syzbot

audit: type=1400 audit(1541570759.634:36): avc:  denied  { map } for  pid=5844 comm="syz-executor394" path="/root/syz-executor394608217" dev="sda1" ino=1426 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
sched: DL replenish lagged too much
hrtimer: interrupt took 4865786 ns
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (14214 ticks this GP) idle=f0a/1/0x4000000000000002 softirq=6436/6438 fqs=5244 
rcu: 	 (t=10500 jiffies g=4517 q=5)
NMI backtrace for cpu 0
CPU: 0 PID: 5844 Comm: syz-executor394 Not tainted 4.20.0-rc1+ #102
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+0x244/0x39d lib/dump_stack.c:113
 nmi_cpu_backtrace.cold.2+0x5c/0xa1 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1e8/0x22a 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:162 [inline]
 rcu_dump_cpu_stacks+0x16f/0x1bc kernel/rcu/tree.c:1195
 print_cpu_stall.cold.67+0x1f3/0x3c7 kernel/rcu/tree.c:1334
 check_cpu_stall kernel/rcu/tree.c:1408 [inline]
 rcu_pending kernel/rcu/tree.c:2961 [inline]
 rcu_check_callbacks+0xf3b/0x13f0 kernel/rcu/tree.c:2506
 update_process_times+0x2d/0x70 kernel/time/timer.c:1636
 tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:164
 tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1274
 __run_hrtimer kernel/time/hrtimer.c:1398 [inline]
 __hrtimer_run_queues+0x41c/0x10d0 kernel/time/hrtimer.c:1460
 hrtimer_interrupt+0x313/0x780 kernel/time/hrtimer.c:1518
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1034 [inline]
 smp_apic_timer_interrupt+0x1a1/0x760 arch/x86/kernel/apic/apic.c:1059
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:804
 </IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:761 [inline]
RIP: 0010:lock_acquire+0x268/0x520 kernel/locking/lockdep.c:3847
Code: 00 00 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 44 02 00 00 48 83 3d 87 21 f0 07 00 0f 84 c3 01 00 00 48 8b bd 20 ff ff ff 57 9d <0f> 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 48 01 c3 48 c7 03 00
RSP: 0018:ffff8801c17e7058 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: dffffc0000000000 RBX: 1ffff100382fce10 RCX: 0000000000000000
RDX: 1ffffffff12a3f76 RSI: 0000000000000000 RDI: 0000000000000286
RBP: ffff8801c17e7148 R08: ffff8801c2232ce0 R09: 0000000000000008
R10: 0000000000004e94 R11: ffff8801c2232440 R12: ffff8801c2232440
R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000000
 down_read+0x8d/0x120 kernel/locking/rwsem.c:24
 pagemap_read+0x8eb/0xb50 fs/proc/task_mmu.c:1510
 do_loop_readv_writev fs/read_write.c:700 [inline]
 do_iter_read+0x4a3/0x650 fs/read_write.c:924
 vfs_readv+0x175/0x1c0 fs/read_write.c:986
 kernel_readv fs/splice.c:362 [inline]
 default_file_splice_read+0x539/0xb20 fs/splice.c:417
 do_splice_to+0x12e/0x190 fs/splice.c:880
 splice_direct_to_actor+0x270/0x8f0 fs/splice.c:952
 do_splice_direct+0x2d4/0x420 fs/splice.c:1061
 do_sendfile+0x62a/0xe20 fs/read_write.c:1439
 __do_sys_sendfile64 fs/read_write.c:1494 [inline]
 __se_sys_sendfile64 fs/read_write.c:1486 [inline]
 __x64_sys_sendfile64+0x15d/0x250 fs/read_write.c:1486
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x440369
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 0f 83 5b 14 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff606ea3f8 EFLAGS: 00000213 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440369
RDX: 0000000020000040 RSI: 0000000000000006 RDI: 0000000000000005
RBP: 00000000006ca018 R08: 0000000000000012 R09: 65732f636f72702f
R10: 0010000000000443 R11: 0000000000000213 R12: 0000000000401c50
R13: 0000000000401ce0 R14: 0000000000000000 R15: 0000000000000000