rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P11874/1:b..l
rcu: 	(detected by 0, t=10504 jiffies, g=21673, q=114 ncpus=2)
task:syz.1.757       state:R  running task     stack:26376 pid:11874 tgid:11873 ppid:5815   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_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872
Code: e6 08 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 22 4d e9 0e 0f 82 74 02 00 00 8b 35 9a 7d e9 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 39 e6 08 12 0f 85 c7 02 00 00 48 83 c4
RSP: 0018:ffffc9000c276f10 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e3c4760 RCX: 00000000704cbb28
RDX: 0000000000000000 RSI: ffffffff8da06b82 RDI: ffffffff8bf073c0
RBP: 0000000000000002 R08: fd5b3b4fdb4dbf52 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:867 [inline]
 __page_table_check_zero+0x13d/0x5d0 mm/page_table_check.c:138
 page_table_check_alloc include/linux/page_table_check.h:35 [inline]
 post_alloc_hook+0x19e/0x220 mm/page_alloc.c:1846
 prep_new_page mm/page_alloc.c:1853 [inline]
 get_page_from_freelist+0x10a3/0x3a30 mm/page_alloc.c:3879
 __alloc_frozen_pages_noprof+0x25f/0x2470 mm/page_alloc.c:5178
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416
 folio_alloc_mpol_noprof+0x36/0x2f0 mm/mempolicy.c:2435
 vma_alloc_folio_noprof+0xed/0x1e0 mm/mempolicy.c:2470
 folio_prealloc mm/memory.c:1190 [inline]
 wp_page_copy mm/memory.c:3680 [inline]
 do_wp_page+0x11d8/0x52b0 mm/memory.c:4141
 handle_pte_fault mm/memory.c:6211 [inline]
 __handle_mm_fault+0x1ae3/0x2aa0 mm/memory.c:6336
 handle_mm_fault+0x589/0xd10 mm/memory.c:6505
 do_user_addr_fault+0x7a6/0x1370 arch/x86/mm/fault.c:1387
 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:__put_user_nocheck_4+0x3/0x10 arch/x86/lib/putuser.S:104
Code: d9 0f 01 cb 89 01 31 c9 0f 01 ca e9 97 80 03 00 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:ffffc9000c2779e8 EFLAGS: 00050246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000020000027d030
RDX: 0000000000080000 RSI: ffffffff89278903 RDI: 0000000000000005
RBP: ffffc9000c277d88 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000
R13: 000020000027d000 R14: ffffc9000c277dcc R15: 0000000000000002
 ____sys_recvmsg+0x2ee/0x6b0 net/socket.c:2863
 ___sys_recvmsg+0x114/0x1a0 net/socket.c:2892
 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: 0033:0x7f0b6cb8f749
RSP: 002b:00007f0b6d946038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f0b6cde5fa0 RCX: 00007f0b6cb8f749
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f0b6cc13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0b6cde6038 R14: 00007f0b6cde5fa0 R15: 00007ffcfc2e9d08
 </TASK>
rcu: rcu_preempt kthread starved for 10496 jiffies! g21673 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:28080 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 11897 Comm: syz.4.762 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__sanitizer_cov_trace_pc+0x66/0x70 kernel/kcov.c:235
Code: 82 58 16 00 00 83 f8 02 75 20 48 8b 8a 60 16 00 00 8b 92 5c 16 00 00 48 8b 01 48 83 c0 01 48 39 d0 73 07 48 89 01 48 89 34 c1 <c3> cc cc cc cc 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000a08d88 EFLAGS: 00000046
RAX: 0000000000010002 RBX: ffff888032071340 RCX: ffffffff896c9264
RDX: ffff888030410000 RSI: ffffffff896c9272 RDI: 0000000000000006
RBP: ffff88805df74400 R08: 0000000000000006 R09: 1888fb7edc000000
R10: 0000000000000000 R11: 0000000000000001 R12: 1888fb7edc000000
R13: 0000000000000000 R14: ffff8880474ba800 R15: ffffffff896c9030
FS:  00007fde124e86c0(0000) GS:ffff888124b05000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fde124e7f98 CR3: 000000005f52a000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 should_restart_cycle net/sched/sch_taprio.c:874 [inline]
 advance_sched+0x242/0xc80 net/sched/sch_taprio.c:953
 __run_hrtimer kernel/time/hrtimer.c:1777 [inline]
 __hrtimer_run_queues+0x202/0xad0 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
 __sysvec_apic_timer_interrupt+0x10b/0x3f0 arch/x86/kernel/apic/apic.c:1058
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1052
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 26 48 35 f6 48 89 df e8 0e 9c 35 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 <bf> 01 00 00 00 e8 35 a4 25 f6 65 8b 05 7e 35 3e 08 85 c0 74 16 5b
RSP: 0018:ffffc9000c2a7b70 EFLAGS: 00000246
RAX: 0000000000000006 RBX: ffff8880b8427c80 RCX: 0000000000000007
RDX: 0000000000000000 RSI: ffffffff8da2c59c RDI: ffffffff8bf073c0
RBP: 0000000000000283 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff908216d7 R11: 0000000000000001 R12: 0000000000000000
R13: 3647d08007143378 R14: dffffc0000000000 R15: ffff8880b8427c80
 clock_was_set+0x599/0x870 kernel/time/hrtimer.c:965
 do_adjtimex+0x221/0x330 kernel/time/timekeeping.c:2753
 do_clock_adjtime kernel/time/posix-timers.c:1161 [inline]
 __do_sys_clock_adjtime+0x175/0x290 kernel/time/posix-timers.c:1173
 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: 0033:0x7fde1158f749
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fde124e8038 EFLAGS: 00000246 ORIG_RAX: 0000000000000131
RAX: ffffffffffffffda RBX: 00007fde117e6090 RCX: 00007fde1158f749
RDX: 0000000000000000 RSI: 0000200000000280 RDI: 0000000000000000
RBP: 00007fde11613f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fde117e6128 R14: 00007fde117e6090 R15: 00007fff2fc480c8
 </TASK>