rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P15805/1:b..l P12297/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=97829, q=986854 ncpus=2)
task:syz.5.1863 state:R running task stack:27016 pid:12297 tgid:12297 ppid:10361 task_flags:0x40044c flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7145
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7169
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+0x3f/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
zap_pte_range mm/memory.c:1884 [inline]
zap_pmd_range mm/memory.c:1946 [inline]
zap_pud_range mm/memory.c:1975 [inline]
zap_p4d_range mm/memory.c:1996 [inline]
unmap_page_range+0x3a7f/0x4370 mm/memory.c:2017
unmap_single_vma mm/memory.c:2060 [inline]
unmap_vmas+0x399/0x580 mm/memory.c:2104
exit_mmap+0x248/0xb50 mm/mmap.c:1280
__mmput+0x118/0x420 kernel/fork.c:1133
exit_mm+0x1da/0x2c0 kernel/exit.c:582
do_exit+0x648/0x2300 kernel/exit.c:949
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
get_signal+0x1286/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x130 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4c671c14a5
RSP: 002b:00007f4c6808bf80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007f4c673c5fa0 RCX: 00007f4c671c14a5
RDX: 00007f4c6808bfc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f4c67211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 00007f4c673c6038 R14: 00007f4c673c5fa0 R15: 00007ffef309eba8
task:syz.5.2615 state:R running task stack:27016 pid:15805 tgid:15805 ppid:10361 task_flags:0x40044c flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288
irqentry_exit+0x6f/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__read_once_word_nocheck+0x3/0x10 include/asm-generic/rwonce.h:67
Code: b0 00 48 ba 00 00 00 00 00 fc ff df e9 88 fc ff ff 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 48 8b 07 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc900041472d0 EFLAGS: 00000202
RAX: ffffffff81000130 RBX: ffffc90004147f40 RCX: 1ffff92000828e01
RDX: ffffffff911f05a8 RSI: 0000000000000002 RDI: ffffc90004147f40
RBP: 1ffff92000828e76 R08: 0000000000000001 R09: 0000000000000000
R10: ffffc900041473f8 R11: ffffffff81ad6180 R12: ffffc90004148000
R13: 1ffff92000828e77 R14: ffffc900041473a8 R15: ffffc90004140000
deref_stack_reg arch/x86/kernel/unwind_orc.c:406 [inline]
unwind_next_frame+0xc3c/0x2390 arch/x86/kernel/unwind_orc.c:585
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
poison_kmalloc_redzone mm/kasan/common.c:397 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414
kasan_kmalloc include/linux/kasan.h:260 [inline]
__kmalloc_cache_noprof+0x21c/0x3a0 mm/slub.c:4396
kmalloc_noprof include/linux/slab.h:909 [inline]
slab_free_hook mm/slub.c:2369 [inline]
slab_free mm/slub.c:4680 [inline]
kmem_cache_free+0x166/0x400 mm/slub.c:4782
exit_mmap+0x53f/0xb50 mm/mmap.c:1305
__mmput+0x118/0x420 kernel/fork.c:1133
exit_mm+0x1da/0x2c0 kernel/exit.c:582
do_exit+0x648/0x2300 kernel/exit.c:949
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
get_signal+0x1286/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x130 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4c671c14a5
RSP: 002b:00007f4c6808bf80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007f4c673c5fa0 RCX: 00007f4c671c14a5
RDX: 00007f4c6808bfc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f4c67211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 00007f4c673c6038 R14: 00007f4c673c5fa0 R15: 00007ffef309eba8
rcu: rcu_preempt kthread starved for 253 jiffies! g97829 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:27464 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:148
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: 18758 Comm: kworker/u8:9 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: wg-kex-wg1 wg_packet_handshake_send_worker
RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216
Code: 8b 3d c4 56 2b 0c 48 89 de 5b e9 33 e2 58 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 08 c0 e5 92 65 8b 15 48 f1 24 11 81 e2 00 01 ff 00
RSP: 0018:ffffc90000007858 EFLAGS: 00000297
RAX: ffffffff89f74c25 RBX: 0000000000000000 RCX: 0000000000000100
RDX: ffff888029b1da00 RSI: 0000000000000000 RDI: 0000000000000001
RBP: ffffc90000007970 R08: ffff888029b1da00 R09: 0000000000000004
R10: 0000000000000003 R11: 0000000000000100 R12: 1ffff92000000f14
R13: ffffc900000078c0 R14: 0000000000000000 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8881257c4000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd100a4da8 CR3: 00000000683e0000 CR4: 00000000003526f0
Call Trace:
NF_HOOK+0x315/0x3a0 include/linux/netfilter.h:317
NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318
__netif_receive_skb_one_core net/core/dev.c:5991 [inline]
__netif_receive_skb+0x143/0x380 net/core/dev.c:6104
process_backlog+0x60e/0x14f0 net/core/dev.c:6456
__napi_poll+0xc4/0x360 net/core/dev.c:7506
napi_poll net/core/dev.c:7569 [inline]
net_rx_action+0x707/0xe30 net/core/dev.c:7696
handle_softirqs+0x283/0x870 kernel/softirq.c:579
do_softirq+0xec/0x180 kernel/softirq.c:480
__local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:407
wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:42 [inline]
wg_packet_handshake_send_worker+0x1e3/0x320 drivers/net/wireguard/send.c:51
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245