rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=42845, q=42) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294991868-4294981366), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.1 R running task 24864 21349 9906 0x00004000 Call Trace: sched_show_task kernel/sched/core.c:5952 [inline] sched_show_task.cold+0x2ee/0x35d kernel/sched/core.c:5927 print_other_cpu_stall kernel/rcu/tree_stall.h:430 [inline] check_cpu_stall kernel/rcu/tree_stall.h:558 [inline] rcu_pending kernel/rcu/tree.c:3208 [inline] rcu_sched_clock_irq.cold+0xbee/0xd22 kernel/rcu/tree.c:2279 update_process_times+0x2d/0x70 kernel/time/timer.c:1727 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:171 tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1314 __run_hrtimer kernel/time/hrtimer.c:1517 [inline] __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1579 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1641 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1119 [inline] smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1144 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:94 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:109 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:135 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:166 [inline] RIP: 0010:check_memory_region_inline mm/kasan/generic.c:182 [inline] RIP: 0010:check_memory_region+0x11a/0x1a0 mm/kasan/generic.c:192 Code: 8d 44 25 00 4d 85 c0 75 31 49 89 d9 49 29 c1 e9 68 ff ff ff 5b b8 01 00 00 00 41 5c 41 5d 5d c3 4d 85 c9 74 ef 4d 01 e1 eb 09 <48> 83 c0 01 4c 39 c8 74 e1 80 38 00 74 f2 eb 8c 4d 39 c2 74 4d e8 RSP: 0018:ffffc9000785f2a8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffffed1015d07083 RBX: ffffed1015d07084 RCX: ffffffff81624c24 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880ae838418 RBP: ffffc9000785f2c0 R08: 1ffff11015d07083 R09: ffffed1015d07084 R10: ffffed1015d07083 R11: ffff8880ae83841b R12: ffffed1015d07083 R13: 0000000000000000 R14: ffff8880aa07a208 R15: 0000000000000001 __kasan_check_read+0x11/0x20 mm/kasan/common.c:95 instrument_atomic_read include/linux/instrumented.h:56 [inline] atomic_read include/asm-generic/atomic-instrumented.h:27 [inline] rcu_dynticks_curr_cpu_in_eqs+0x54/0xb0 kernel/rcu/tree.c:302 rcu_is_watching+0x10/0x30 kernel/rcu/tree.c:912 rcu_read_lock_held_common+0xb4/0x130 kernel/rcu/update.c:104 rcu_read_lock_sched_held+0x5b/0xd0 kernel/rcu/update.c:119 trace_writeback_dirty_inode include/trace/events/writeback.h:142 [inline] __mark_inode_dirty+0x750/0x1390 fs/fs-writeback.c:2260 mark_inode_dirty include/linux/fs.h:2183 [inline] generic_write_end+0x2fe/0x3e0 fs/buffer.c:2236 ext4_da_write_end+0x209/0xb60 fs/ext4/inode.c:3092 generic_perform_write+0x2fe/0x540 mm/filemap.c:3304 ext4_buffered_write_iter+0x1fe/0x460 fs/ext4/file.c:270 ext4_file_write_iter+0x1fe/0x14e0 fs/ext4/file.c:642 call_write_iter include/linux/fs.h:1901 [inline] do_iter_readv_writev+0x5f8/0x8f0 fs/read_write.c:693 do_iter_write fs/read_write.c:998 [inline] do_iter_write+0x184/0x610 fs/read_write.c:979 vfs_iter_write+0x77/0xb0 fs/read_write.c:1039 iter_file_splice_write+0x717/0xc10 fs/splice.c:760 do_splice_from fs/splice.c:863 [inline] direct_splice_actor+0x123/0x190 fs/splice.c:1037 splice_direct_to_actor+0x3b4/0xa30 fs/splice.c:992 do_splice_direct+0x1da/0x2a0 fs/splice.c:1080 do_sendfile+0x597/0xd00 fs/read_write.c:1520 __do_sys_sendfile64 fs/read_write.c:1575 [inline] __se_sys_sendfile64 fs/read_write.c:1567 [inline] __x64_sys_sendfile64+0x15a/0x220 fs/read_write.c:1567 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c6b9 Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f17f2161c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f17f21626d4 RCX: 000000000045c6b9 RDX: 00000000200001c0 RSI: 0000000000000008 RDI: 0000000000000008 RBP: 000000000076c060 R08: 0000000000000000 R09: 0000000000000000 R10: 00008080fffffffe R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000008d0 R14: 00000000004cb5c8 R15: 000000000076c06c rcu: rcu_preempt kthread starved for 10502 jiffies! g42845 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29232 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3380 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4080 schedule+0xdc/0x2b0 kernel/sched/core.c:4154 schedule_timeout+0x36e/0x8c0 kernel/time/timer.c:1896 rcu_gp_fqs_loop kernel/rcu/tree.c:1656 [inline] rcu_gp_kthread+0xa02/0x1b00 kernel/rcu/tree.c:1819 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 sched: RT throttling activated