syz-executor0(20581): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(20581): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(20581): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(20581): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(20581): getblk(): executed=9 bh_count=0 bh_state=0 rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (1 GPs behind) idle=b3a/1/0x4000000000000002 softirq=43297/43307 fqs=4386 rcu: (t=10500 jiffies g=63049 q=2718) NMI backtrace for cpu 1 CPU: 1 PID: 20581 Comm: syz-executor0 Not tainted 4.20.0-rc6-next-20181214+ #171 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __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:1211 print_cpu_stall.cold.70+0x218/0x40a kernel/rcu/tree.c:1348 check_cpu_stall kernel/rcu/tree.c:1422 [inline] rcu_pending kernel/rcu/tree.c:3018 [inline] rcu_check_callbacks+0xf3b/0x13f0 kernel/rcu/tree.c:2521 update_process_times+0x2d/0x70 kernel/time/timer.c:1635 tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:161 tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1271 __run_hrtimer kernel/time/hrtimer.c:1389 [inline] __hrtimer_run_queues+0x41c/0x10d0 kernel/time/hrtimer.c:1451 hrtimer_interrupt+0x313/0x780 kernel/time/hrtimer.c:1509 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline] smp_apic_timer_interrupt+0x1a1/0x760 arch/x86/kernel/apic/apic.c:1060 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:766 [inline] RIP: 0010:lock_release+0x51d/0xa00 kernel/locking/lockdep.c:3866 Code: 00 00 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 55 03 00 00 48 83 3d 52 30 10 08 00 0f 84 15 02 00 00 48 8b bd e0 fe 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:ffff888192b66ab8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: 1ffff1103256cd5c RCX: 1ffff1103761210e RDX: 1ffffffff12e4816 RSI: 1ffff1103761211a RDI: 0000000000000282 RBP: ffff888192b66be8 R08: 1ffff1103256cd60 R09: ffffed103b5a5b77 R10: 0000000000000003 R11: ffff8881dad2dbbb R12: ffff8881bb090000 R13: 0000000000000002 R14: ffff8881bb090000 R15: ffff888192b66b00 rcu_lock_release include/linux/rcupdate.h:228 [inline] rcu_read_unlock include/linux/rcupdate.h:661 [inline] find_get_entry+0xaae/0x1120 mm/filemap.c:1506 pagecache_get_page+0x12f/0xf00 mm/filemap.c:1579 find_or_create_page include/linux/pagemap.h:322 [inline] grow_dev_page fs/buffer.c:947 [inline] grow_buffers fs/buffer.c:1029 [inline] __getblk_slow fs/buffer.c:1062 [inline] __getblk_gfp+0x4ca/0x1030 fs/buffer.c:1351 __bread_gfp+0x2d/0x310 fs/buffer.c:1385 sb_bread include/linux/buffer_head.h:307 [inline] fat__get_entry+0x5a6/0xa40 fs/fat/dir.c:101 fat_get_entry fs/fat/dir.c:129 [inline] fat_search_long+0x33b/0x1570 fs/fat/dir.c:479 vfat_find+0x16d/0x1a0 fs/fat/namei_vfat.c:697 vfat_lookup+0x107/0x640 fs/fat/namei_vfat.c:711 __lookup_hash+0x12e/0x190 fs/namei.c:1546 filename_create+0x1e5/0x5b0 fs/namei.c:3636 user_path_create fs/namei.c:3693 [inline] do_linkat+0x1d5/0xa90 fs/namei.c:4294 __do_sys_link fs/namei.c:4338 [inline] __se_sys_link fs/namei.c:4336 [inline] __x64_sys_link+0x5e/0x80 fs/namei.c:4336 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457669 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:00007fb47ec50c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000056 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000457669 RDX: 0000000000000000 RSI: 0000000020000340 RDI: 0000000020000240 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb47ec516d4 R13: 00000000004f6b13 R14: 00000000004d4cd0 R15: 00000000ffffffff sched: RT throttling activated syz-executor0(20581): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(20581): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(20581): getblk(): executed=9 bh_count=0 bh_state=0