Re: [PATCH] LoongArch: KVM: Fix memory leak in kvm_loongarch_env_init() error path

[Huacai Chen]

Hi, Bibo,

What do you think about this?


Huacai

On Mon, Aug 17, 2026 at 7:59 PM Chaithanya Lagisetty
<nagachaithanya9911@xxxxxxxxx> wrote:
>
> kvm_loongarch_env_init() allocates the per-CPU kvm_context (vmcs) and
> kvm_loongarch_ops, and registers the perf callbacks, before registering
> the IPI/EIOINTC/PCH-PIC/DMSINTC KVM devices. If any of those device
> registrations fails, the function returned the error directly without
> freeing vmcs and kvm_loongarch_ops or unregistering the perf callbacks.
> kvm_loongarch_init() propagates the error without calling
> kvm_loongarch_env_exit(), so these resources are leaked.
>
> Unwind the already-acquired resources on the error path, mirroring
> kvm_loongarch_env_exit().
>
> Fixes: c532de5a67a7 ("LoongArch: KVM: Add IPI device support")
> Signed-off-by: Chaithanya Lagisetty <nagachaithanya9911@xxxxxxxxx>
> ---
>  arch/loongarch/kvm/main.c | 19 +++++++++++++++----
>  1 file changed, 15 insertions(+), 4 deletions(-)
>
> diff --git a/arch/loongarch/kvm/main.c b/arch/loongarch/kvm/main.c
> index 3e1005526f4b..685d334cf957 100644
> --- a/arch/loongarch/kvm/main.c
> +++ b/arch/loongarch/kvm/main.c
> @@ -385,22 +385,33 @@ static int kvm_loongarch_env_init(void)
>         /* Register LoongArch IPI interrupt controller interface. */
>         ret = kvm_loongarch_register_ipi_device();
>         if (ret)
> -               return ret;
> +               goto err;
>
>         /* Register LoongArch EIOINTC interrupt controller interface. */
>         ret = kvm_loongarch_register_eiointc_device();
>         if (ret)
> -               return ret;
> +               goto err;
>
>         /* Register LoongArch PCH-PIC interrupt controller interface. */
>         ret = kvm_loongarch_register_pch_pic_device();
>         if (ret)
> -               return ret;
> +               goto err;
>
>         /* Register LoongArch DMSINTC interrupt contrroller interface */
> -       if (cpu_has_msgint)
> +       if (cpu_has_msgint) {
>                 ret = kvm_loongarch_register_dmsintc_device();
> +               if (ret)
> +                       goto err;
> +       }
>
> +       return 0;
> +
> +err:
> +       kvm_unregister_perf_callbacks();
> +       kfree(kvm_loongarch_ops);
> +       kvm_loongarch_ops = NULL;
> +       free_percpu(vmcs);
> +       vmcs = NULL;
>         return ret;
>  }
>
> --
> 2.43.0
>