rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P21231/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=167629, q=1105876 ncpus=2)
task:syz.3.4731 state:R running task stack:26800 pid:21231 tgid:21230 ppid:15599 task_flags:0x40044c flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5533 [inline]
__schedule+0x17db/0x58f0 kernel/sched/core.c:7284
preempt_schedule_notrace+0x56/0x90 kernel/sched/core.c:7556
preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13
rcu_is_watching+0x81/0xb0 kernel/rcu/tree.c:754
trace_lock_acquire include/trace/events/lock.h:23 [inline]
lock_acquire+0x58/0x350 kernel/locking/lockdep.c:5905
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]
is_module_text_address+0x39/0x1e0 kernel/module/main.c:3934
kernel_text_address+0x94/0xe0 kernel/extable.c:119
__kernel_text_address+0xd/0x30 kernel/extable.c:79
unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:385
arch_stack_walk+0xfb/0x150 arch/x86/kernel/stacktrace.c:26
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
__call_rcu_common kernel/rcu/tree.c:3181 [inline]
call_rcu+0xee/0x8b0 kernel/rcu/tree.c:3301
slab_free_hook mm/slub.c:2712 [inline]
slab_free mm/slub.c:6508 [inline]
kmem_cache_free+0x471/0x650 mm/slub.c:6635
tear_down_vmas+0x31f/0x530 mm/mmap.c:1277
exit_mmap+0x4ca/0x9f0 mm/mmap.c:1335
__mmput+0x118/0x420 kernel/fork.c:1193
exit_mm+0x221/0x2d0 kernel/exit.c:618
do_exit+0x6cd/0x2360 kernel/exit.c:1000
do_group_exit+0x22d/0x2f0 kernel/exit.c:1155
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: 0033:0x7f8411d9e159
RSP: 002b:00007f8412d0e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: 000000000000000b RBX: 00007f8412025fa0 RCX: 00007f8411d9e159
RDX: 0000000000000318 RSI: 00002000000bd000 RDI: 0000000000000011
RBP: 00007f8411e3506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8412026038 R14: 00007f8412025fa0 R15: 00007f841214fa48
rcu: rcu_preempt kthread starved for 2538 jiffies! g167629 f0x2 RCU_GP_WAIT_FQS(5) ->state=R ->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: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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:lock_release+0x12/0x3c0 kernel/locking/lockdep.c:5951
Code: 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 30 <49> 89 f5 49 89 fe 65 48 8b 05 88 f7 f1 11 48 89 44 24 28 0f 1f 44
RSP: 0018:ffffc90000a17e98 EFLAGS: 00000282
RAX: 0000000000000001 RBX: ffffc90000a17fb8 RCX: 8000000000000102
RDX: ffffffff9112fe01 RSI: ffffffff8177f1df RDI: ffffffff8ed5c920
RBP: 1ffffffff2225f01 R08: ffffc90000a18ff8 R09: 0000000000000000
R10: ffffc90000a17ff8 R11: fffff52000143001 R12: ffffc90000a11000
R13: ffffffff8177f1df R14: ffffc90000a17fa8 R15: ffffc90000a18ff8
FS: 0000000000000000(0000) GS:ffff888124dca000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055556ce0f4e8 CR3: 00000000796cc000 CR4: 00000000003526f0
Call Trace:
rcu_lock_release include/linux/rcupdate.h:319 [inline]
rcu_read_unlock include/linux/rcupdate.h:880 [inline]
class_rcu_destructor include/linux/rcupdate.h:1216 [inline]
unwind_next_frame+0x1baa/0x2550 arch/x86/kernel/unwind_orc.c:709
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
__call_rcu_common kernel/rcu/tree.c:3181 [inline]
call_rcu+0xee/0x8b0 kernel/rcu/tree.c:3301
refdst_drop include/net/dst.h:272 [inline]
skb_dst_drop include/net/dst.h:284 [inline]
skb_release_head_state+0x71/0x370 net/core/skbuff.c:1171
skb_release_all net/core/skbuff.c:1195 [inline]
__kfree_skb+0x24/0x210 net/core/skbuff.c:1211
nft_synproxy_eval_v4+0x36a/0x4e0 net/netfilter/nft_synproxy.c:-1
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:6265 [inline]
__netif_receive_skb net/core/dev.c:6378 [inline]
process_backlog+0xa6b/0x18b0 net/core/dev.c:6729
__napi_poll+0xaa/0x330 net/core/dev.c:7798
napi_poll net/core/dev.c:7861 [inline]
net_rx_action+0x61d/0xf50 net/core/dev.c:8018
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: 2c 88 02 e9 83 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 11 23 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:ffffc900001a7e40 EFLAGS: 00000242
RAX: 0000000000ef46cb RBX: ffffffff819bbcb0 RCX: 8000000000000001
RDX: 0000000000000001 RSI: ffffffff8e415a94 RDI: ffffffff8c6dac80
RBP: ffffc900001a7f10 R08: ffff8880b8733a1b R09: 1ffff110170e6743
R10: dffffc0000000000 R11: ffffed10170e6744 R12: 0000000000000000
R13: 1ffff11003cd1bb8 R14: 1ffff92000034fd0 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
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x157