syz-executor0(16591): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(16599): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(16591): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(16599): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(16591): getblk(): executed=9 bh_count=0 bh_state=0 rcu: INFO: rcu_preempt self-detected stall on CPU syz-executor0(16599): getblk(): executed=9 bh_count=0 bh_state=0 rcu: 0-....: (10499 ticks this GP) idle=10a/1/0x4000000000000002 softirq=34518/34518 fqs=4916 rcu: (t=10500 jiffies g=36921 q=1502) NMI backtrace for cpu 0 CPU: 0 PID: 16591 Comm: syz-executor0 Not tainted 4.20.0-rc1-next-20181109+ #110 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:162 [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: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+0x412/0x10c0 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 RIP: 0010:__preempt_count_dec_and_test arch/x86/include/asm/preempt.h:91 [inline] RIP: 0010:rcu_is_watching+0x1a/0x30 kernel/rcu/tree.c:933 Code: 21 ff ff ff e8 c7 af de ff 0f 1f 80 00 00 00 00 55 48 89 e5 65 ff 05 35 bd 97 7e e8 80 fe ff ff 83 f0 01 65 ff 0d 26 bd 97 7e <74> 02 5d c3 e8 7c 4c 96 ff 5d c3 90 66 2e 0f 1f 84 00 00 00 00 00 RSP: 0018:ffff880179996140 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000001 RBX: ffff880179996350 RCX: 1ffff1002f332c1a RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff8801799960d0 RBP: ffff880179996140 R08: ffffed003b5c5b68 R09: ffffed003b5c5b67 R10: ffffed003b5c5b67 R11: ffff8801dae2db3b R12: 0000000000000000 R13: ffff880171b83c80 R14: ffff880171b83442 R15: ffff880179996220 rcu_read_lock_held+0x87/0xc0 kernel/rcu/update.c:277 xa_entry include/linux/xarray.h:848 [inline] xas_descend+0x413/0x510 lib/xarray.c:198 xas_load+0x145/0x1e0 lib/xarray.c:234 find_get_entry+0x3ca/0x1120 mm/filemap.c:1415 pagecache_get_page+0x12f/0xf00 mm/filemap.c:1518 find_get_page_flags include/linux/pagemap.h:278 [inline] __find_get_block_slow fs/buffer.c:205 [inline] __find_get_block+0x635/0xf10 fs/buffer.c:1325 __getblk_slow fs/buffer.c:1058 [inline] __getblk_gfp+0x3d3/0x1030 fs/buffer.c:1351 __bread_gfp+0x2d/0x310 fs/buffer.c:1385 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:1997 __block_write_begin fs/buffer.c:2047 [inline] block_write_begin+0xda/0x370 fs/buffer.c:2106 cont_write_begin+0x5ba/0x920 fs/buffer.c:2459 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:1867 [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:00007f520bb18c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569 RDX: 0000000000000079 RSI: 0000000020000b00 RDI: 0000000000000008 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f520bb196d4 R13: 00000000004c5893 R14: 00000000004d95a0 R15: 00000000ffffffff sched: RT throttling activated syz-executor0(16591): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(16599): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(16591): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(16599): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(16591): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(16599): getblk(): executed=9 bh_count=0 bh_state=0