rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9400/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=53045, q=1025819 ncpus=2)
task:syz.0.985 state:R running task stack:24648 pid:9400 tgid:9400 ppid:7675 task_flags:0x40044c flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5533 [inline]
__schedule+0x17db/0x58f0 kernel/sched/core.c:7284
preempt_schedule_common+0x7f/0xd0 kernel/sched/core.c:7463
preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:201 [inline]
_raw_spin_unlock+0x41/0x50 kernel/locking/spinlock.c:213
spin_unlock include/linux/spinlock.h:401 [inline]
zap_pte_range mm/memory.c:2095 [inline]
zap_pmd_range mm/memory.c:2151 [inline]
zap_pud_range mm/memory.c:2179 [inline]
zap_p4d_range mm/memory.c:2200 [inline]
__zap_vma_range+0x40e1/0x4f80 mm/memory.c:2240
unmap_vmas+0x390/0x550 mm/memory.c:2309
exit_mmap+0x293/0x9f0 mm/mmap.c:1315
__mmput+0x118/0x420 kernel/fork.c:1193
exit_mm+0x18e/0x240 kernel/exit.c:592
do_exit+0x6cd/0x2360 kernel/exit.c:974
do_group_exit+0x22d/0x2f0 kernel/exit.c:1129
get_signal+0x121b/0x12c0 kernel/signal.c:3112
arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x10e/0x770 kernel/entry/common.c:101
__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:343 [inline]
do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f085419e199
RSP: 002b:00007f085454fba8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f0854427da0 RCX: 00007f085419e199
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f0854427da0 R08: 0000000000000006 R09: 0000000000000000
R10: 00007f0854427cb0 R11: 0000000000000246 R12: 000000000004ae9c
R13: 00007f085442609c R14: 000000000004ac85 R15: 00007f0854426090
rcu: rcu_preempt kthread starved for 8986 jiffies! g53045 f0x2 RCU_GP_WAIT_FQS(5) ->state=R ->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:27496 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5533 [inline]
__schedule+0x17db/0x58f0 kernel/sched/core.c:7284
__schedule_loop kernel/sched/core.c:7361 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7376
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2122
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2330
kthread+0x38b/0x480 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: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:lock_acquire+0x232/0x350 kernel/locking/lockdep.c:5947
Code: ff ff ff e8 20 ee 43 0a f7 44 24 10 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 82 38 f2 11 48 3b 44 24 50 75 33 fb 48 83 c4 58 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 37 39 da
RSP: 0018:ffffc90000006980 EFLAGS: 00000292
RAX: 5862cbbcbbfeb200 RBX: 0000000000000000 RCX: 8000000000000101
RDX: 000000004dbb4af1 RSI: ffffffff8e69fc58 RDI: ffffffff8c6dad80
RBP: ffffffff8ea8f000 R08: ffffffff817811df R09: 0000000000000000
R10: ffffc90000006ab8 R11: ffffffff81b2c4a0 R12: ffffffff8ed5c8a0
R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000246
FS: 0000000000000000(0000) GS:ffff888124cc6000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1ad9cca223 CR3: 000000001205e000 CR4: 00000000003526f0
Call Trace:
rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
rcu_read_lock include/linux/rcupdate.h:849 [inline]
class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
unwind_next_frame+0xac/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:351 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:377
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4683 [inline]
slab_alloc_node mm/slub.c:4996 [inline]
kmem_cache_alloc_noprof+0x2b9/0x600 mm/slub.c:5010
dst_alloc+0x105/0x170 net/core/dst.c:90
rt_dst_alloc net/ipv4/route.c:1681 [inline]
__mkroute_output net/ipv4/route.c:2684 [inline]
ip_route_output_key_hash_rcu+0x14ac/0x2720 net/ipv4/route.c:2904
ip_route_output_key_hash+0x18d/0x2a0 net/ipv4/route.c:2734
__ip_route_output_key include/net/route.h:169 [inline]
ip_route_output_flow+0x2a/0x150 net/ipv4/route.c:2961
ip_route_output_key include/net/route.h:179 [inline]
ip_route_me_harder+0x762/0xfe0 net/ipv4/netfilter.c:54
synproxy_send_tcp+0x332/0x670 net/netfilter/nf_synproxy_core.c:434
synproxy_send_client_synack+0x89b/0xde0 net/netfilter/nf_synproxy_core.c:487
nft_synproxy_eval_v4+0x362/0x4e0 net/netfilter/nft_synproxy.c:59
nft_synproxy_do_eval+0x389/0x5d0 net/netfilter/nft_synproxy.c:142
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x48d/0x1b10 net/netfilter/nf_tables_core.c:285
nft_do_chain_ipv4+0x195/0x290 net/netfilter/nft_chain_filter.c:24
nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619
nf_hook include/linux/netfilter.h:280 [inline]
NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:323
NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:325
__netif_receive_skb_one_core net/core/dev.c:6297 [inline]
__netif_receive_skb net/core/dev.c:6410 [inline]
process_backlog+0xa6b/0x18b0 net/core/dev.c:6761
__napi_poll+0xaa/0x330 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0x61d/0xf50 net/core/dev.c:8050
handle_softirqs+0x226/0x860 kernel/softirq.c:645
__do_softirq kernel/softirq.c:679 [inline]
invoke_softirq kernel/softirq.c:519 [inline]
__irq_exit_rcu+0xcb/0x220 kernel/softirq.c:758
irq_exit_rcu+0x9/0x30 kernel/softirq.c:775
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: 5b 87 02 e9 c3 08 03 00 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 e3 31 22 00 fb f4 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffffff8ea07ca0 EFLAGS: 00000246
RAX: 0000000001422d55 RBX: ffffffff819bebe0 RCX: 8000000000000001
RDX: 0000000000000001 RSI: ffffffff8e41727c RDI: ffffffff8c6dad80
RBP: ffffffff8ea07d78 R08: ffff8880b8633a1b R09: 1ffff110170c6743
R10: dffffc0000000000 R11: ffffed10170c6744 R12: 0000000000000000
R13: 1ffffffff1d51e00 R14: 1ffffffff1d40f9c R15: dffffc0000000000
arch_safe_halt arch/x86/kernel/process.c:767 [inline]
default_idle+0x9/0x20 arch/x86/kernel/process.c:768
default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x2e0/0x540 kernel/sched/idle.c:355
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:454
rest_init+0x378/0x3a0 init/main.c:732
start_kernel+0x392/0x3e0 init/main.c:1190
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x137/0x1b0 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x157