rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P15827/1:b..l
(detected by 1, t=10502 jiffies, g=73849, q=248)
task:syz.6.3735 state:R running task stack:22576 pid:15827 ppid: 13011 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
irqentry_exit+0x63/0x70 kernel/entry/common.c:432
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x60 kernel/kcov.c:205
Code: 84 00 00 00 00 00 53 48 89 fb e8 17 00 00 00 48 8b 3d 90 bc 10 0c 48 89 de 5b e9 17 42 44 00 00 00 cc cc 00 00 cc 48 8b 04 24 <65> 48 8b 0d e4 4e 89 7e 65 8b 15 e5 4e 89 7e 81 e2 00 01 ff 00 74
RSP: 0018:ffffc90002fbecd8 EFLAGS: 00000293
RAX: ffffffff81506bf5 RBX: 00fff00000080003 RCX: ffff8880295dd940
RDX: 0000000000000000 RSI: ffffffff8a79f720 RDI: ffffffff8a79f6e0
RBP: 0000000000000001 R08: dffffc0000000000 R09: 1ffffffff203a418
R10: dffffc0000000000 R11: fffffbfff203a419 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffea000256e4c0 R15: dffffc0000000000
kthread_blkcg+0x15/0xd0 kernel/kthread.c:1485
blk_cgroup_congested include/linux/blk-cgroup.h:281 [inline]
__cgroup_throttle_swaprate+0xf4/0x530 mm/swapfile.c:3809
cgroup_throttle_swaprate include/linux/swap.h:728 [inline]
shmem_add_to_page_cache+0xb90/0x14d0 mm/shmem.c:727
shmem_getpage_gfp+0x1796/0x2d40 mm/shmem.c:1940
shmem_getpage mm/shmem.c:151 [inline]
shmem_write_begin+0xcd/0x1a0 mm/shmem.c:2474
generic_perform_write+0x2b6/0x550 mm/filemap.c:3785
__generic_file_write_iter+0x25f/0x4e0 mm/filemap.c:3912
generic_file_write_iter+0xa6/0x1b0 mm/filemap.c:3944
__kernel_write+0x51c/0x970 fs/read_write.c:539
__dump_emit+0x249/0x370 fs/coredump.c:943
dump_user_range+0x84/0x340 fs/coredump.c:1017
elf_core_dump+0x2fbd/0x3500 fs/binfmt_elf.c:2285
do_coredump+0x14c7/0x2ac0 fs/coredump.c:894
get_signal+0x40a/0x12c0 kernel/signal.c:2886
arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:320
exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1499
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0033:0x7fad80c90ec1
RSP: 002b:0000000000000030 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fad80f0c090 RCX: 00007fad80c90eb9
RDX: 0000000000000000 RSI: 0000000000000030 RDI: 0000000000000600
RBP: 00007fad80cfec1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fad80f0c128 R14: 00007fad80f0c090 R15: 00007ffda4570ed8
rcu: rcu_preempt kthread starved for 9638 jiffies! g73849 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt state:R running task stack:27632 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x184/0x2d0 kernel/time/timer.c:1914
rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 0 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:729