rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1):
 P17984/1:b..l

rcu: 	(detected by 0, t=10502 jiffies, g=119965, q=112 ncpus=2)
task:syz.6.2773      state:R
  running task     stack:24128 pid:17984 tgid:17982 ppid:10470  task_flags:0x400040 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x1b88/0x5240 kernel/sched/core.c:6767
 preempt_schedule_irq+0xfe/0x1c0 kernel/sched/core.c:7090
 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:debug_lockdep_rcu_enabled+0x21/0x40 kernel/rcu/update.c:321
Code: 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 31 c0 83 3d 47 4d 30 04 00 74 1e 83 3d 1a 7b 30 04 00 74 15 65 48 8b 0c 25 08 60 68 93 <31> c0 83 b9 ec 0a 00 00 00 0f 94 c0 c3 cc cc cc cc cc cc cc cc cc
RSP: 0018:ffffc9000b0f6560 EFLAGS: 00000202

RAX: 0000000000000000 RBX: 1ffff9200161ecc8 RCX: ffff8880299d8000
RDX: 0000000000000000 RSI: ffffffff8e4db3f9 RDI: ffffffff8ca1b5c0
RBP: ffffc9000b0f6678 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffc9000b0f6640
R13: dffffc0000000000 R14: ffffffff821e3e74 R15: ffffffff816d9bc8
 rcu_read_lock include/linux/rcupdate.h:842 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
 unwind_next_frame+0xde/0x23b0 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x11e/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x11a/0x1d0 kernel/stacktrace.c:122
 save_stack+0xfc/0x1f0 mm/page_owner.c:156
 __set_page_owner+0x93/0x530 mm/page_owner.c:329
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1718
 prep_new_page mm/page_alloc.c:1726 [inline]
 get_page_from_freelist+0x360a/0x37a0 mm/page_alloc.c:3700
 __alloc_frozen_pages_noprof+0x211/0x5b0 mm/page_alloc.c:4982
 alloc_pages_mpol+0x339/0x690 mm/mempolicy.c:2301
 folio_alloc_mpol_noprof mm/mempolicy.c:2320 [inline]
 vma_alloc_folio_noprof+0x12d/0x260 mm/mempolicy.c:2355
 folio_prealloc+0x2e/0x170 mm/memory.c:-1
 wp_page_copy mm/memory.c:3478 [inline]
 do_wp_page+0x14f6/0x5e00 mm/memory.c:3939
 handle_pte_fault+0xfaf/0x61c0 mm/memory.c:6013
 __handle_mm_fault mm/memory.c:6140 [inline]
 handle_mm_fault+0x1129/0x1bf0 mm/memory.c:6309
 do_user_addr_fault arch/x86/mm/fault.c:1388 [inline]
 handle_page_fault arch/x86/mm/fault.c:1480 [inline]
 exc_page_fault+0x2bb/0x920 arch/x86/mm/fault.c:1538
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0010:__put_user_nocheck_4+0x3/0x10 arch/x86/lib/putuser.S:104
Code: d9 0f 01 cb 89 01 31 c9 0f 01 ca c3 cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 01 cb <89> 01 31 c9 0f 01 ca c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000b0f78f8 EFLAGS: 00050202

RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00002000000ee030
RDX: ffff8880299d8000 RSI: 0000000000000002 RDI: 00000000ffffffff
RBP: ffffc9000b0f7a70 R08: ffffffff89dfc3b4 R09: 1ffff9200161eed4
R10: dffffc0000000000 R11: fffff5200161eed5 R12: 00002000000ee000
R13: 0000000000000002 R14: 0000000000000000 R15: ffffc9000b0f7d00
 ____sys_recvmsg+0x2ac/0x480 net/socket.c:2799
 ___sys_recvmsg net/socket.c:2828 [inline]
 do_recvmmsg+0x428/0xab0 net/socket.c:2923
 __sys_recvmmsg net/socket.c:2997 [inline]
 __do_sys_recvmmsg net/socket.c:3020 [inline]
 __se_sys_recvmmsg net/socket.c:3013 [inline]
 __x64_sys_recvmmsg+0x1ab/0x260 net/socket.c:3013
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa8ce98e169
RSP: 002b:00007fa8cc7f6038 EFLAGS: 00000246
 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fa8cebb6080 RCX: 00007fa8ce98e169
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007fa8cea10a68 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007fa8cebb6080 R15: 00007fa8cecdfa28
 </TASK>
rcu: rcu_preempt kthread starved for 8704 jiffies! g119965 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:26376 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x1b88/0x5240 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x163/0x360 kernel/sched/core.c:6860
 schedule_timeout+0x15b/0x2b0 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x2e1/0x1340 kernel/rcu/tree.c:2046
 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2248
 kthread+0x7b7/0x940 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.15.0-rc2-syzkaller-00400-g3088d26962e8 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:81
Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 53 8e 18 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8ea07d60 EFLAGS: 000002c6

RAX: b83c33edab40ad00 RBX: ffffffff8197272e RCX: ffffffff8c2fa89c
RDX: 0000000000000001 RSI: ffffffff8e64973a RDI: ffffffff8ca1b5c0
RBP: ffffffff8ea07eb8 R08: ffff8880b8632b5b R09: 1ffff110170c656b
R10: dffffc0000000000 R11: ffffed10170c656c R12: 1ffffffff1d40fc6
R13: 1ffffffff1d52cb0 R14: 0000000000000000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888124f9a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdafd4ae5bb CR3: 0000000032db8000 CR4: 00000000003526f0
DR0: 000000000000000e DR1: 000000000000000c DR2: 000000000000000e
DR3: 00000000000000b4 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:748
 default_idle_call+0x74/0xb0 kernel/sched/idle.c:117
 cpuidle_idle_call kernel/sched/idle.c:185 [inline]
 do_idle+0x22e/0x5d0 kernel/sched/idle.c:325
 cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:423
 rest_init+0x2dc/0x300 init/main.c:743
 start_kernel+0x484/0x510 init/main.c:1099
 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:513
 x86_64_start_kernel+0x66/0x70 arch/x86/kernel/head64.c:494
 common_startup_64+0x13e/0x147
 </TASK>