rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1):
 P11998/1:b..l

rcu: 	(detected by 1, t=10502 jiffies, g=43365, q=145 ncpus=2)
task:syz.4.1643      state:R
  running task     stack:25512 pid:11998 tgid:11983 ppid:5805   task_flags:0x400040 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6929
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256
 irqentry_exit+0x36/0x90 kernel/entry/common.c:211
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:ma_pivots lib/maple_tree.c:600 [inline]
RIP: 0010:mtree_range_walk+0x301/0xc00 lib/maple_tree.c:2555
Code: 24 38 e8 62 e3 65 f6 48 8b 44 24 20 48 c7 c6 40 40 f0 8c 48 89 c2 48 c1 e8 03 89 c3 48 89 44 24 30 30 d2 83 e3 0f 48 89 14 24 <89> d8 89 5c 24 08 48 89 c7 48 89 44 24 10 e8 cc de 65 f6 83 fb 02
RSP: 0018:ffffc9000412f668 EFLAGS: 00000206

RAX: 1ffff1100b92ca43 RBX: 0000000000000003 RCX: ffffc9000e331000
RDX: ffff88805c965200 RSI: ffffffff8cf04040 RDI: ffffc9000412f760
RBP: ffffc9000412f788 R08: 0000000000000005 R09: 0000000000000002
R10: 0000000000000000 R11: 0000000000000001 R12: ffffc9000412f780
R13: ffffc9000412f858 R14: ffffc9000412f778 R15: 0000000000000002
 mas_state_walk lib/maple_tree.c:3296 [inline]
 mt_find+0x4c5/0xa20 lib/maple_tree.c:6495
 find_vma+0xbf/0x140 mm/mmap.c:909
 lock_mm_and_find_vma+0x62/0x6e0 mm/mmap_lock.c:431
 do_user_addr_fault+0x2ac/0x1370 arch/x86/mm/fault.c:1359
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x64/0xc0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0010:rep_movs_alternative+0x30/0x90 arch/x86/lib/copy_user_64.S:60
Code: 83 f9 08 73 25 85 c9 74 0f 8a 06 88 07 48 ff c7 48 ff c6 48 ff c9 75 f1 e9 4d 3c 04 00 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 <48> 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 db 83 f9 08
RSP: 0018:ffffc9000412fa48 EFLAGS: 00050206

RAX: 0000000000000001 RBX: 0000200000323000 RCX: 0000000000000038
RDX: fffff52000825f5a RSI: 0000200000323000 RDI: ffffc9000412fa98
RBP: 0000000000000038 R08: 0000000000000001 R09: fffff52000825f59
R10: ffffc9000412facf R11: 0000000000000001 R12: 0000000000000000
R13: ffffc9000412fa98 R14: ffffc9000412fb80 R15: ffffc9000412fa98
 copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline]
 raw_copy_from_user arch/x86/include/asm/uaccess_64.h:141 [inline]
 _inline_copy_from_user include/linux/uaccess.h:178 [inline]
 _copy_from_user+0x98/0xd0 lib/usercopy.c:18
 copy_from_user include/linux/uaccess.h:212 [inline]
 copy_msghdr_from_user+0x98/0x160 net/socket.c:2560
 recvmsg_copy_msghdr net/socket.c:2816 [inline]
 ___sys_recvmsg+0xdb/0x1a0 net/socket.c:2888
 do_recvmmsg+0x2fe/0x750 net/socket.c:2987
 __sys_recvmmsg net/socket.c:3061 [inline]
 __do_sys_recvmmsg net/socket.c:3084 [inline]
 __se_sys_recvmmsg net/socket.c:3077 [inline]
 __x64_sys_recvmmsg+0x22a/0x280 net/socket.c:3077
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc778b8efc9
RSP: 002b:00007fc779a34038 EFLAGS: 00000246
 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fc778de6090 RCX: 00007fc778b8efc9
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000005
RBP: 00007fc778c11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc778de6128 R14: 00007fc778de6090 R15: 00007ffd40b7afa8
 </TASK>
rcu: rcu_preempt kthread starved for 9126 jiffies! g43365 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:29112 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:7026
 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 07 6d 02 c3 cc cc cc cc 0f 1f 00 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 43 d5 29 00 fb f4 <e9> 3c 0a 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197de8 EFLAGS: 000002c6

RAX: 00000000034b1d2d RBX: 0000000000000001 RCX: ffffffff8b6052a9
RDX: 0000000000000000 RSI: ffffffff8da2a287 RDI: ffffffff8bf06e40
RBP: ffffed1003adc490 R08: 0000000000000001 R09: ffffed10170a6655
R10: ffff8880b85332ab R11: 0000000000000001 R12: 0000000000000001
R13: ffff88801d6e2480 R14: ffffffff9081f6d0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888124b0a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8c30557eee CR3: 000000005a302000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:190 [inline]
 do_idle+0x38d/0x500 kernel/sched/idle.c:330
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428
 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315
 common_startup_64+0x13e/0x148
 </TASK>