syzbot

INFO: task syz-executor.2:23737 can't die for more than 143 seconds.
task:syz-executor.2  state:R  running task     stack:27888 pid:23737 ppid:  8498 flags:0x00004006
Call Trace:
 context_switch kernel/sched/core.c:4327 [inline]
 __schedule+0x8cd/0x2150 kernel/sched/core.c:5078
 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:5238
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:40
 __raw_spin_unlock include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:183
 spin_unlock include/linux/spinlock.h:394 [inline]
 ilookup5_nowait+0x7e/0xb0 fs/inode.c:1335
 ilookup5 fs/inode.c:1363 [inline]
 iget5_locked+0x41/0x220 fs/inode.c:1144
 fuse_iget+0x271/0x610 fs/fuse/inode.c:342
 fuse_direntplus_link fs/fuse/readdir.c:229 [inline]
 parse_dirplusfile fs/fuse/readdir.c:309 [inline]
 fuse_readdir_uncached+0x11e0/0x1730 fs/fuse/readdir.c:357
 fuse_readdir+0x871/0x1830 fs/fuse/readdir.c:580
 iterate_dir+0x4eb/0x660 fs/readdir.c:65
 __do_sys_getdents fs/readdir.c:283 [inline]
 __se_sys_getdents fs/readdir.c:268 [inline]
 __x64_sys_getdents+0x13a/0x2b0 fs/readdir.c:268
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45e219
RSP: 002b:00007f4e52d93c68 EFLAGS: 00000246 ORIG_RAX: 000000000000004e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045e219
RDX: 000000000000008b RSI: 0000000020000000 RDI: 0000000000000004
RBP: 000000000119c068 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119c034
R13: 00007ffed467076f R14: 00007f4e52d949c0 R15: 000000000119c034
INFO: task syz-executor.2:23738 can't die for more than 143 seconds.
task:syz-executor.2  state:D stack:27488 pid:23738 ppid:  8498 flags:0x00004004
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: 0033:0x45e219
RSP: 002b:00007f4e52d72c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045e219
RDX: 0000000020002100 RSI: 00000000200020c0 RDI: 0000000000000000
RBP: 000000000119c120 R08: 0000000020002140 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119c0dc
R13: 00007ffed467076f R14: 00007f4e52d739c0 R15: 000000000119c0dc
INFO: task syz-executor.2:23738 blocked for more than 144 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.2  state:D stack:27488 pid:23738 ppid:  8498 flags:0x00004004
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: 0033:0x45e219
RSP: 002b:00007f4e52d72c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045e219
RDX: 0000000020002100 RSI: 00000000200020c0 RDI: 0000000000000000
RBP: 000000000119c120 R08: 0000000020002140 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119c0dc
R13: 00007ffed467076f R14: 00007f4e52d739c0 R15: 000000000119c0dc

Showing all locks held in the system:
1 lock held by khungtaskd/1651:
 #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/8172:
 #0: ffff8880151c40f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:949
4 locks held by syz-executor.2/23737:
1 lock held by syz-executor.2/23738:
 #0: ffff8880320e0150 (&type->i_mutex_dir_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:773 [inline]
 #0: ffff8880320e0150 (&type->i_mutex_dir_key#9){++++}-{3:3}, at: lock_mount+0x8a/0x2e0 fs/namespace.c:2214

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 1651 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 8682 Comm: kworker/u4:0 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:check_preemption_disabled+0x2c/0x150 lib/smp_processor_id.c:16
Code: 41 55 49 89 f5 41 54 55 48 89 fd 53 0f 1f 44 00 00 65 44 8b 25 75 e6 14 77 65 8b 1d ce 40 15 77 81 e3 ff ff ff 7f 31 ff 89 de <0f> 1f 44 00 00 85 db 74 11 0f 1f 44 00 00 44 89 e0 5b 5d 41 5c 41
RSP: 0018:ffffc900016ffb48 EFLAGS: 00000246
RAX: 0000000000000001 RBX: 0000000000000002 RCX: ffffffff81589558
RDX: 0000000000000001 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffffffff899e9b80 R08: 0000000000000000 R09: ffffffff8cefa18f
R10: fffffbfff19df431 R11: 0000000000000000 R12: 0000000000000001
R13: ffffffff899e9b40 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3d27974008 CR3: 00000000258f1000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 rcu_lockdep_current_cpu_online kernel/rcu/tree.c:1161 [inline]
 rcu_lockdep_current_cpu_online+0x2d/0x150 kernel/rcu/tree.c:1152
 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_acquire include/trace/events/lock.h:13 [inline]
 lock_acquire+0x5c9/0x740 kernel/locking/lockdep.c:5408
 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/0xe50 net/batman-adv/network-coding.c:715
 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