syzbot

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (10499 ticks this GP) idle=597/1/0x4000000000000000 softirq=81029/81029 fqs=41 
	(t=10500 jiffies g=101993 q=293 ncpus=2)
rcu: rcu_preempt kthread starved for 10416 jiffies! g101993 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
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:29096 pid:   16 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5106 [inline]
 __schedule+0xa9a/0x4cc0 kernel/sched/core.c:6421
 schedule+0xd2/0x1f0 kernel/sched/core.c:6493
 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1907
 rcu_gp_fqs_loop+0x1c0/0x840 kernel/rcu/tree.c:2078
 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2267
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3038 Comm: syz-executor.3 Not tainted 5.18.0-rc3-next-20220422-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:kvm_wait+0x98/0x100 arch/x86/kernel/kvm.c:1058
Code: fa 83 e2 07 38 d0 7f 04 84 c0 75 63 0f b6 07 40 38 c6 74 35 48 83 c4 10 c3 c3 e8 23 91 4b 00 eb 07 0f 00 2d da b1 94 08 fb f4 <48> 83 c4 10 c3 89 74 24 0c 48 89 3c 24 e8 56 8f 4b 00 8b 74 24 0c
RSP: 0018:ffffc900146ff978 EFLAGS: 00000246
RAX: 0000000000000007 RBX: ffff8880b9c3ae40 RCX: 1ffffffff1b73199
RDX: 0000000000000000 RSI: ffffffff81807171 RDI: ffffffff8134dffd
RBP: ffff8880b9d3ae54 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff81807158 R11: 0000000000000000 R12: ffffed10173875ca
R13: ffff8880b9c3ae54 R14: dffffc0000000000 R15: ffff8880b9d3ae40
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2ce45000 CR3: 0000000019a1a000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 pv_wait arch/x86/include/asm/paravirt.h:603 [inline]
 pv_wait_node kernel/locking/qspinlock_paravirt.h:325 [inline]
 __pv_queued_spin_lock_slowpath+0x6d8/0xb50 kernel/locking/qspinlock.c:476
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
 do_raw_spin_lock+0x200/0x2a0 kernel/locking/spinlock_debug.c:115
 spin_lock include/linux/spinlock.h:354 [inline]
 task_lock include/linux/sched/task.h:170 [inline]
 mm_update_next_owner+0x21a/0x7a0 kernel/exit.c:457
 exit_mm kernel/exit.c:509 [inline]
 do_exit+0xa0a/0x2a00 kernel/exit.c:782
 do_group_exit+0xd2/0x2f0 kernel/exit.c:925
 get_signal+0x22df/0x24c0 kernel/signal.c:2864
 arch_do_signal_or_restart+0x82/0x20f0 arch/x86/kernel/signal.c:869
 exit_to_user_mode_loop kernel/entry/common.c:166 [inline]
 exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:294
 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fa74a43bd2b
Code: Unable to access opcode bytes at RIP 0x7fa74a43bd01.
RSP: 002b:00007ffe1752d230 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00007fa74a43bd2b
RDX: 0000001b2ce20000 RSI: 00007fa74a009d50 RDI: 0000000000000003
RBP: 00007fa74a59d960 R08: 0000000000000000 R09: 00000000a32f770e
R10: 00007ffe1754c090 R11: 0000000000000293 R12: 00000000000e70c7
R13: 00007ffe1752d330 R14: 00007fa74a59c100 R15: 0000000000000032
 </TASK>
NMI backtrace for cpu 0
CPU: 0 PID: 3040 Comm: syz-executor.3 Not tainted 5.18.0-rc3-next-20220422-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1e6/0x230 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x262/0x3f0 kernel/rcu/tree_stall.h:369
 print_cpu_stall kernel/rcu/tree_stall.h:665 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:749 [inline]
 rcu_pending kernel/rcu/tree.c:4068 [inline]
 rcu_sched_clock_irq.cold+0x144/0x8fc kernel/rcu/tree.c:2755
 update_process_times+0x16d/0x200 kernel/time/timer.c:1811
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:243
 tick_sched_timer+0xee/0x120 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1112
 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1106
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:kvm_wait+0x98/0x100 arch/x86/kernel/kvm.c:1058
Code: fa 83 e2 07 38 d0 7f 04 84 c0 75 63 0f b6 07 40 38 c6 74 35 48 83 c4 10 c3 c3 e8 23 91 4b 00 eb 07 0f 00 2d da b1 94 08 fb f4 <48> 83 c4 10 c3 89 74 24 0c 48 89 3c 24 e8 56 8f 4b 00 8b 74 24 0c
RSP: 0018:ffffc900000076e8 EFLAGS: 00000246
RAX: 0000000000000007 RBX: 0000000000000000 RCX: 1ffffffff1b73199
RDX: 0000000000000000 RSI: ffffffff81807171 RDI: ffffffff8134dffd
RBP: ffff888077fd61c8 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff81807158 R11: 0000000000000001 R12: 0000000000000000
R13: ffffed100effac39 R14: 0000000000000001 R15: ffff8880b9c3ae40
 pv_wait arch/x86/include/asm/paravirt.h:603 [inline]
 pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
 __pv_queued_spin_lock_slowpath+0x8c7/0xb50 kernel/locking/qspinlock.c:511
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
