[v5.15] INFO: rcu detected stall in wg_packet_handshake_send_worker

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 9465fef4ae35 Linux 5.15.153
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=109038f3180000
kernel config: https://syzkaller.appspot.com/x/.config?x=176c746ee3348b33
dashboard link: https://syzkaller.appspot.com/bug?extid=a8777022af5dd4279459
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/2962c02652ce/disk-9465fef4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d0f5a1ce082d/vmlinux-9465fef4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/86b5b1eea636/bzImage-9465fef4.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a87770...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=de7/1/0x4000000000000000 softirq=51494/51496 fqs=1
(detected by 1, t=10505 jiffies, g=78145, q=117)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 2583 Comm: kworker/u4:4 Not tainted 5.15.153-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: wg-kex-wg2 wg_packet_handshake_send_worker
RIP: 0010:preempt_count_add+0x58/0x180 kernel/sched/core.c:5493
Code: 0f 00 75 07 65 8b 05 1f 2f ab 7e 65 01 1d 18 2f ab 7e 48 c7 c0 c0 7f 3c 91 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 d9 00 00 00 <83> 3d f1 3e e5 0f 00 75 11 65 8b 05 f0 2e ab 7e 0f b6 c0 3d f5 00
RSP: 0018:ffffc90000007ca0 EFLAGS: 00000097
RAX: 0000000000000004 RBX: 0000000000000001 RCX: ffffffff913c7f03
RDX: 0000000080010802 RSI: ffffffff8ad88fa0 RDI: 0000000000000001
RBP: ffffc90000007d50 R08: ffffffff816f437e R09: fffffbfff1bc72a6
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8880b9a2a200
R13: 1ffff92000000f98 R14: ffffc90000007ce0 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fca001dc988 CR3: 00000000610a4000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000c40a DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
<NMI>
</NMI>
<IRQ>
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:127 [inline]
_raw_spin_lock_irq+0xb3/0x110 kernel/locking/spinlock.c:170
__run_hrtimer kernel/time/hrtimer.c:1690 [inline]
__hrtimer_run_queues+0x662/0xcf0 kernel/time/hrtimer.c:1750
hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline]
__sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102
sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xd4/0x130 kernel/locking/spinlock.c:194
Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 a2 82 a4 f7 f6 44 24 21 02 75 4e 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> d7 cb 31 f7 65 8b 05 a8 f9 dc 75 85 c0 74 3f 48 c7 04 24 0e 36
RSP: 0018:ffffc9000b9def80 EFLAGS: 00000206
RAX: fa661bfb528b3800 RBX: 1ffff9200173bdf4 RCX: ffffffff8162f8e8
RDX: dffffc0000000000 RSI: ffffffff8a8b1500 RDI: 0000000000000001
RBP: ffffc9000b9df020 R08: dffffc0000000000 R09: fffffbfff1f7a037
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff9200173bdf0 R14: ffffc9000b9defa0 R15: 0000000000000246
stack_depot_save+0x3db/0x440 lib/stackdepot.c:331
kasan_save_stack mm/kasan/common.c:40 [inline]
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
__kasan_slab_alloc+0xa5/0xc0 mm/kasan/common.c:467
kasan_slab_alloc include/linux/kasan.h:254 [inline]
slab_post_alloc_hook+0x53/0x380 mm/slab.h:519
slab_alloc_node mm/slub.c:3220 [inline]
slab_alloc mm/slub.c:3228 [inline]
kmem_cache_alloc+0xf3/0x280 mm/slub.c:3233
skb_clone+0x1bb/0x350 net/core/skbuff.c:1523
dev_queue_xmit_nit+0x2d6/0xae0 net/core/dev.c:2310
xmit_one net/core/dev.c:3612 [inline]
dev_hard_start_xmit+0x137/0x7a0 net/core/dev.c:3633
__dev_queue_xmit+0x1cee/0x3230 net/core/dev.c:4248
neigh_hh_output include/net/neighbour.h:493 [inline]
neigh_output include/net/neighbour.h:507 [inline]
ip6_finish_output2+0xead/0x14f0 net/ipv6/ip6_output.c:126
ip6tunnel_xmit include/net/ip6_tunnel.h:160 [inline]
udp_tunnel6_xmit_skb+0x538/0x970 net/ipv6/ip6_udp_tunnel.c:109
send6+0x6a7/0xad0 drivers/net/wireguard/socket.c:152
wg_socket_send_skb_to_peer+0x111/0x1d0 drivers/net/wireguard/socket.c:178
wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:40 [inline]
wg_packet_handshake_send_worker+0x1d9/0x310 drivers/net/wireguard/send.c:51
process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
kthread+0x3f6/0x4f0 kernel/kthread.c:319
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
</TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g78145 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=32212
rcu: rcu_preempt kthread starved for 10500 jiffies! g78145 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26712 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
schedule+0x11b/0x1f0 kernel/sched/core.c:6459
schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1884
rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972
rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145
kthread+0x3f6/0x4f0 kernel/kthread.c:319
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
</TASK>
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 1
CPU: 1 PID: 3722 Comm: kworker/1:19 Not tainted 5.15.153-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: events bpf_prog_free_deferred
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
rcu_check_gp_kthread_starvation+0x1d2/0x240 kernel/rcu/tree_stall.h:487
print_other_cpu_stall+0x137a/0x14d0 kernel/rcu/tree_stall.h:592
check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
rcu_pending kernel/rcu/tree.c:3932 [inline]
rcu_sched_clock_irq+0xa38/0x1150 kernel/rcu/tree.c:2619
update_process_times+0x196/0x200 kernel/time/timer.c:1788
tick_sched_handle kernel/time/tick-sched.c:254 [inline]
tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473
__run_hrtimer kernel/time/hrtimer.c:1686 [inline]
__hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1750
hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline]
__sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102
sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline]
RIP: 0010:smp_call_function_many_cond+0xaa1/0xd90 kernel/smp.c:969
Code: 44 89 fe 83 e6 01 31 ff e8 1c cf 0b 00 41 83 e7 01 75 07 e8 b1 cb 0b 00 eb 41 f3 90 48 b8 00 00 00 00 00 fc ff df 0f b6 04 03 <84> c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 8c cb 0b 00 eb db 44
RSP: 0018:ffffc90004ef78a0 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 1ffff11017348541 RCX: ffff88801d768000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90004ef79e0 R08: ffffffff81746df4 R09: fffffbfff1f7a01a
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: ffff8880b9a42a08 R14: ffff8880b9b3b380 R15: 0000000000000001
on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1135
__purge_vmap_area_lazy+0x294/0x1740 mm/vmalloc.c:1683
_vm_unmap_aliases+0x453/0x4e0 mm/vmalloc.c:2107
vm_remove_mappings mm/vmalloc.c:2584 [inline]
__vunmap+0x72e/0xa20 mm/vmalloc.c:2611
bpf_jit_binary_free kernel/bpf/core.c:914 [inline]
bpf_jit_free+0x92/0x180 kernel/bpf/core.c:927
process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
kthread+0x3f6/0x4f0 kernel/kthread.c:319
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
</TASK>


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