syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P10632/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=229349, q=220 ncpus=2)
task:syz.5.11080     state:R  running task     stack:24024 pid:10632 tgid:10627 ppid:2478   task_flags:0x400840 flags:0x00080000
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:__rcu_read_unlock+0x0/0x550 kernel/rcu/tree_plugin.h:431
Code: f8 e8 14 4b ff ff 48 89 df 5b e9 eb de ff ff e8 e6 8a 82 00 eb e7 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 41 56 41 55 41 54 55 65 48 8b 2d 95 52 fe 11 53 48 8d
RSP: 0018:ffffc90003c76358 EFLAGS: 00000296
RAX: 0000000000000000 RBX: ffffc90003c77108 RCX: ffffc90003c76324
RDX: 0000000000000002 RSI: ffffffff8da0489d RDI: ffffffff8bf06e40
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 000000000000fd5d R12: ffffc90003c76420
R13: ffffc90003c763d0 R14: ffffc90003c77108 R15: ffffc90003c76404
 rcu_read_unlock include/linux/rcupdate.h:899 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
 unwind_next_frame+0x3fe/0x20a0 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 save_stack+0x160/0x1f0 mm/page_owner.c:156
 __set_page_owner+0x91/0x560 mm/page_owner.c:332
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1850
 prep_new_page mm/page_alloc.c:1858 [inline]
 get_page_from_freelist+0x10a3/0x3a30 mm/page_alloc.c:3884
 __alloc_frozen_pages_noprof+0x25f/0x2470 mm/page_alloc.c:5183
 __alloc_pages_noprof+0xb/0x1b0 mm/page_alloc.c:5217
 __alloc_pages_node_noprof include/linux/gfp.h:284 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:311 [inline]
 alloc_zpdesc mm/zsmalloc.c:237 [inline]
 alloc_zspage mm/zsmalloc.c:984 [inline]
 zs_malloc+0x500/0x1300 mm/zsmalloc.c:1300
 zswap_compress mm/zswap.c:910 [inline]
 zswap_store_page mm/zswap.c:1429 [inline]
 zswap_store+0xbbf/0x2830 mm/zswap.c:1540
 swap_writeout+0x3f4/0x1090 mm/page_io.c:275
 writeout mm/vmscan.c:662 [inline]
 pageout mm/vmscan.c:721 [inline]
 shrink_folio_list+0x3e50/0x4800 mm/vmscan.c:1453
 reclaim_folio_list+0xda/0x5d0 mm/vmscan.c:2233
 reclaim_pages+0x3ec/0x570 mm/vmscan.c:2270
 madvise_cold_or_pageout_pte_range+0x14e5/0x20d0 mm/madvise.c:565
 walk_pmd_range mm/pagewalk.c:130 [inline]
 walk_pud_range mm/pagewalk.c:224 [inline]
 walk_p4d_range mm/pagewalk.c:262 [inline]
 walk_pgd_range+0xc05/0x1f50 mm/pagewalk.c:303
 __walk_page_range+0x163/0x820 mm/pagewalk.c:410
 walk_page_range_vma+0x2c7/0xa20 mm/pagewalk.c:717
 madvise_pageout_page_range mm/madvise.c:624 [inline]
 madvise_pageout+0x257/0x540 mm/madvise.c:649
 madvise_vma_behavior+0xb14/0x2d50 mm/madvise.c:1352
 madvise_walk_vmas+0x31f/0x9c0 mm/madvise.c:1669
 madvise_do_behavior+0x1e2/0x530 mm/madvise.c:1885
 do_madvise+0x176/0x240 mm/madvise.c:1978
 __do_sys_madvise mm/madvise.c:1987 [inline]
 __se_sys_madvise mm/madvise.c:1985 [inline]
 __x64_sys_madvise+0xa9/0x110 mm/madvise.c:1985
 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: 0033:0x7f192298efc9
RSP: 002b:00007f1920bb4038 EFLAGS: 00000246 ORIG_RAX: 000000000000001c
RAX: ffffffffffffffda RBX: 00007f1922be6180 RCX: 00007f192298efc9
RDX: 0000000000000015 RSI: 0000000000600000 RDI: 0000200000000000
RBP: 00007f1922a11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1922be6218 R14: 00007f1922be6180 R15: 00007ffd85587378
 </TASK>
rcu: rcu_preempt kthread starved for 10425 jiffies! g229349 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:28024 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: 0 UID: 0 PID: 0 Comm: swapper/0 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:ffffffff8e007df8 EFLAGS: 000002c6
RAX: 000000000b6ca9fd RBX: 0000000000000000 RCX: ffffffff8b6052a9
RDX: 0000000000000000 RSI: ffffffff8da2a259 RDI: ffffffff8bf06e40
RBP: fffffbfff1c12f40 R08: 0000000000000001 R09: ffffed1017086655
R10: ffff8880b84332ab R11: 0000000000000001 R12: 0000000000000000
R13: ffffffff8e097a00 R14: ffffffff9081f6d0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888124a0a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b320fdff8 CR3: 000000007f68b000 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
 rest_init+0x16b/0x2b0 init/main.c:757
 start_kernel+0x3f6/0x4e0 init/main.c:1111
 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310
 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291
 common_startup_64+0x13e/0x148
 </TASK>