syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P10630/1:b..l P5952/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=50997, q=149 ncpus=2)
task:udevd           state:R  running task     stack:26304 pid:5952  ppid:4470   flags:0x00000002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0xee1/0x59f0 kernel/sched/core.c:6710
 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6879
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
 unwind_next_frame+0x16b4/0x2020 arch/x86/kernel/unwind_orc.c:672
 arch_stack_walk+0x8b/0xf0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x96/0xd0 kernel/stacktrace.c:122
 save_stack+0x160/0x1f0 mm/page_owner.c:128
 __reset_page_owner+0x5a/0x190 mm/page_owner.c:149
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1161 [inline]
 free_unref_page_prepare+0x508/0xb90 mm/page_alloc.c:2348
 free_unref_page_list+0xe6/0xb30 mm/page_alloc.c:2489
 release_pages+0x32a/0x14e0 mm/swap.c:1042
 tlb_batch_pages_flush+0x9a/0x190 mm/mmu_gather.c:97
 tlb_flush_mmu_free mm/mmu_gather.c:292 [inline]
 tlb_flush_mmu mm/mmu_gather.c:299 [inline]
 tlb_finish_mmu+0x14b/0x7e0 mm/mmu_gather.c:391
 exit_mmap+0x2db/0x960 mm/mmap.c:3215
 __mmput+0x12a/0x4d0 kernel/fork.c:1348
 mmput+0x62/0x70 kernel/fork.c:1370
 exit_mm kernel/exit.c:567 [inline]
 do_exit+0x9b4/0x2a20 kernel/exit.c:861
 do_group_exit+0xd4/0x2a0 kernel/exit.c:1024
 __do_sys_exit_group kernel/exit.c:1035 [inline]
 __se_sys_exit_group kernel/exit.c:1033 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1033
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f567f6fca90
RSP: 002b:00007fff6cffa218 EFLAGS: 00000216 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f567f6fca90
RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000007 R09: 87ffbc33cf6266d4
R10: 00000000ffffffff R11: 0000000000000216 R12: 000055ba4357caa0
R13: 00007fff6cffa258 R14: 0000000000000001 R15: 000055ba435452c0
 </TASK>
task:syz-executor.5  state:R  running task     stack:27232 pid:10630 ppid:5060   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0xee1/0x59f0 kernel/sched/core.c:6710
 preempt_schedule_irq+0x52/0x90 kernel/sched/core.c:7022
 irqentry_exit+0x35/0x80 kernel/entry/common.c:433
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
RIP: 0010:kasan_mem_to_shadow include/linux/kasan.h:59 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:127 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:178 [inline]
RIP: 0010:kasan_check_range+0x49/0x190 mm/kasan/generic.c:187
Code: 00 00 48 b8 ff ff ff ff ff 7f ff ff 48 39 f8 0f 83 b3 00 00 00 4c 8d 54 37 ff 48 89 fd 48 b8 00 00 00 00 00 fc ff df 4d 89 d1 <48> c1 ed 03 49 c1 e9 03 48 01 c5 49 01 c1 48 89 e8 49 8d 59 01 48
RSP: 0018:ffffc900054df478 EFLAGS: 00000283
RAX: dffffc0000000000 RBX: 1ffff92000a9be95 RCX: ffffffff81663077
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8eaad6d0
RBP: ffffffff8eaad6d0 R08: 0000000000000000 R09: ffffffff8eaad6d7
R10: ffffffff8eaad6d7 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff8c9a3340 R15: 0000000000000000
 instrument_atomic_read include/linux/instrumented.h:68 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 cpumask_test_cpu include/linux/cpumask.h:504 [inline]
 cpu_online include/linux/cpumask.h:1082 [inline]
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0xb7/0x510 kernel/locking/lockdep.c:5732
 rcu_lock_acquire include/linux/rcupdate.h:303 [inline]
 rcu_read_lock include/linux/rcupdate.h:749 [inline]
 percpu_ref_put_many.constprop.0+0x29/0x100 include/linux/percpu-refcount.h:330
 slab_post_alloc_hook mm/slab.h:770 [inline]
 slab_alloc_node mm/slab.c:3237 [inline]
 kmem_cache_alloc_node+0x1ae/0x540 mm/slab.c:3509
 __alloc_skb+0x287/0x330 net/core/skbuff.c:634
 alloc_skb include/linux/skbuff.h:1289 [inline]
 alloc_skb_with_frags+0x9d/0x700 net/core/skbuff.c:6233
 sock_alloc_send_pskb+0x7c8/0x950 net/core/sock.c:2793
 unix_dgram_sendmsg+0x455/0x1c30 net/unix/af_unix.c:1953
 sock_sendmsg_nosec net/socket.c:725 [inline]
 sock_sendmsg+0xd9/0x180 net/socket.c:748
 ____sys_sendmsg+0x2ac/0x940 net/socket.c:2494
 ___sys_sendmsg+0x135/0x1d0 net/socket.c:2548
 __sys_sendmmsg+0x1a1/0x450 net/socket.c:2634
 __do_sys_sendmmsg net/socket.c:2663 [inline]
 __se_sys_sendmmsg net/socket.c:2660 [inline]
 __x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2660
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fb04fe7cae9
RSP: 002b:00007fb04e9dd0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007fb04ff9c120 RCX: 00007fb04fe7cae9
RDX: 0000000000000318 RSI: 00000000200bd000 RDI: 0000000000000006
RBP: 00007fb04fec847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007fb04ff9c120 R15: 00007ffcf3fd5d08
 </TASK>
rcu: rcu_preempt kthread starved for 9940 jiffies! g50997 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:28496 pid:15    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0xee1/0x59f0 kernel/sched/core.c:6710
 schedule+0xe7/0x1b0 kernel/sched/core.c:6786
 schedule_timeout+0x157/0x2c0 kernel/time/timer.c:2167
 rcu_gp_fqs_loop+0x1ec/0xa50 kernel/rcu/tree.c:1609
 rcu_gp_kthread+0x249/0x380 kernel/rcu/tree.c:1808
 kthread+0x33a/0x430 kernel/kthread.c:389
 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
 </TASK>
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:48 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x1b/0x20 drivers/acpi/processor_idle.c:112