rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5001/1:b..l P15922/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=79633, q=685 ncpus=2)
task:syz-executor state:R running task stack:22056 pid:15922 tgid:15922 ppid:1 task_flags:0x40054c flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7370
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:190
spin_unlock include/linux/spinlock.h:390 [inline]
zap_pte_range mm/memory.c:1964 [inline]
zap_pmd_range mm/memory.c:2020 [inline]
zap_pud_range mm/memory.c:2048 [inline]
zap_p4d_range mm/memory.c:2069 [inline]
__zap_vma_range+0x3d36/0x4b70 mm/memory.c:2109
unmap_vmas+0x3ac/0x570 mm/memory.c:2178
exit_mmap+0x280/0x9e0 mm/mmap.c:1300
__mmput+0x118/0x430 kernel/fork.c:1178
exit_mm+0x1f6/0x2d0 kernel/exit.c:582
do_exit+0x6a2/0x22c0 kernel/exit.c:964
do_group_exit+0x21b/0x2d0 kernel/exit.c:1119
get_signal+0x1284/0x1330 kernel/signal.c:3037
arch_do_signal_or_restart+0xbc/0x840 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0xa9/0x680 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f985395d68e
RSP: 002b:00007ffd3bac3088 EFLAGS: 00000246
RAX: fffffffffffffffc RBX: 0000555594f2c500 RCX: 00007f985395d68e
RDX: 00007ffd3bac30e0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffd3bac314c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000030
R13: 000000000000000f R14: 00000000000805fc R15: 00007ffd3bac31a0
task:udevd state:R running task stack:23288 pid:5001 tgid:5001 ppid:1 task_flags:0x400140 flags:0x00080801
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x14f/0x8b0 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lookup_page_ext mm/page_ext.c:258 [inline]
RIP: 0010:page_ext_get+0x1ab/0x2e0 mm/page_ext.c:532
Code: 31 89 ff eb 05 e8 05 31 89 ff 45 31 ff 49 83 c7 10 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 68 89 f4 ff 4d 8b 3f 00 54 6d ff 89 c5 31 ff 89 c6 e8 15 35 89 ff 85 ed 0f 84 f4 00
RSP: 0018:ffffc9000303fa48 EFLAGS: 00000246
RAX: 1ffff11027fd7c2a RBX: ffffffff823c8442 RCX: ffff88807c01dd00
RDX: 0000000000000000 RSI: 0000000000001000 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffffffff823c8442 R09: ffffffff8e95cc20
R10: dffffc0000000000 R11: fffff94000298dc7 R12: 0000000000000140
R13: dffffc0000000000 R14: 00000000000531b8 R15: ffff88801bb00000
__reset_page_owner+0x28/0x1f0 mm/page_owner.c:306
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1397 [inline]
__free_frozen_pages+0xc1c/0xd30 mm/page_alloc.c:2938
__slab_free+0x274/0x2c0 mm/slub.c:5613
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4570 [inline]
slab_alloc_node mm/slub.c:4899 [inline]
kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4906
alloc_filename fs/namei.c:142 [inline]
do_getname+0x2e/0x250 fs/namei.c:182
getname include/linux/fs.h:2526 [inline]
getname_maybe_null include/linux/fs.h:2533 [inline]
class_filename_maybe_null_constructor include/linux/fs.h:2557 [inline]
vfs_fstatat+0x45/0x170 fs/stat.c:368
__do_sys_newfstatat fs/stat.c:538 [inline]
__se_sys_newfstatat fs/stat.c:532 [inline]
__x64_sys_newfstatat+0x151/0x200 fs/stat.c:532
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4921711b0a
RSP: 002b:00007fff5700bdf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 00005636f2024fa0 RCX: 00007f4921711b0a
RDX: 00007fff5700be00 RSI: 00005636f2024fa0 RDI: 00000000ffffff9c
RBP: 00005636f2013bf0 R08: 00063478c1c69200 R09: 3fffffffffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff5700be00
R13: 00005636d3992100 R14: 0000000000000000 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 10434 jiffies! g79633 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:27544 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
kthread+0x389/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 14 Comm: kworker/R-mm_pe Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: mm_percpu_wq vmstat_update
RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872
Code: ff ff ff e8 31 bf 05 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 0b 5a 96 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 18 ed 91
RSP: 0018:ffffc90000a07d18 EFLAGS: 00000286
RAX: d199e4582a97a000 RBX: 0000000000000000 RCX: 0000000080000100
RDX: 00000000a42637f2 RSI: ffffffff8e2172fd RDI: ffffffff8c28b8e0
RBP: ffffffff8176e256 R08: ffffffff8176e256 R09: ffffffff8e95cc20
R10: ffffc90000a07e78 R11: ffffffff81b0e0e0 R12: 0000000000000002
R13: ffffffff8e95cc20 R14: 0000000000000000 R15: 0000000000000246
FS: 0000000000000000(0000) GS:ffff8881253a0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f11bc6c2cfa CR3: 00000000751fc000 CR4: 00000000003526f0
Call Trace:
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock include/linux/rcupdate.h:838 [inline]
class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
unwind_next_frame+0xc3/0x2550 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4570 [inline]
slab_alloc_node mm/slub.c:4899 [inline]
kmem_cache_alloc_node_noprof+0x384/0x690 mm/slub.c:4951
__alloc_skb+0x1d0/0x7d0 net/core/skbuff.c:702
alloc_skb include/linux/skbuff.h:1385 [inline]
synproxy_send_client_synack+0x172/0xe30 net/netfilter/nf_synproxy_core.c:465
nft_synproxy_eval_v4+0x34a/0x4e0 net/netfilter/nft_synproxy.c:60
nft_synproxy_do_eval+0x305/0x580 net/netfilter/nft_synproxy.c:142
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x48d/0x1ae0 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0x360/0x4b0 net/netfilter/nft_chain_filter.c:162
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619
nf_hook include/linux/netfilter.h:273 [inline]
NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316
NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318
__netif_receive_skb_one_core net/core/dev.c:6202 [inline]
__netif_receive_skb net/core/dev.c:6315 [inline]
process_backlog+0xaa3/0x1950 net/core/dev.c:6666
__napi_poll+0xae/0x340 net/core/dev.c:7733
napi_poll net/core/dev.c:7796 [inline]
net_rx_action+0x627/0xf70 net/core/dev.c:7953
handle_softirqs+0x22a/0x840 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:fold_diff+0x146/0x470 mm/vmstat.c:767
Code: 0f 85 7b 02 00 00 4d 63 3f 4d 85 ff 74 1c 48 c7 c7 a0 44 61 8e be 08 00 00 00 e8 35 4f 21 00 f0 4c 01 3d fd 81 51 0c 40 b5 01 <4d> 8d 7e 14 4c 89 f8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 5d 02
RSP: 0018:ffffc90000137888 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffc900001378f0 RCX: ffffffff820fc1a7
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffff8e614480
RBP: ffffc90000137a01 R08: ffffffff8e614487 R09: 1ffffffff1cc2890
R10: dffffc0000000000 R11: fffffbfff1cc2891 R12: dffffc0000000000
R13: ffff88823fffcdc8 R14: ffffc90000137a00 R15: 0000000000000000
refresh_cpu_vm_stats+0x406/0x440 mm/vmstat.c:879
vmstat_update+0x15/0xb0 mm/vmstat.c:2039
process_one_work kernel/workqueue.c:3314 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
rescuer_thread+0x827/0x1130 kernel/workqueue.c:3621
kthread+0x389/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245