INFO: task syz-executor.0:11051 can't die for more than 143 seconds. task:syz-executor.0 state:D stack:27800 pid:11051 ppid: 8505 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4327 [inline] __schedule+0x8cd/0x2150 kernel/sched/core.c:5078 schedule+0xcf/0x270 kernel/sched/core.c:5157 rwsem_down_write_slowpath+0x7e5/0x1200 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:2214 do_new_mount_fc fs/namespace.c:2842 [inline] do_new_mount fs/namespace.c:2901 [inline] path_mount+0x1678/0x1e70 fs/namespace.c:3230 do_mount fs/namespace.c:3243 [inline] __do_sys_mount fs/namespace.c:3451 [inline] __se_sys_mount fs/namespace.c:3428 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3428 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e299 RSP: 002b:00007f264db53c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045e299 RDX: 0000000020002100 RSI: 00000000200042c0 RDI: 0000000000000000 RBP: 000000000119c078 R08: 0000000020002140 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119c034 R13: 00007ffc50fd927f R14: 00007f264db549c0 R15: 000000000119c034 INFO: task syz-executor.0:11051 blocked for more than 143 seconds. Not tainted 5.10.0-next-20201223-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:27800 pid:11051 ppid: 8505 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4327 [inline] __schedule+0x8cd/0x2150 kernel/sched/core.c:5078 schedule+0xcf/0x270 kernel/sched/core.c:5157 rwsem_down_write_slowpath+0x7e5/0x1200 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:2214 do_new_mount_fc fs/namespace.c:2842 [inline] do_new_mount fs/namespace.c:2901 [inline] path_mount+0x1678/0x1e70 fs/namespace.c:3230 do_mount fs/namespace.c:3243 [inline] __do_sys_mount fs/namespace.c:3451 [inline] __se_sys_mount fs/namespace.c:3428 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3428 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e299 RSP: 002b:00007f264db53c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045e299 RDX: 0000000020002100 RSI: 00000000200042c0 RDI: 0000000000000000 RBP: 000000000119c078 R08: 0000000020002140 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119c034 R13: 00007ffc50fd927f R14: 00007f264db549c0 R15: 000000000119c034 INFO: task syz-executor.0:11055 can't die for more than 143 seconds. task:syz-executor.0 state:R running task stack:27088 pid:11055 ppid: 8505 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:4327 [inline] __schedule+0x8cd/0x2150 kernel/sched/core.c:5078 Showing all locks held in the system: 1 lock held by khungtaskd/1663: #0: ffffffff8b363660 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6254 1 lock held by in:imklog/8171: #0: ffff888023cbeff0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:949 1 lock held by syz-executor.0/11051: #0: ffff888077680150 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:773 [inline] #0: ffff888077680150 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lock_mount+0x8a/0x2e0 fs/namespace.c:2214 2 locks held by syz-executor.0/11055: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1663 Comm: khungtaskd Not tainted 5.10.0-next-20201223-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: 151 Comm: kworker/u4:4 Not tainted 5.10.0-next-20201223-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:__lock_release kernel/locking/lockdep.c:5128 [inline] RIP: 0010:lock_release+0x1fe/0x710 kernel/locking/lockdep.c:5457 Code: 00 00 45 85 ed 0f 84 ce 02 00 00 48 8d 4c 24 50 44 89 ea 4c 89 e6 4c 89 ff e8 de fc fe ff 48 85 c0 48 89 c3 0f 84 5f 03 00 00 <48> 8d 78 24 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f RSP: 0018:ffffc900011efb58 EFLAGS: 00000082 RAX: ffff8880117025e0 RBX: ffff8880117025e0 RCX: ffffc900011efba8 RDX: 0000000000000004 RSI: ffffffff8b363660 RDI: ffff8880117025e0 RBP: 1ffff9200023df6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8b363660 R13: 0000000000000003 R14: ffff888011702588 R15: ffff888011701c00 FS: 0000000000000000(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f45ee131000 CR3: 000000002362f000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_release include/linux/rcupdate.h:264 [inline] rcu_read_unlock include/linux/rcupdate.h:702 [inline] batadv_nc_process_nc_paths.part.0+0x267/0x3b0 net/batman-adv/network-coding.c:695 batadv_nc_process_nc_paths net/batman-adv/network-coding.c:675 [inline] batadv_nc_worker+0xaf2/0xe50 net/batman-adv/network-coding.c:724 process_one_work+0x98d/0x15f0 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