rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=961c/1/0x4000000000000000 softirq=35994/35995 fqs=0
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7961/1:b..l
rcu: (detected by 1, t=10505 jiffies, g=21885, q=283 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 7952 Comm: syz.3.523 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:num_possible_cpus include/linux/cpumask.h:1222 [inline]
RIP: 0010:mm_get_cid kernel/sched/sched.h:3759 [inline]
RIP: 0010:sched_mm_cid_fork+0x4f2/0xcc0 kernel/sched/core.c:10578
Code: d7 8d 48 b8 00 00 00 00 00 fc ff df 49 c1 ef 03 4c 01 f8 48 89 04 24 eb 5d 49 c7 c4 74 d6 d7 8d 41 83 e4 07 41 83 c4 03 f3 90 <48> 8b 04 24 0f b6 00 41 38 c4 7c 08 84 c0 0f 85 60 06 00 00 8b 35
RSP: 0000:ffffc9001decfd50 EFLAGS: 00000046
RAX: 0000000000000002 RBX: ffff88807a7897d0 RCX: 1ffff1100f4f11a9
RDX: 0000000000000002 RSI: 0000000000000002 RDI: ffff88807a7897d0
RBP: ffff88802c740000 R08: 0000000000000000 R09: fffff52003bd9f9c
R10: 0000000000000003 R11: ffff88802c740b30 R12: 0000000000000007
R13: ffff88807a788dc0 R14: 0000000000000002 R15: 0000000000000002
FS: 00007f72a61f46c0(0000) GS:ffff8881248f1000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c37e912 CR3: 0000000077819000 CR4: 00000000003526f0
Call Trace:
bprm_execve fs/exec.c:1776 [inline]
bprm_execve+0x4ff/0x1620 fs/exec.c:1729
do_execveat_common.isra.0+0x4a5/0x610 fs/exec.c:1859
do_execveat fs/exec.c:1944 [inline]
__do_sys_execveat fs/exec.c:2018 [inline]
__se_sys_execveat fs/exec.c:2012 [inline]
__x64_sys_execveat+0xda/0x120 fs/exec.c:2012
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f72a538f749
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:00007f72a61f4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000142
RAX: ffffffffffffffda RBX: 00007f72a55e5fa0 RCX: 00007f72a538f749
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000004
RBP: 00007f72a5413f91 R08: 0000000000001000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f72a55e6038 R14: 00007f72a55e5fa0 R15: 00007ffe4c31d688
task:syz.1.526 state:R running task stack:26088 pid:7961 tgid:7956 ppid:5809 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:228 [inline]
RIP: 0010:unwind_next_frame+0x204/0x20b0 arch/x86/kernel/unwind_orc.c:510
Code: 00 00 00 fc ff df 89 c1 48 8d 3c 8d 50 c6 dc 91 49 89 f8 49 c1 e8 03 45 0f b6 04 10 48 89 fa 83 e2 07 83 c2 03 44 38 c2 7c 2f <45> 84 c0 74 2a 48 89 4c 24 30 48 89 44 24 28 89 74 24 20 89 44 24
RSP: 0018:ffffc9000f976cf8 EFLAGS: 00000206
RAX: 0000000000010dc6 RBX: 0000000000000001 RCX: 0000000000010dc6
RDX: 0000000000000003 RSI: 00000000000a7cc5 RDI: ffffffff91e0fd68
RBP: ffffc9000f976db0 R08: 0000000000000000 R09: 00000000255fd699
R10: 0000000000000002 R11: 0000000000010dc6 R12: ffffc9000f976db8
R13: ffffc9000f976d68 R14: ffffc9000f976d9d R15: ffffffff820dc693
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:165
__set_page_owner+0x91/0x560 mm/page_owner.c:341
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1884
prep_new_page mm/page_alloc.c:1892 [inline]
get_page_from_freelist+0xd0b/0x31a0 mm/page_alloc.c:3945
__alloc_frozen_pages_noprof+0x25f/0x2430 mm/page_alloc.c:5240
alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486
folio_alloc_mpol_noprof+0x36/0x2f0 mm/mempolicy.c:2505
shmem_alloc_folio+0x135/0x160 mm/shmem.c:1890
shmem_alloc_and_add_folio+0x494/0xc20 mm/shmem.c:1932
shmem_get_folio_gfp+0x67f/0x1610 mm/shmem.c:2556
shmem_fault+0x1fe/0xa00 mm/shmem.c:2757
__do_fault+0x10d/0x490 mm/memory.c:5320
do_read_fault mm/memory.c:5755 [inline]
do_fault+0xae4/0x1ad0 mm/memory.c:5889
do_pte_missing mm/memory.c:4401 [inline]
handle_pte_fault mm/memory.c:6273 [inline]
__handle_mm_fault+0x1919/0x2bb0 mm/memory.c:6411
handle_mm_fault+0x3fe/0xad0 mm/memory.c:6580
faultin_page mm/gup.c:1126 [inline]
__get_user_pages+0x54e/0x3590 mm/gup.c:1428
populate_vma_page_range+0x267/0x3f0 mm/gup.c:1860
__mm_populate+0x1d8/0x380 mm/gup.c:1963
mm_populate include/linux/mm.h:3701 [inline]
vm_mmap_pgoff+0x37f/0x470 mm/util.c:586
ksys_mmap_pgoff+0x7d/0x5c0 mm/mmap.c:604
__do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
__se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
__x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f452bb8f749
RSP: 002b:00007f452c95e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f452bde6090 RCX: 00007f452bb8f749
RDX: 0000000002000004 RSI: 0000000000c00000 RDI: 0000200000001000
RBP: 00007f452bc13f91 R08: ffffffffffffffff R09: 0000000000000000
R10: 000000000003b071 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f452bde6128 R14: 00007f452bde6090 R15: 00007ffeccae1cc8
rcu: rcu_preempt kthread starved for 10505 jiffies! g21885 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:28360 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
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+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
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+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 26 5f 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 13 99 11 00 fb f4 cc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0000:ffffc90000197de8 EFLAGS: 000002c6
RAX: 00000000008419fb RBX: 0000000000000001 RCX: ffffffff8b78c6d9
RDX: 0000000000000000 RSI: ffffffff8dacf709 RDI: ffffffff8bf2b580
RBP: ffffed1003b57498 R08: 0000000000000001 R09: ffffed10170a673d
R10: ffff8880b85339eb R11: ffff88801dabaff0 R12: 0000000000000001
R13: ffff88801daba4c0 R14: ffffffff9088cdd0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881249f1000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3cb8bd CR3: 0000000077c25000 CR4: 00000000003526f0
Call Trace:
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:191 [inline]
do_idle+0x38d/0x510 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x148