 do_raw_spin_lock+0x200/0x2a0 kernel/locking/spinlock_debug.c:115
 spin_lock include/linux/spinlock.h:354 [inline]
 task_lock include/linux/sched/task.h:170 [inline]
 __get_task_comm+0x23/0x50 fs/exec.c:1219
 __set_page_owner_handle mm/page_owner.c:174 [inline]
 __set_page_owner+0x253/0x380 mm/page_owner.c:192
 prep_new_page mm/page_alloc.c:2394 [inline]
 get_page_from_freelist+0xba2/0x3e00 mm/page_alloc.c:4135
 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5356
 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2273
 skb_page_frag_refill net/core/sock.c:2751 [inline]
 skb_page_frag_refill+0x191/0x360 net/core/sock.c:2735
 add_recvbuf_mergeable drivers/net/virtio_net.c:1357 [inline]
 try_fill_recv+0x747/0x1960 drivers/net/virtio_net.c:1398
 virtnet_receive drivers/net/virtio_net.c:1512 [inline]
 virtnet_poll+0x95a/0x11a0 drivers/net/virtio_net.c:1609
 __napi_poll+0xb3/0x6e0 net/core/dev.c:6443
 napi_poll net/core/dev.c:6510 [inline]
 net_rx_action+0x8ec/0xc60 net/core/dev.c:6597
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649
 common_interrupt+0xa9/0xc0 arch/x86/kernel/irq.c:240
 </IRQ>
 <TASK>
 asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:640
RIP: 0010:check_region_inline mm/kasan/generic.c:169 [inline]
RIP: 0010:kasan_check_range+0x9/0x180 mm/kasan/generic.c:189
Code: b6 f5 bf 00 08 00 00 89 43 0c e8 72 e4 ff ff 89 43 08 5b 5d 41 5c c3 66 2e 0f 1f 84 00 00 00 00 00 48 85 f6 0f 84 3c 01 00 00 <49> 89 f9 41 54 44 0f b6 c2 49 01 f1 55 53 0f 82 18 01 00 00 48 b8
RSP: 0018:ffffc90014767430 EFLAGS: 00000202
RAX: 000000000002be17 RBX: ffff888077fd60b0 RCX: ffffffff841f6e0e
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff888077fd60b0
RBP: 8080808080808080 R08: 0000000000000001 R09: 0000000000000003
R10: fffff520028ece89 R11: 0000000000000001 R12: 0000000000000010
R13: 0000000000000000 R14: fefefefefefefeff R15: ffff8880133b2a68
 read_word_at_a_time+0xe/0x20 include/asm-generic/rwonce.h:85
 strscpy+0xa1/0x2a0 lib/string.c:203
 strscpy include/linux/fortify-string.h:170 [inline]
 strscpy_pad+0x20/0x70 lib/string_helpers.c:788
 __get_task_comm+0x35/0x50 fs/exec.c:1221
 __set_page_owner_handle mm/page_owner.c:174 [inline]
 __set_page_owner+0x253/0x380 mm/page_owner.c:192
 prep_new_page mm/page_alloc.c:2394 [inline]
 get_page_from_freelist+0xba2/0x3e00 mm/page_alloc.c:4135
 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5356
 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2273
 folio_alloc+0x1c/0x70 mm/mempolicy.c:2283
 filemap_alloc_folio mm/filemap.c:996 [inline]
 __filemap_get_folio+0x614/0xf00 mm/filemap.c:1992
 pagecache_get_page+0x2e/0x290 mm/folio-compat.c:126
 ext4_da_write_begin+0x3bb/0xb40 fs/ext4/inode.c:2967
 generic_perform_write+0x249/0x560 mm/filemap.c:3792
 ext4_buffered_write_iter+0x15b/0x330 fs/ext4/file.c:270
 ext4_file_write_iter+0x43c/0x1510 fs/ext4/file.c:679
 call_write_iter include/linux/fs.h:2059 [inline]
 new_sync_write+0x38a/0x560 fs/read_write.c:504
 vfs_write+0x7c0/0xac0 fs/read_write.c:591
 ksys_write+0x127/0x250 fs/read_write.c:644
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fa74a4890e9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa74b62f168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fa74a59bf60 RCX: 00007fa74a4890e9
RDX: 000000000208e24b RSI: 0000000020000000 RDI: 0000000000000006
RBP: 00007fa74a4e308d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe1752d1cf R14: 00007fa74b62f300 R15: 0000000000022000
 </TASK>
----------------
Code disassembly (best guess):
   0:	fa                   	cli
   1:	83 e2 07             	and    $0x7,%edx
   4:	38 d0                	cmp    %dl,%al
   6:	7f 04                	jg     0xc
   8:	84 c0                	test   %al,%al
   a:	75 63                	jne    0x6f
   c:	0f b6 07             	movzbl (%rdi),%eax
   f:	40 38 c6             	cmp    %al,%sil
  12:	74 35                	je     0x49
  14:	48 83 c4 10          	add    $0x10,%rsp
  18:	c3                   	retq
  19:	c3                   	retq
  1a:	e8 23 91 4b 00       	callq  0x4b9142
  1f:	eb 07                	jmp    0x28
  21:	0f 00 2d da b1 94 08 	verw   0x894b1da(%rip)        # 0x894b202
  28:	fb                   	sti
  29:	f4                   	hlt
* 2a:	48 83 c4 10          	add    $0x10,%rsp <-- trapping instruction
  2e:	c3                   	retq
  2f:	89 74 24 0c          	mov    %esi,0xc(%rsp)
  33:	48 89 3c 24          	mov    %rdi,(%rsp)
  37:	e8 56 8f 4b 00       	callq  0x4b8f92
  3c:	8b 74 24 0c          	mov    0xc(%rsp),%esi