rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P15207/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=73501, q=423 ncpus=2)
task:syz.4.1756 state:R running task stack:26360 pid:15207 tgid:15204 ppid:11680 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288
irqentry_exit+0x36/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872
Code: dd 3d 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 e2 cf 13 0f 0f 82 74 02 00 00 8b 35 8a 01 14 0f 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 39 dd 3d 12 0f 85 c7 02 00 00 48 83 c4
RSP: 0018:ffffc90018e0ec40 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e5c0fe0 RCX: 000000009c22ba9f
RDX: 0000000000000000 RSI: ffffffff8de23985 RDI: ffffffff8c161580
RBP: 0000000000000002 R08: 437f0b3048eb3a99 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xd1/0x20a0 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+0x91/0x550 mm/page_owner.c:329
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1851
prep_new_page mm/page_alloc.c:1859 [inline]
get_page_from_freelist+0x132b/0x38e0 mm/page_alloc.c:3858
__alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:5148
alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416
folio_alloc_mpol_noprof+0x36/0x2f0 mm/mempolicy.c:2435
shmem_alloc_folio+0x135/0x160 mm/shmem.c:1908
shmem_alloc_and_add_folio+0x499/0xc20 mm/shmem.c:1947
shmem_get_folio_gfp+0x67f/0x1600 mm/shmem.c:2597
shmem_fault+0x1fe/0xa30 mm/shmem.c:2798
__do_fault+0x10a/0x490 mm/memory.c:5152
do_shared_fault mm/memory.c:5637 [inline]
do_fault mm/memory.c:5711 [inline]
do_pte_missing+0x1a6/0x3ba0 mm/memory.c:4234
handle_pte_fault mm/memory.c:6052 [inline]
__handle_mm_fault+0x152a/0x2a50 mm/memory.c:6195
handle_mm_fault+0x589/0xd10 mm/memory.c:6364
faultin_page mm/gup.c:1144 [inline]
__get_user_pages+0x551/0x34a0 mm/gup.c:1446
__get_user_pages_locked mm/gup.c:1712 [inline]
faultin_page_range+0x338/0x940 mm/gup.c:1932
madvise_populate mm/madvise.c:979 [inline]
madvise_do_behavior+0x34c/0x530 mm/madvise.c:1883
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/0x490 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8d8338ebe9
RSP: 002b:00007f8d841b0038 EFLAGS: 00000246 ORIG_RAX: 000000000000001c
RAX: ffffffffffffffda RBX: 00007f8d835b6180 RCX: 00007f8d8338ebe9
RDX: 0000000000000017 RSI: ffffffffffff0005 RDI: 0000000000000000
RBP: 00007f8d83411e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8d835b6218 R14: 00007f8d835b6180 R15: 00007fffea7b9ef8
rcu: rcu_preempt kthread starved for 10554 jiffies! g73501 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:27784 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7058
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
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 Tainted: G U 6.16.0-syzkaller-11895-gcca7a0aae895 #0 PREEMPT(full)
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: ec 65 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 c3 91 1a 00 fb f4 3c 0d 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df8 EFLAGS: 000002c6
RAX: 000000000045f84d RBX: 0000000000000001 RCX: ffffffff8b8f7bf9
RDX: 0000000000000000 RSI: ffffffff8de48ce4 RDI: ffffffff8c161580
RBP: ffffed1003c55b40 R08: 0000000000000001 R09: ffffed10170a6655
R10: ffff8880b85332ab R11: 0000000000000000 R12: 0000000000000001
R13: ffff88801e2ada00 R14: ffffffff90ab3290 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881247cc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff63a5b2e80 CR3: 0000000077fbc000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:757
default_idle_call+0x6d/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x391/0x510 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