rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7193/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=24885, q=943901 ncpus=2)
task:syz.0.366 state:R running task stack:26088 pid:7193 tgid:7193 ppid:5861 task_flags:0x40044c flags:0x20004004
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x1b88/0x5240 kernel/sched/core.c:6767
preempt_schedule_irq+0xfe/0x1c0 kernel/sched/core.c:7090
irqentry_exit+0x5e/0x90 kernel/entry/common.c:354
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:trace_lock_acquire include/trace/events/lock.h:24 [inline]
RIP: 0010:lock_acquire+0x57/0x2f0 kernel/locking/lockdep.c:5829
Code: 11 65 48 8b 45 00 48 89 44 24 38 0f 1f 44 00 00 65 8b 05 d0 f8 c9 11 83 f8 08 0f 83 b4 01 00 00 89 c0 48 0f a3 05 f9 7d c1 0e <73> 16 e8 52 c6 09 00 84 c0 75 0d f6 05 5a 64 ab 0e 01 0f 84 9b 01
RSP: 0018:ffffc90002e3ee48 EFLAGS: 00000297
RAX: 0000000000000001 RBX: ffffffff8ed3df20 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8ed3df20
RBP: ffffffff93686020 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90002e3f000 R11: fffff520005c7e0c R12: 0000000000000000
R13: 0000000000000002 R14: ffffffff816dc508 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xd5/0x23b0 arch/x86/kernel/unwind_orc.c:479
__unwind_start+0x59a/0x740 arch/x86/kernel/unwind_orc.c:758
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe7/0x150 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x11a/0x1d0 kernel/stacktrace.c:122
kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
kasan_record_aux_stack+0xbf/0xd0 mm/kasan/generic.c:548
__call_rcu_common kernel/rcu/tree.c:3082 [inline]
call_rcu+0x172/0xad0 kernel/rcu/tree.c:3202
slab_free_hook mm/slub.c:2362 [inline]
slab_free mm/slub.c:4656 [inline]
kmem_cache_free+0x312/0x410 mm/slub.c:4758
anon_vma_free mm/rmap.c:137 [inline]
__put_anon_vma+0x128/0x2d0 mm/rmap.c:2756
put_anon_vma include/linux/rmap.h:117 [inline]
unlink_anon_vmas+0x492/0x5f0 mm/rmap.c:444
free_pgtables+0x44e/0x6f0 mm/memory.c:391
exit_mmap+0x5a9/0xde0 mm/mmap.c:1295
__mmput+0x115/0x420 kernel/fork.c:1379
exit_mm+0x221/0x310 kernel/exit.c:589
do_exit+0x994/0x27f0 kernel/exit.c:940
do_group_exit+0x207/0x2c0 kernel/exit.c:1102
get_signal+0x1696/0x1730 kernel/signal.c:3034
arch_do_signal_or_restart+0x98/0x810 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218
__do_fast_syscall_32+0xc1/0x110 arch/x86/entry/syscall_32.c:309
do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf70fd539
RSP: 002b:00000000f50ed460 EFLAGS: 00000206 ORIG_RAX: 000000000000010b
RAX: 00000000fa6cb3d1 RBX: 0000000051766018 RCX: 00000000107b9d14
RDX: 00000000bb4f02b4 RSI: 000000009b8908dc RDI: 00000000f29d588f
RBP: 00000000a8d7b5db R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 2777 jiffies! g24885 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:26440 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x1b88/0x5240 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x163/0x360 kernel/sched/core.c:6860
schedule_timeout+0x15b/0x2b0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x2e1/0x1340 kernel/rcu/tree.c:2046
rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2248
kthread+0x7b7/0x940 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.15.0-rc3-syzkaller-00008-ga33b5a08cbbd #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:127 [inline]
RIP: 0010:lock_release+0xab/0x3e0 kernel/locking/lockdep.c:5883
Code: 60 68 93 41 83 bd ec 0a 00 00 00 0f 85 ae 01 00 00 48 c7 c0 d0 f6 2b 94 49 39 07 0f 84 9e 01 00 00 48 c7 44 24 20 00 00 00 00 <9c> 8f 44 24 20 4c 8b 74 24 20 fa 48 c7 c7 f8 56 50 8e e8 0e 47 91
RSP: 0018:ffffc90000006dd8 EFLAGS: 00000006
RAX: ffffffff942bf6d0 RBX: ffffffff93686020 RCX: c36b2f6eb5274000
RDX: 0000000000000000 RSI: ffffffff8ca1b660 RDI: ffffffff8ca1b620
RBP: ffffffff8a437e8a R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888027a251e0
R13: ffffffff8ea96580 R14: 0000000000000200 R15: ffff888027a251f0
FS: 0000000000000000(0000) GS:ffff888124f9a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000800fa018 CR3: 0000000056bb0000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
seqcount_lockdep_reader_access include/linux/seqlock.h:73 [inline]
read_seqbegin include/linux/seqlock.h:836 [inline]
neigh_hh_output include/net/neighbour.h:493 [inline]
neigh_output include/net/neighbour.h:537 [inline]
ip_finish_output2+0x787/0x12e0 net/ipv4/ip_output.c:235
synproxy_send_client_synack+0x8ea/0xf70 net/netfilter/nf_synproxy_core.c:484
nft_synproxy_eval_v4+0x3cc/0x610 net/netfilter/nft_synproxy.c:59
nft_synproxy_do_eval+0x36a/0xa90 net/netfilter/nft_synproxy.c:141
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x4b2/0x1db0 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0x41f/0x6b0 net/netfilter/nft_chain_filter.c:161
nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
nf_hook_slow+0xc8/0x220 net/netfilter/core.c:626
nf_hook include/linux/netfilter.h:269 [inline]
NF_HOOK+0x29b/0x450 include/linux/netfilter.h:312
NF_HOOK+0x3a0/0x450 include/linux/netfilter.h:314
__netif_receive_skb_one_core net/core/dev.c:5887 [inline]
__netif_receive_skb+0x2c9/0x670 net/core/dev.c:6000
process_backlog+0x664/0x15c0 net/core/dev.c:6352
__napi_poll+0xcb/0x480 net/core/dev.c:7324
napi_poll net/core/dev.c:7388 [inline]
net_rx_action+0x89d/0x1240 net/core/dev.c:7510
handle_softirqs+0x2d6/0x9b0 kernel/softirq.c:579
__do_softirq kernel/softirq.c:613 [inline]
invoke_softirq kernel/softirq.c:453 [inline]
__irq_exit_rcu+0xfb/0x220 kernel/softirq.c:680
irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
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 53 7e 18 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:ffffffff8ea07d60 EFLAGS: 000002c6
RAX: c36b2f6eb5274000 RBX: ffffffff8197272e RCX: ffffffff8c2fb89c
RDX: 0000000000000001 RSI: ffffffff8e6497f7 RDI: ffffffff8ca1b680
RBP: ffffffff8ea07eb8 R08: ffff8880b8632b5b R09: 1ffff110170c656b
R10: dffffc0000000000 R11: ffffed10170c656c R12: 1ffffffff1d40fc6
R13: 1ffffffff1d52cb0 R14: 0000000000000000 R15: dffffc0000000000
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+0x22e/0x5d0 kernel/sched/idle.c:325
cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:423
rest_init+0x2dc/0x300 init/main.c:743
start_kernel+0x484/0x510 init/main.c:1099
x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:513
x86_64_start_kernel+0x66/0x70 arch/x86/kernel/head64.c:494
common_startup_64+0x13e/0x147