syzbot

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (8932 ticks this GP) idle=1ee/1/0x4000000000000002 softirq=170386/170387 fqs=5246 
rcu: 	 (t=10500 jiffies g=193329 q=280)
NMI backtrace for cpu 0
CPU: 0 PID: 11089 Comm: syz-executor.3 Not tainted 5.1.0-rc7+ #97
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1be/0x236 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x183/0x1cf kernel/rcu/tree.c:1223
 print_cpu_stall kernel/rcu/tree.c:1360 [inline]
 check_cpu_stall kernel/rcu/tree.c:1434 [inline]
 rcu_pending kernel/rcu/tree.c:3103 [inline]
 rcu_sched_clock_irq.cold+0x500/0xa4a kernel/rcu/tree.c:2544
 update_process_times+0x32/0x80 kernel/time/timer.c:1635
 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:161
 tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271
 __run_hrtimer kernel/time/hrtimer.c:1389 [inline]
 __hrtimer_run_queues+0x33e/0xde0 kernel/time/hrtimer.c:1451
 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline]
 smp_apic_timer_interrupt+0x120/0x570 arch/x86/kernel/apic/apic.c:1060
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
 </IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:767 [inline]
RIP: 0010:lock_is_held_type+0x272/0x320 kernel/locking/lockdep.c:4251
Code: ff df c7 83 7c 08 00 00 00 00 00 00 48 c1 e8 03 80 3c 10 00 0f 85 88 00 00 00 48 83 3d 56 b4 3b 07 00 74 31 48 8b 7d c0 57 9d <0f> 1f 44 00 00 48 83 c4 20 44 89 e0 5b 41 5c 41 5d 41 5e 41 5f 5d
RSP: 0018:ffff88808a5ef0f8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff11252ee RBX: ffff888097c302c0 RCX: ffff888097c30b40
RDX: dffffc0000000000 RSI: ffff888094816860 RDI: 0000000000000286
RBP: ffff88808a5ef140 R08: ffff888097c302c0 R09: ffffed1015d05bc8
R10: ffffed1015d05bc7 R11: ffff8880ae82de3b R12: 0000000000000000
R13: ffff888097c30b90 R14: ffff888094816860 R15: 0000000000000003
 lock_is_held include/linux/lockdep.h:351 [inline]
 xa_entry include/linux/xarray.h:1144 [inline]
 xas_descend+0x2a8/0x370 lib/xarray.c:203
 xas_load+0xef/0x150 lib/xarray.c:239
 find_get_entry+0x13d/0x880 mm/filemap.c:1499
 pagecache_get_page+0x4c/0x740 mm/filemap.c:1607
 grab_cache_page_write_begin+0x75/0xb0 mm/filemap.c:3249
 block_write_begin+0x3a/0x1e0 fs/buffer.c:2072
 cont_write_begin+0x4ef/0x8d0 fs/buffer.c:2429
 fat_write_begin+0x8d/0x120 fs/fat/inode.c:229
 generic_perform_write+0x231/0x530 mm/filemap.c:3299
 __generic_file_write_iter+0x25e/0x630 mm/filemap.c:3428
 generic_file_write_iter+0x360/0x610 mm/filemap.c:3460
 call_write_iter include/linux/fs.h:1866 [inline]
 do_iter_readv_writev+0x5e1/0x8e0 fs/read_write.c:681
 do_iter_write fs/read_write.c:957 [inline]
 do_iter_write+0x184/0x610 fs/read_write.c:938
 vfs_iter_write+0x77/0xb0 fs/read_write.c:970
 iter_file_splice_write+0x662/0xbe0 fs/splice.c:745
 do_splice_from fs/splice.c:847 [inline]
 direct_splice_actor+0x126/0x1a0 fs/splice.c:1019
 splice_direct_to_actor+0x369/0x970 fs/splice.c:974
 do_splice_direct+0x1da/0x2a0 fs/splice.c:1062
 do_sendfile+0x597/0xd00 fs/read_write.c:1443
 __do_sys_sendfile64 fs/read_write.c:1498 [inline]
 __se_sys_sendfile64 fs/read_write.c:1490 [inline]
 __x64_sys_sendfile64+0x15a/0x220 fs/read_write.c:1490
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458da9
Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f615a74ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000458da9
RDX: 0000000020000000 RSI: 0000000000000003 RDI: 0000000000000003
RBP: 000000000073c0e0 R08: 0000000000000000 R09: 0000000000000000
R10: 00008080fffffffe R11: 0000000000000246 R12: 00007f615a74f6d4
R13: 00000000004c5fa3 R14: 00000000004da748 R15: 00000000ffffffff