syzbot

================================
WARNING: inconsistent lock state
6.0.0-syzkaller-05118-g833477fce7a1 #0 Not tainted
--------------------------------
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
syz-executor.3/5038 [HC0[0]:SC0[0]:HE1:SE1] takes:
ffff888025472c18 (&clnt->lock){?...}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline]
ffff888025472c18 (&clnt->lock){?...}-{2:2}, at: p9_fd_request+0x85/0x330 net/9p/trans_fd.c:672
{IN-HARDIRQ-W} state was registered at:
  lock_acquire kernel/locking/lockdep.c:5666 [inline]
  lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631
  __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
  _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162
  p9_tag_remove net/9p/client.c:367 [inline]
  p9_req_put net/9p/client.c:375 [inline]
  p9_req_put+0xc6/0x250 net/9p/client.c:372
  req_done+0x1de/0x2e0 net/9p/trans_virtio.c:148
  vring_interrupt drivers/virtio/virtio_ring.c:2462 [inline]
  vring_interrupt+0x29d/0x3d0 drivers/virtio/virtio_ring.c:2437
  __handle_irq_event_percpu+0x227/0x870 kernel/irq/handle.c:158
  handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
  handle_irq_event+0xa7/0x1e0 kernel/irq/handle.c:210
  handle_edge_irq+0x25f/0xd00 kernel/irq/chip.c:819
  generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
  handle_irq arch/x86/kernel/irq.c:231 [inline]
  __common_interrupt+0x9d/0x210 arch/x86/kernel/irq.c:250
  common_interrupt+0xa4/0xc0 arch/x86/kernel/irq.c:240
  asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:640
  rcu_rdp_cpu_online kernel/rcu/tree.c:235 [inline]
  rcu_lockdep_current_cpu_online kernel/rcu/tree.c:774 [inline]
  rcu_lockdep_current_cpu_online+0x89/0x140 kernel/rcu/tree.c:758
  rcu_read_lock_held_common kernel/rcu/update.c:112 [inline]
  rcu_read_lock_held_common kernel/rcu/update.c:102 [inline]
  rcu_read_lock_sched_held+0x25/0x70 kernel/rcu/update.c:123
  trace_lock_release include/trace/events/lock.h:69 [inline]
  lock_release+0x560/0x780 kernel/locking/lockdep.c:5677
  up_read+0x12/0x20 kernel/locking/rwsem.c:1594
  kernfs_dop_revalidate+0x34f/0x600 fs/kernfs/dir.c:1117
  d_revalidate fs/namei.c:856 [inline]
  d_revalidate fs/namei.c:853 [inline]
  lookup_fast+0x22d/0x520 fs/namei.c:1646
  walk_component+0x5e/0x5a0 fs/namei.c:1989
  link_path_walk.part.0+0x74e/0xe20 fs/namei.c:2320
  link_path_walk fs/namei.c:2244 [inline]
  path_lookupat+0xb7/0x840 fs/namei.c:2473
  filename_lookup+0x1ce/0x590 fs/namei.c:2503
  vfs_statx+0x14c/0x430 fs/stat.c:229
  vfs_fstatat+0x8c/0xb0 fs/stat.c:267
  __do_sys_newfstatat+0x94/0x120 fs/stat.c:437
  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
  do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
  entry_SYSCALL_64_after_hwframe+0x63/0xcd
irq event stamp: 407
hardirqs last  enabled at (407): [<ffffffff89a00cc6>] asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
hardirqs last disabled at (406): [<ffffffff8983cdfb>] sysvec_apic_timer_interrupt+0xb/0xc0 arch/x86/kernel/apic/apic.c:1107
softirqs last  enabled at (254): [<ffffffff81473f03>] invoke_softirq kernel/softirq.c:445 [inline]
softirqs last  enabled at (254): [<ffffffff81473f03>] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650
softirqs last disabled at (245): [<ffffffff81473f03>] invoke_softirq kernel/softirq.c:445 [inline]
softirqs last disabled at (245): [<ffffffff81473f03>] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&clnt->lock);
  <Interrupt>
    lock(&clnt->lock);

 *** DEADLOCK ***

no locks held by syz-executor.3/5038.

stack backtrace:
CPU: 2 PID: 5038 Comm: syz-executor.3 Not tainted 6.0.0-syzkaller-05118-g833477fce7a1 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_usage_bug kernel/locking/lockdep.c:3961 [inline]
 valid_state kernel/locking/lockdep.c:3973 [inline]
 mark_lock_irq kernel/locking/lockdep.c:4176 [inline]
 mark_lock.part.0.cold+0x18/0xd8 kernel/locking/lockdep.c:4632
 mark_lock kernel/locking/lockdep.c:4596 [inline]
 mark_usage kernel/locking/lockdep.c:4541 [inline]
 __lock_acquire+0x847/0x56d0 kernel/locking/lockdep.c:5007
 lock_acquire kernel/locking/lockdep.c:5666 [inline]
 lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:349 [inline]
 p9_fd_request+0x85/0x330 net/9p/trans_fd.c:672
 p9_client_rpc+0x2f0/0xce0 net/9p/client.c:660
 p9_client_version net/9p/client.c:880 [inline]
 p9_client_create+0xaec/0x1070 net/9p/client.c:985
 v9fs_session_init+0x1e2/0x1810 fs/9p/v9fs.c:408
 v9fs_mount+0xba/0xc90 fs/9p/vfs_super.c:126
 legacy_get_tree+0x105/0x220 fs/fs_context.c:610
 vfs_get_tree+0x89/0x2f0 fs/super.c:1530
 do_new_mount fs/namespace.c:3040 [inline]
 path_mount+0x1326/0x1e20 fs/namespace.c:3370
 do_mount fs/namespace.c:3383 [inline]
 __do_sys_mount fs/namespace.c:3591 [inline]
 __se_sys_mount fs/namespace.c:3568 [inline]
 __x64_sys_mount+0x27f/0x300 fs/namespace.c:3568
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f886328a5a9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f88643be168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f88633abf80 RCX: 00007f886328a5a9
RDX: 00000000200001c0 RSI: 0000000020000040 RDI: 0000000000000000
RBP: 00007f88632e5580 R08: 0000000020000400 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff6bdfda6f R14: 00007f88643be300 R15: 0000000000022000
 </TASK>