hrtimer: interrupt took 97365 ns
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (11429 ticks this GP) idle=11e/1/0x4000000000000002 softirq=10841/10843 fqs=5244 
rcu: 	 (t=10500 jiffies g=5017 q=10)
NMI backtrace for cpu 0
CPU: 0 PID: 7755 Comm: syz-executor800 Not tainted 5.1.0-rc4+ #63
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:map_id_up+0x89/0x320 kernel/user_namespace.c:362
Code: f1 f1 f1 c7 40 04 00 04 f3 f3 65 48 8b 04 25 28 00 00 00 48 89 45 d0 31 c0 e8 33 98 03 00 4c 89 f0 48 c1 e8 03 42 0f b6 04 20 <84> c0 74 08 3c 03 0f 8e 35 02 00 00 4c 8b bd 68 ff ff ff 45 8b 37
RSP: 0018:ffff888084e3ef90 EFLAGS: 00000a02 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: ffff888084e3f008 RCX: ffffffff81f27ea9
RDX: 0000000000000000 RSI: ffffffff816cf6cd RDI: ffffffff88970fc0
RBP: ffff888084e3f030 R08: ffff8880a4164500 R09: ffffed10109c7e07
R10: ffffed10109c7e06 R11: 0000000000000003 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff88970fc0 R15: ffff88809608d8f0
 from_kuid+0x85/0xc0 kernel/user_namespace.c:414
 i_uid_read include/linux/fs.h:1531 [inline]
 ext4_do_update_inode fs/ext4/inode.c:5240 [inline]
 ext4_mark_iloc_dirty+0x420/0x2d80 fs/ext4/inode.c:5866
 ext4_mark_inode_dirty+0x23c/0x940 fs/ext4/inode.c:6045
 ext4_dirty_inode+0x8f/0xc0 fs/ext4/inode.c:6076
 __mark_inode_dirty+0x919/0x1290 fs/fs-writeback.c:2155
 mark_inode_dirty include/linux/fs.h:2128 [inline]
 __generic_write_end+0x1b9/0x240 fs/buffer.c:2118
 generic_write_end+0x6c/0x90 fs/buffer.c:2163
 ext4_da_write_end+0x3c8/0xa50 fs/ext4/inode.c:3197
 generic_perform_write+0x2f0/0x530 mm/filemap.c:3310
 __generic_file_write_iter+0x25e/0x630 mm/filemap.c:3428
 ext4_file_write_iter+0x346/0x11c0 fs/ext4/file.c:266
 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:1504 [inline]
 __se_sys_sendfile64 fs/read_write.c:1490 [inline]
 __x64_sys_sendfile64+0x1dd/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: 0033:0x440339
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 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffc4eddfd68 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440339
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 00008000fffffffe R11: 0000000000000246 R12: 0000000000401bc0
R13: 0000000000401c50 R14: 0000000000000000 R15: 0000000000000000