rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P7966/1:b..l
rcu: 	(detected by 1, t=10503 jiffies, g=31121, q=441 ncpus=2)
task:syz.3.615       state:R  running task     stack:25832 pid:7966  ppid:5787   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009
 irqentry_exit+0x67/0x70 kernel/entry/common.c:438
 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:692
RIP: 0010:__rcu_read_unlock+0x6/0xd0 kernel/rcu/tree_plugin.h:419
Code: eb fa 89 d9 80 e1 07 80 c1 03 38 c1 7c e3 48 89 df e8 9e 77 6c 00 eb d9 66 2e 0f 1f 84 00 00 00 00 00 66 90 f3 0f 1e fa 41 57 <41> 56 41 55 41 54 53 49 bf 00 00 00 00 00 fc ff df 65 48 8b 3d 31
RSP: 0018:ffffc90003837530 EFLAGS: 00000287
RAX: ffffffff8a5ba9e9 RBX: ffffffff8a5ba7ee RCX: 0000000000080000
RDX: ffffc9000dcde000 RSI: 0000000000079fc8 RDI: 0000000000079fc9
RBP: ffffc90003837650 R08: ffff88801b395a00 R09: 0000000000000002
R10: 0000000000000406 R11: 0000000000000002 R12: ffffc900038375a0
R13: ffff8880312f5900 R14: 0000000000000001 R15: ffffffffffffffff
 rcu_read_unlock include/linux/rcupdate.h:818 [inline]
 mt_find+0x398/0x5b0 lib/maple_tree.c:6565
 find_vma+0x12e/0x1b0 mm/mmap.c:1888
 lock_mm_and_find_vma+0x5f/0x300 mm/memory.c:5421
 do_user_addr_fault+0x36c/0x12e0 arch/x86/mm/fault.c:1345
 handle_page_fault arch/x86/mm/fault.c:1465 [inline]
 exc_page_fault+0x67/0x110 arch/x86/mm/fault.c:1521
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0010:__put_user_nocheck_4+0x7/0x10 arch/x86/lib/putuser.S:98
Code: 01 ca c3 f3 0f 1e fa 48 89 cb 48 c1 fb 3f 48 09 d9 0f 01 cb 89 01 31 c9 0f 01 ca c3 90 90 90 90 90 90 90 f3 0f 1e fa 0f 01 cb <89> 01 31 c9 0f 01 ca c3 90 f3 0f 1e fa 48 89 cb 48 c1 fb 3f 48 09
RSP: 0018:ffffc900038378d8 EFLAGS: 00050202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000020000005a030
RDX: ffff88801b395a00 RSI: 0000000000000002 RDI: 00000000ffffffff
RBP: ffffc90003837a70 R08: ffffc90003837687 R09: 1ffff92000706ed0
R10: dffffc0000000000 R11: fffff52000706ed1 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000002 R15: 000020000005a000
 ____sys_recvmsg+0x388/0x5b0 net/socket.c:2827
 ___sys_recvmsg+0x1b6/0x510 net/socket.c:2856
 do_recvmmsg+0x360/0x7d0 net/socket.c:2950
 __sys_recvmmsg net/socket.c:3029 [inline]
 __do_sys_recvmmsg net/socket.c:3052 [inline]
 __se_sys_recvmmsg net/socket.c:3045 [inline]
 __x64_sys_recvmmsg+0x191/0x240 net/socket.c:3045
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f839198eba9
RSP: 002b:00007f83927c6038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f8391bd6090 RCX: 00007f839198eba9
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000005
RBP: 00007f8391a11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8391bd6128 R14: 00007f8391bd6090 R15: 00007fffbfff06c8
 </TASK>
rcu: rcu_preempt kthread starved for 10364 jiffies! g31121 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:27752 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 schedule+0xbd/0x170 kernel/sched/core.c:6773
 schedule_timeout+0x160/0x280 kernel/time/timer.c:2167
 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667
 rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:148
Code: cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d a3 18 3a 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 66 0f 1f 00 55 41 57 41 56
RSP: 0018:ffffffff8ca07d80 EFLAGS: 000002c2
RAX: 1172fee84401fe00 RBX: ffffffff8161925b RCX: 1172fee84401fe00
RDX: 0000000000000001 RSI: ffffffff8aaabca0 RDI: ffffffff8afc72c0
RBP: ffffffff8ca07eb8 R08: ffff8880b8e36d6b R09: 1ffff110171c6dad
R10: dffffc0000000000 R11: ffffed10171c6dae R12: ffffffff8e4a94e8
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1952670
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0bc47d6098 CR3: 000000005dda2000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:753
 default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97
 cpuidle_idle_call kernel/sched/idle.c:170 [inline]
 do_idle+0x1eb/0x510 kernel/sched/idle.c:282
 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:380
 rest_init+0x2e2/0x300 init/main.c:732
 arch_call_rest_init+0xe/0x10 init/main.c:829
 start_kernel+0x459/0x4e0 init/main.c:1074
 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
 x86_64_start_kernel+0x60/0x60 arch/x86/kernel/head64.c:536
 secondary_startup_64_no_verify+0x179/0x17b
 </TASK>