rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5829/1:b..l P7247/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=18917, q=232 ncpus=2)
task:syz.2.386 state:R running task stack:25752 pid:7247 tgid:7246 ppid:5814 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x168f/0x4c70 kernel/sched/core.c:6767
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7090
irqentry_exit+0x6f/0x90 kernel/entry/common.c:354
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:debug_lockdep_rcu_enabled+0xd/0x40 kernel/rcu/update.c:320
Code: cc cc cc cc cc cc 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 31 c0 83 3d 27 dd 2e 04 00 <74> 1e 83 3d ea 0a 2f 04 00 74 15 65 48 8b 0c 25 08 00 72 92 31 c0
RSP: 0018:ffffc9000ebc6cf0 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffffffff9016f501 RCX: ffffc9000ebc7d28
RDX: ffffc9000ebc6e01 RSI: dffffc0000000000 RDI: ffffc9000ebc6dd0
RBP: dffffc0000000000 R08: ffffc9000ebc7d10 R09: 0000000000000000
R10: ffffc9000ebc6e18 R11: fffff52001d78dc5 R12: ffffc9000ebc7d20
R13: ffffc9000ebc0000 R14: ffffc9000ebc6dc8 R15: ffffffff817199f5
rcu_read_unlock include/linux/rcupdate.h:869 [inline]
class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0x195c/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+0xf7/0x1f0 mm/page_owner.c:156
__set_page_owner+0x8d/0x4a0 mm/page_owner.c:329
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1d8/0x230 mm/page_alloc.c:1718
prep_new_page mm/page_alloc.c:1726 [inline]
get_page_from_freelist+0x21c7/0x22a0 mm/page_alloc.c:3688
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4970
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2301
folio_alloc_mpol_noprof+0x39/0x70 mm/mempolicy.c:2320
shmem_alloc_folio mm/shmem.c:1854 [inline]
shmem_alloc_and_add_folio+0x447/0xf60 mm/shmem.c:1893
shmem_get_folio_gfp+0x597/0x15f0 mm/shmem.c:2533
shmem_fault+0x179/0x390 mm/shmem.c:2734
__do_fault+0x135/0x390 mm/memory.c:5098
do_read_fault mm/memory.c:5518 [inline]
do_fault mm/memory.c:5652 [inline]
do_pte_missing mm/memory.c:4160 [inline]
handle_pte_fault mm/memory.c:5997 [inline]
__handle_mm_fault+0x363e/0x5380 mm/memory.c:6140
handle_mm_fault+0x2d5/0x7f0 mm/memory.c:6309
faultin_page mm/gup.c:1193 [inline]
__get_user_pages+0x16f0/0x2a40 mm/gup.c:1491
populate_vma_page_range+0x26b/0x340 mm/gup.c:1929
__mm_populate+0x24c/0x380 mm/gup.c:2032
mm_populate include/linux/mm.h:3487 [inline]
vm_mmap_pgoff+0x3f0/0x4c0 mm/util.c:584
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2653f8e969
RSP: 002b:00007f2651df6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f26541b5fa0 RCX: 00007f2653f8e969
RDX: 0000000000000002 RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f2654010ab1 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f26541b5fa0 R15: 00007ffe64804058
task:syz-executor state:R running task stack:21336 pid:5829 tgid:5829 ppid:5810 task_flags:0x400140 flags:0x00000000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x168f/0x4c70 kernel/sched/core.c:6767
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7090
irqentry_exit+0x6f/0x90 kernel/entry/common.c:354
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline]
RIP: 0010:lock_release+0x46/0x3e0 kernel/locking/lockdep.c:5877
Code: f0 e3 d3 10 48 89 44 24 28 0f 1f 44 00 00 65 8b 05 f3 e3 d3 10 83 f8 08 0f 83 9a 02 00 00 89 c0 48 0f a3 05 1c 8e df 0d 73 16 c5 c8 08 00 84 c0 75 0d f6 05 d1 8b c9 0d 01 0f 84 ad 02 00 00
RSP: 0018:ffffc900040df830 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff8880533bda00
RDX: 0000000000000000 RSI: ffffffff8234599f RDI: ffffffff8df3b860
RBP: ffffc900040dfaa0 R08: ffff88806660cc7b R09: 1ffff1100ccc198f
R10: dffffc0000000000 R11: ffffed100ccc1990 R12: ffffc900040dfac0
R13: ffffffff8234599f R14: ffffffff8df3b860 R15: dffffc0000000000
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
leave_rcu+0xfb/0x160 fs/namei.c:744
try_to_unlazy+0x2e0/0x580 fs/namei.c:852
may_lookup fs/namei.c:1854 [inline]
link_path_walk+0x7ee/0xe50 fs/namei.c:2451
path_lookupat+0x97/0x430 fs/namei.c:2659
filename_lookup+0x212/0x570 fs/namei.c:2689
vfs_statx+0xfb/0x550 fs/stat.c:350
vfs_fstatat+0xe4/0x160 fs/stat.c:372
__do_sys_newfstatat fs/stat.c:536 [inline]
__se_sys_newfstatat fs/stat.c:530 [inline]
__x64_sys_newfstatat+0x11c/0x1a0 fs/stat.c:530
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa2d798d17a
RSP: 002b:00007ffc9ee54a48 EFLAGS: 00000286 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 00007fa2d7a1089d RCX: 00007fa2d798d17a
RDX: 00007ffc9ee54a70 RSI: 00007ffc9ee54b00 RDI: 00000000ffffff9c
RBP: 00007ffc9ee54b00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000286 R12: 00007ffc9ee55b90
R13: 00007fa2d7a1089d R14: 000000000002f6d1 R15: 00007ffc9ee55bd0
rcu: rcu_preempt kthread starved for 10031 jiffies! g18917 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:27304 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x168f/0x4c70 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6860
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2046
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2248
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
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 Not tainted 6.15.0-rc4-syzkaller-00042-gb6ea1680d0ac #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:81
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 03 4b 19 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6
RAX: 5b072bff4f0f3100 RBX: ffffffff81973cc8 RCX: 5b072bff4f0f3100
RDX: 0000000000000001 RSI: ffffffff8d73674f RDI: ffffffff8bc0fa60
RBP: ffffc90000197f20 R08: ffff8880b8932b5b R09: 1ffff1101712656b
R10: dffffc0000000000 R11: ffffed101712656c R12: ffffffff8f7daa70
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff110038dab40
FS: 0000000000000000(0000) GS:ffff888126200000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe617758bd0 CR3: 000000007eeda000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:748
default_idle_call+0x74/0xb0 kernel/sched/idle.c:117
cpuidle_idle_call kernel/sched/idle.c:185 [inline]
do_idle+0x1e8/0x510 kernel/sched/idle.c:325
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
common_startup_64+0x13e/0x147