rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5838/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=27981, q=370 ncpus=2)
task:syz-executor state:R running task stack:20544 pid:5838 tgid:5838 ppid:1 task_flags:0x40054c flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x1b33/0x51f0 kernel/sched/core.c:6767
preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6947
preempt_schedule+0xe4/0xf0 kernel/sched/core.c:6971
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
zap_pte_range mm/memory.c:1761 [inline]
zap_pmd_range mm/memory.c:1823 [inline]
zap_pud_range mm/memory.c:1852 [inline]
zap_p4d_range mm/memory.c:1873 [inline]
unmap_page_range+0x39c5/0x44d0 mm/memory.c:1894
unmap_vmas+0x3ce/0x5f0 mm/memory.c:1984
exit_mmap+0x2bc/0xde0 mm/mmap.c:1284
__mmput+0x115/0x410 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+0x98/0x840 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_syscall_64+0x100/0x230 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9663d833d7
RSP: 002b:00007fff8be55870 EFLAGS: 00000293 ORIG_RAX: 000000000000003d
RAX: fffffffffffffe00 RBX: 00000000000001f4 RCX: 00007f9663d833d7
RDX: 0000000040000000 RSI: 00007fff8be558dc RDI: 00000000ffffffff
RBP: 00007fff8be558dc R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 000000000000009b
R13: 0000555568631570 R14: 0000000000062002 R15: 00007fff8be55930
rcu: rcu_preempt kthread starved for 4192 jiffies! g27981 f0x0 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:26744 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x1b33/0x51f0 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-rc1-syzkaller-00308-gecd5d67ad602 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:55 [inline]
RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:393 [inline]
RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:403 [inline]
RIP: 0010:unwind_next_frame+0x991/0x23b0 arch/x86/kernel/unwind_orc.c:585
Code: 03 00 00 83 fe 02 0f 85 b1 04 00 00 48 89 ac 24 88 00 00 00 49 8d 6c 24 08 48 89 e8 48 c1 e8 03 48 89 44 24 58 42 80 3c 28 00 <74> 08 48 89 ef e8 a5 e6 bc 00 48 89 6c 24 60 48 89 5c 24 68 4c 89
RSP: 0018:ffffc90000006408 EFLAGS: 00000246
RAX: 1ffff92000000ca9 RBX: 1ffffffff21d2b29 RCX: ffffffff9071b564
RDX: ffffffff90e95944 RSI: 0000000000000002 RDI: ffffffff8ca0e000
RBP: ffffc90000006548 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffc90000006540
R13: dffffc0000000000 R14: ffffc90000006578 R15: ffffffff90e95948
FS: 0000000000000000(0000) GS:ffff888124fc9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd8192bc7c CR3: 0000000062498000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__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 mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:319 [inline]
__kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4151 [inline]
slab_alloc_node mm/slub.c:4200 [inline]
kmem_cache_alloc_noprof+0x1e1/0x390 mm/slub.c:4207
skb_clone+0x20c/0x390 net/core/skbuff.c:2056
netem_enqueue+0x1267/0x3ad0 net/sched/sch_netem.c:490
dev_qdisc_enqueue+0x4b/0x290 net/core/dev.c:3982
__dev_xmit_skb net/core/dev.c:4078 [inline]
__dev_queue_xmit+0xf13/0x3f60 net/core/dev.c:4593
dev_queue_xmit include/linux/netdevice.h:3350 [inline]
neigh_hh_output include/net/neighbour.h:523 [inline]
neigh_output include/net/neighbour.h:537 [inline]
ip_finish_output2+0xcd2/0x12e0 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:5885 [inline]
__netif_receive_skb+0x2c9/0x670 net/core/dev.c:5998
process_backlog+0x664/0x15c0 net/core/dev.c:6350
__napi_poll+0xcb/0x480 net/core/dev.c:7322
napi_poll net/core/dev.c:7386 [inline]
net_rx_action+0x89d/0x1240 net/core/dev.c:7508
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 0f 1f 00 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 d3 70 1f 00 f3 0f 1e fa fb f4 cc cc cc cc 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8ea07d60 EFLAGS: 000002c6
RAX: dc1f37c0fd3b6300 RBX: ffffffff81979e0e RCX: ffffffff8c28c95c
RDX: 0000000000000001 RSI: ffffffff8e68835e RDI: ffffffff8ca0e060
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