rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5836/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=11821, q=557 ncpus=2)
task:syz-executor    state:R  running task     stack:21176 pid:5836  tgid:5836  ppid:5828   task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5257 [inline]
 __schedule+0x14bc/0x5030 kernel/sched/core.c:6864
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7191
 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__preempt_count_add kernel/rcu/tree.c:747 [inline]
RIP: 0010:rcu_is_watching+0x6/0xb0 kernel/rcu/tree.c:750
Code: e8 1f 7a 21 03 eb cc 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 <41> 56 53 65 ff 05 70 9c ce 10 e8 1b 2a b4 09 89 c3 83 f8 08 73 65
RSP: 0018:ffffc9000409f1a0 EFLAGS: 00000297
RAX: 0000000000000001 RBX: ffffffff901ca201 RCX: 1afbab9dbab95b00
RDX: ffffc9000409f301 RSI: ffffffff81745035 RDI: ffffffff8df3d980
RBP: dffffc0000000000 R08: ffffc9000409fc58 R09: 0000000000000000
R10: ffffc9000409f338 R11: fffff52000813e69 R12: ffffc9000409fc68
R13: ffffffff81745035 R14: ffffffff8df3d980 R15: ffffffff81745035
 trace_lock_release include/trace/events/lock.h:69 [inline]
 lock_release+0x4b/0x3d0 kernel/locking/lockdep.c:5879
 rcu_lock_release include/linux/rcupdate.h:341 [inline]
 rcu_read_unlock include/linux/rcupdate.h:897 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
 unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 save_stack+0xf5/0x1f0 mm/page_owner.c:165
 __set_page_owner+0x8d/0x4c0 mm/page_owner.c:341
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846
 prep_new_page mm/page_alloc.c:1854 [inline]
 get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3915
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
 alloc_slab_page mm/slub.c:3075 [inline]
 allocate_slab+0x86/0x3b0 mm/slub.c:3248
 new_slab mm/slub.c:3302 [inline]
 ___slab_alloc+0xf56/0x1990 mm/slub.c:4651
 __slab_alloc+0x65/0x100 mm/slub.c:4774
 __slab_alloc_node mm/slub.c:4850 [inline]
 slab_alloc_node mm/slub.c:5246 [inline]
 kmem_cache_alloc_noprof+0x40f/0x700 mm/slub.c:5265
 alloc_vfsmnt+0x23/0x430 fs/namespace.c:303
 clone_mnt+0x4b/0x9a0 fs/namespace.c:1262
 copy_tree+0x3d4/0x930 fs/namespace.c:2210
 do_loopback+0x31d/0x410 fs/namespace.c:3004
 do_mount fs/namespace.c:4057 [inline]
 __do_sys_mount fs/namespace.c:4246 [inline]
 __se_sys_mount+0x313/0x410 fs/namespace.c:4223
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2e4a990eea
RSP: 002b:00007fff186a0758 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f2e4aa143a5 RCX: 00007f2e4a990eea
RDX: 0000000000000000 RSI: 00007f2e4aa143f8 RDI: 00007f2e4aa14409
RBP: 00007f2e4aa143f8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000045000 R11: 0000000000000246 R12: 0000000000000008
R13: 0000000000000003 R14: 00007fff186a0a58 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 10551 jiffies! g11821 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:27064 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5257 [inline]
 __schedule+0x14bc/0x5030 kernel/sched/core.c:6864
 __schedule_loop kernel/sched/core.c:6946 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6961
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </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: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
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 33 70 0c 00 f3 0f 1e fa fb f4 <e9> c8 f2 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6
RAX: a9d0c7780f992e00 RBX: ffffffff8197acb7 RCX: a9d0c7780f992e00
RDX: 0000000000000001 RSI: ffffffff8d78f71d RDI: ffffffff8bbf81e0
RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db
R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8f7deb70
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11003adab70
FS:  0000000000000000(0000) GS:ffff888125fba000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f33c6972a60 CR3: 0000000075c46000 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+0x73/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:190 [inline]
 do_idle+0x1e7/0x510 kernel/sched/idle.c:330
 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x147
 </TASK>