cgroup: fork rejected by pids controller in /syz5
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (1 GPs behind) idle=f92/1/0x4000000000000002 softirq=76667/76668 fqs=4909 
rcu: 	 (t=10500 jiffies g=108569 q=1106)
NMI backtrace for cpu 0
CPU: 0 PID: 29033 Comm: syz-executor0 Not tainted 4.20.0-rc3+ #345
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:164 [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:write_comp_data+0x0/0x70
Code: e8 55 50 43 00 e9 a6 fc ff ff 4c 89 f7 e8 a8 4f 43 00 e9 6f fc ff ff e8 fe 64 c9 ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <55> 48 89 e5 65 4c 8b 04 25 40 ee 01 00 65 8b 05 3c 63 82 7e a9 00
RSP: 0018:ffff888118766b40 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000003 RBX: ffffea00042514f4 RCX: ffffffff81e076fd
RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000005
RBP: ffff888118766b48 R08: fffff9400084a29f R09: fffff9400084a29e
R10: fffff9400084a29e R11: ffffea00042514f7 R12: 0000000000000001
R13: ffffea00042514c0 R14: 1ffff110230ecd85 R15: dffffc0000000000
 put_page_testzero include/linux/mm.h:519 [inline]
 put_page include/linux/mm.h:962 [inline]
 grow_dev_page fs/buffer.c:982 [inline]
 grow_buffers fs/buffer.c:1016 [inline]
 __getblk_slow fs/buffer.c:1043 [inline]
 __getblk_gfp+0x96d/0xd50 fs/buffer.c:1320
 __bread_gfp+0x2d/0x310 fs/buffer.c:1354
 sb_bread include/linux/buffer_head.h:307 [inline]
 fat_ent_bread+0x173/0x290 fs/fat/fatent.c:107
 fat_ent_read_block fs/fat/fatent.c:442 [inline]
 fat_alloc_clusters+0x8db/0x16f0 fs/fat/fatent.c:490
 fat_add_cluster+0x84/0x160 fs/fat/inode.c:101
 __fat_get_block fs/fat/inode.c:148 [inline]
 fat_get_block+0x385/0xb30 fs/fat/inode.c:183
 __block_write_begin_int+0x5ef/0x1d90 fs/buffer.c:1966
 __block_write_begin fs/buffer.c:2016 [inline]
 block_write_begin+0xda/0x370 fs/buffer.c:2075
 cont_write_begin+0x5ba/0x920 fs/buffer.c:2428
 fat_write_begin+0x8d/0x120 fs/fat/inode.c:229
 generic_perform_write+0x3aa/0x6a0 mm/filemap.c:3140
 __generic_file_write_iter+0x26e/0x630 mm/filemap.c:3265
 generic_file_write_iter+0x34d/0x6b0 mm/filemap.c:3293
 call_write_iter include/linux/fs.h:1857 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x6b8/0x9f0 fs/read_write.c:487
 vfs_write+0x1fc/0x560 fs/read_write.c:549
 ksys_write+0x101/0x260 fs/read_write.c:598
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:607
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457569
Code: fd b3 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 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fa0a6c67c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569
RDX: 00000000fffffd97 RSI: 0000000020000180 RDI: 0000000000000008
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa0a6c686d4
R13: 00000000004c5cf1 R14: 00000000004da0a8 R15: 00000000ffffffff
sched: RT throttling activated