syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4619/1:b..l
	(detected by 0, t=10502 jiffies, g=10869, q=468 ncpus=2)
task:syz.2.70        state:R  running task     stack:25712 pid:4619  ppid:4285   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6874
 irqentry_exit+0x63/0x70 kernel/entry/common.c:439
 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696
RIP: 0010:lock_acquire+0x225/0x4a0 kernel/locking/lockdep.c:5666
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f0 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04
RSP: 0018:ffffc90006896ee0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: eda323338337db00
RDX: 0000000000000000 RSI: ffffffff8a8c22a0 RDI: ffffffff8adf1320
RBP: ffffc90006896fe8 R08: dffffc0000000000 R09: 1ffffffff215f248
R10: dffffc0000000000 R11: fffffbfff215f249 R12: 0000000000000001
R13: 1ffff92000d12de8 R14: 0000000000000246 R15: dffffc0000000000
 rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 rcu_read_lock include/linux/rcupdate.h:791 [inline]
 page_ext_get+0x3a/0x2a0 mm/page_ext.c:157
 __set_page_owner+0x24/0x60 mm/page_owner.c:192
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2559
 prep_new_page mm/page_alloc.c:2566 [inline]
 get_page_from_freelist+0x1a1e/0x1ab0 mm/page_alloc.c:4357
 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5657
 __folio_alloc+0xe/0x30 mm/page_alloc.c:5689
 vma_alloc_folio+0x4a3/0x900 mm/mempolicy.c:2243
 alloc_page_vma include/linux/gfp.h:284 [inline]
 wp_page_copy+0x28b/0x1680 mm/memory.c:3146
 handle_pte_fault mm/memory.c:5047 [inline]
 __handle_mm_fault mm/memory.c:5171 [inline]
 handle_mm_fault+0x1d19/0x3ee0 mm/memory.c:5292
 do_user_addr_fault+0x51f/0xb10 arch/x86/mm/fault.c:1338
 handle_page_fault arch/x86/mm/fault.c:1429 [inline]
 exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1482
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0010:__put_user_nocheck_4+0x3/0x11
Code: 00 00 48 39 d9 73 54 0f 01 cb 66 89 01 31 c9 0f 01 ca c3 90 90 90 90 90 48 bb fd ef ff ff ff 7f 00 00 48 39 d9 73 34 0f 01 cb <89> 01 31 c9 0f 01 ca c3 90 90 90 90 90 90 48 bb f9 ef ff ff ff 7f
RSP: 0018:ffffc900068978d8 EFLAGS: 00050202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00002000001fd030
RDX: ffff88802b8f8000 RSI: 0000000000000002 RDI: 00000000ffffffff
RBP: ffffc90006897a70 R08: ffffc900068976c7 R09: 1ffff92000d12ed8
R10: dffffc0000000000 R11: fffff52000d12ed9 R12: dffffc0000000000
R13: 00002000001fd000 R14: 0000000000000000 R15: 0000000000000002
 ____sys_recvmsg+0x3a0/0x5e0 net/socket.c:2750
 ___sys_recvmsg+0x212/0x590 net/socket.c:2779
 do_recvmmsg+0x393/0x870 net/socket.c:2873
 __sys_recvmmsg net/socket.c:2952 [inline]
 __do_sys_recvmmsg net/socket.c:2975 [inline]
 __se_sys_recvmmsg net/socket.c:2968 [inline]
 __x64_sys_recvmmsg+0x195/0x250 net/socket.c:2968
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4cb659ce59
RSP: 002b:00007f4cb73cf028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f4cb6816090 RCX: 00007f4cb659ce59
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f4cb6632d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4cb6816128 R14: 00007f4cb6816090 R15: 00007ffd2871eb08
 </TASK>
rcu: rcu_preempt kthread starved for 9618 jiffies! g10869 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:27504 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
 schedule+0xb9/0x180 kernel/sched/core.c:6638
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168
 rcu_gp_fqs_loop+0x303/0x1340 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 1 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:741