INFO: task syz-executor.4:12403 can't die for more than 143 seconds. task:syz-executor.4 state:D stack:27808 pid:12403 ppid: 8519 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4327 [inline] __schedule+0x8eb/0x21b0 kernel/sched/core.c:5078 schedule+0xcf/0x270 kernel/sched/core.c:5157 rwsem_down_write_slowpath+0x809/0x1220 kernel/locking/rwsem.c:1106 __down_write_common kernel/locking/rwsem.c:1261 [inline] __down_write_common kernel/locking/rwsem.c:1258 [inline] __down_write kernel/locking/rwsem.c:1270 [inline] down_write+0x132/0x150 kernel/locking/rwsem.c:1407 inode_lock include/linux/fs.h:773 [inline] lock_mount+0x8a/0x2e0 fs/namespace.c:2211 do_new_mount_fc fs/namespace.c:2839 [inline] do_new_mount fs/namespace.c:2898 [inline] path_mount+0x1678/0x1e70 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: 0033:0x45e149 RSP: 002b:00007efcb5f3bc68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045e149 RDX: 0000000020002000 RSI: 00000000200042c0 RDI: 0000000000000000 RBP: 000000000119bfd0 R08: 0000000020002140 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c R13: 00007ffec65f50bf R14: 00007efcb5f3c9c0 R15: 000000000119bf8c INFO: task syz-executor.4:12403 blocked for more than 143 seconds. Not tainted 5.10.0-next-20201217-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:27808 pid:12403 ppid: 8519 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4327 [inline] __schedule+0x8eb/0x21b0 kernel/sched/core.c:5078 schedule+0xcf/0x270 kernel/sched/core.c:5157 rwsem_down_write_slowpath+0x809/0x1220 kernel/locking/rwsem.c:1106 __down_write_common kernel/locking/rwsem.c:1261 [inline] __down_write_common kernel/locking/rwsem.c:1258 [inline] __down_write kernel/locking/rwsem.c:1270 [inline] down_write+0x132/0x150 kernel/locking/rwsem.c:1407 inode_lock include/linux/fs.h:773 [inline] lock_mount+0x8a/0x2e0 fs/namespace.c:2211 do_new_mount_fc fs/namespace.c:2839 [inline] do_new_mount fs/namespace.c:2898 [inline] path_mount+0x1678/0x1e70 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: 0033:0x45e149 RSP: 002b:00007efcb5f3bc68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045e149 RDX: 0000000020002000 RSI: 00000000200042c0 RDI: 0000000000000000 RBP: 000000000119bfd0 R08: 0000000020002140 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c R13: 00007ffec65f50bf R14: 00007efcb5f3c9c0 R15: 000000000119bf8c INFO: task syz-executor.4:12410 can't die for more than 144 seconds. task:syz-executor.4 state:R running task stack:27168 pid:12410 ppid: 8519 flags:0x00004006 Call Trace: Showing all locks held in the system: 1 lock held by khungtaskd/1649: #0: ffffffff8b793ae0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x28c kernel/locking/lockdep.c:6254 1 lock held by in:imklog/8188: #0: ffff888021a194f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:947 2 locks held by kworker/u4:3/9867: #0: ffff8880b9d34c58 (&rq->lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1318 [inline] #0: ffff8880b9d34c58 (&rq->lock){-.-.}-{2:2}, at: __schedule+0x235/0x21b0 kernel/sched/core.c:4995 #1: ffffc9001640fda8 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1630 kernel/workqueue.c:2250 1 lock held by syz-executor.4/12403: #0: ffff88807b430150 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:773 [inline] #0: ffff88807b430150 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lock_mount+0x8a/0x2e0 fs/namespace.c:2211 2 locks held by syz-executor.4/12410: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1649 Comm: khungtaskd Not tainted 5.10.0-next-20201217-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+0x3c/0xef 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+0xe75/0x1020 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 9867 Comm: kworker/u4:3 Not tainted 5.10.0-next-20201217-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:hlock_class kernel/locking/lockdep.c:193 [inline] RIP: 0010:mark_lock+0xb1/0x1720 kernel/locking/lockdep.c:4389 Code: 00 00 41 83 fc 08 48 89 f5 0f 84 ff 00 00 00 41 bd 01 00 00 00 44 89 e1 41 d3 e5 4d 63 ed 48 8d 45 20 48 89 c2 48 89 44 24 08 <48> b8 00 00 00 00 00 fc ff df 48 c1 ea 03 0f b6 04 02 84 c0 74 08 RSP: 0018:ffffc9001640f918 EFLAGS: 00000002 RAX: ffff88806fb0a500 RBX: 1ffff92002c81f29 RCX: 0000000000000004 RDX: ffff88806fb0a500 RSI: ffff88806fb0a4e0 RDI: ffff88806fb0a502 RBP: ffff88806fb0a4e0 R08: 0000000000000000 R09: ffffffff8f51d877 R10: fffffbfff1ea3b0e R11: 0000000000000000 R12: 0000000000000009 R13: 0000000000000200 R14: dffffc0000000000 R15: ffff88806fb0a490 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555bd30c5180 CR3: 0000000029a50000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mark_usage kernel/locking/lockdep.c:4332 [inline] __lock_acquire+0x8bf/0x54b0 kernel/locking/lockdep.c:4786 lock_acquire kernel/locking/lockdep.c:5437 [inline] lock_acquire+0x29d/0x750 kernel/locking/lockdep.c:5402 rcu_lock_acquire include/linux/rcupdate.h:259 [inline] rcu_read_lock include/linux/rcupdate.h:648 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:404 [inline] batadv_nc_worker+0x12d/0xe80 net/batman-adv/network-coding.c:715 process_one_work+0x98d/0x1630 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296