Re: [PATCH v2] arm/xen: Fix some refcount leaks

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Wed, 20 Apr 2022, Miaoqian Lin wrote:
> The of_find_compatible_node() function returns a node pointer with
> refcount incremented, We should use of_node_put() on it when done
> Add the missing of_node_put() to release the refcount.
> 
> Fixes: 9b08aaa3199a ("ARM: XEN: Move xen_early_init() before efi_init()")
> Fixes: b2371587fe0c ("arm/xen: Read extended regions from DT and init Xen 
> resource")
> Signed-off-by: Miaoqian Lin <linmq006@xxxxxxxxx>

Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>

Juergen,  Boris,
I applied the patch to for-linus-5.18


> ---
> changes in v2:
> - call of_node_put in non-error path in xen_dt_guest_init
> - fix same refcount leak error in arch_xen_unpopulated_init
> ---
>  arch/arm/xen/enlighten.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> index ec5b082f3de6..07eb69f9e7df 100644
> --- a/arch/arm/xen/enlighten.c
> +++ b/arch/arm/xen/enlighten.c
> @@ -337,12 +337,15 @@ int __init arch_xen_unpopulated_init(struct resource 
> **res)
>  
>       if (!nr_reg) {
>               pr_err("No extended regions are found\n");
> +             of_node_put(np);
>               return -EINVAL;
>       }
>  
>       regs = kcalloc(nr_reg, sizeof(*regs), GFP_KERNEL);
> -     if (!regs)
> +     if (!regs) {
> +             of_node_put(np);
>               return -ENOMEM;
> +     }
>  
>       /*
>        * Create resource from extended regions provided by the hypervisor to 
> be
> @@ -403,8 +406,8 @@ int __init arch_xen_unpopulated_init(struct resource 
> **res)
>       *res = &xen_resource;
>  
>  err:
> +     of_node_put(np);
>       kfree(regs);
> -
>       return rc;
>  }
>  #endif
> @@ -424,8 +427,10 @@ static void __init xen_dt_guest_init(void)
>  
>       if (of_address_to_resource(xen_node, GRANT_TABLE_INDEX, &res)) {
>               pr_err("Xen grant table region is not found\n");
> +             of_node_put(xen_node);
>               return;
>       }
> +     of_node_put(xen_node);
>       xen_grant_frames = res.start;
>  }
>  
> -- 
> 2.17.1
>