work_timer+0x3b3/0x520 kernel/workqueue.c:3136 p9_conn_destroy net/9p/trans_fd.c:891 [inline] p9_fd_close+0x305/0x520 net/9p/trans_fd.c:921 p9_client_destroy+0xbe/0x360 net/9p/client.c:1088 v9fs_session_init+0xfd2/0x1770 fs/9p/v9fs.c:482 v9fs_mount+0x79/0x9b0 fs/9p/vfs_super.c:126 legacy_get_tree+0x105/0x220 fs/fs_context.c:592 vfs_get_tree+0x89/0x2f0 fs/super.c:1549 do_new_mount fs/namespace.c:2896 [inline] path_mount+0x12ae/0x1e70 fs/namespace.c:3227 do_mount fs/namespace.c:3240 [inline] __do_sys_mount fs/namespace.c:3448 [inline] __se_sys_mount fs/namespace.c:3425 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3425 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45deb9 RSP: 002b:00007f931cb3fc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000021840 RCX: 000000000045deb9 RDX: 0000000020000240 RSI: 0000000020000200 RDI: 0000000000000000 RBP: 000000000118c018 R08: 0000000020000580 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bfd4 R13: 00007fff7e37a10f R14: 00007f931cb409c0 R15: 000000000118bfd4 INFO: task syz-executor.0:21344 blocked for more than 143 seconds. Not tainted 5.10.0-rc5-next-20201127-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:27632 pid:21344 ppid: 8523 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4325 [inline] __schedule+0x8cd/0x2150 kernel/sched/core.c:5076 schedule+0xcf/0x270 kernel/sched/core.c:5155 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1854 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x163/0x260 kernel/sched/completion.c:138 __flush_work+0x51f/0xac0 kernel/workqueue.c:3049 __cancel_work_timer+0x3b3/0x520 kernel/workqueue.c:3136 p9_conn_destroy net/9p/trans_fd.c:891 [inline] p9_fd_close+0x305/0x520 net/9p/trans_fd.c:921 p9_client_destroy+0xbe/0x360 net/9p/client.c:1088 v9fs_session_init+0xfd2/0x1770 fs/9p/v9fs.c:482 v9fs_mount+0x79/0x9b0 fs/9p/vfs_super.c:126 legacy_get_tree+0x105/0x220 fs/fs_context.c:592 vfs_get_tree+0x89/0x2f0 fs/super.c:1549 do_new_mount fs/namespace.c:2896 [inline] path_mount+0x12ae/0x1e70 fs/namespace.c:3227 do_mount fs/namespace.c:3240 [inline] __do_sys_mount fs/namespace.c:3448 [inline] __se_sys_mount fs/namespace.c:3425 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3425 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45deb9 RSP: 002b:00007f931cb3fc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000021840 RCX: 000000000045deb9 RDX: 0000000020000240 RSI: 0000000020000200 RDI: 0000000000000000 RBP: 000000000118c018 R08: 0000000020000580 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bfd4 R13: 00007fff7e37a10f R14: 00007f931cb409c0 R15: 000000000118bfd4 Showing all locks held in the system: 1 lock held by khungtaskd/1653: #0: ffffffff8b33a760 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6254 2 locks held by kworker/0:6/14676: #0: ffff888010062d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010062d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888010062d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888010062d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888010062d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888010062d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x871/0x15f0 kernel/workqueue.c:2243 #1: ffffc900018ffda8 ((work_completion)(&m->wq)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x15f0 kernel/workqueue.c:2247 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1653 Comm: khungtaskd Not tainted 5.10.0-rc5-next-20201127-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline] watchdog+0xd89/0xf30 kernel/hung_task.c:338 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 9908 Comm: kworker/u4:6 Not tainted 5.10.0-rc5-next-20201127-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:rcu_lockdep_current_cpu_online+0xd/0x150 kernel/rcu/tree.c:1159 Code: 10 48 8b 4c 24 08 48 8b 14 24 e9 94 fe ff ff 0f 1f 40 00 66 2e 0f 1f 84 00 00 00 00 00 65 8b 15 59 b4 a4 7e 81 e2 00 00 f0 00 01 00 00 00 75 0a 8b 15 be 13 91 0b 85 d2 75 01 c3 55 53 65 ff RSP: 0018:ffffc9001639fbb0 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff8156b431 RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffff8880b9e35f08 RBP: 1ffff92002c73f7b R08: 0000000000000000 R09: ffffffff8cee4e4f R10: fffffbfff19dc9c9 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000000 R14: dffffc0000000000 R15: 000000000000037e FS: 0000000000000000(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fadee0b6000 CR3: 000000001697a000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_lock_held_common kernel/rcu/update.c:110 [inline] rcu_read_lock_held_common kernel/rcu/update.c:100 [inline] rcu_read_lock_sched_held+0x25/0x70 kernel/rcu/update.c:121 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x5b7/0x710 kernel/locking/lockdep.c:5448 rcu_lock_release include/linux/rcupdate.h:260 [inline] rcu_read_unlock include/linux/rcupdate.h:698 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:411 [inline] batadv_nc_worker+0x7a3/0xe50 net/batman-adv/network-coding.c:718 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2272 worker_thread+0x64c/0x1120 kernel/workqueue.c:2418 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296