Re: [PATCH] powerpc/xive: Fix refcount leak in xive_spapr_init

From: "Cédric Le Goater" <clg@kaod.org>
To: Miaoqian Lin <linmq006@gmail.com>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>,
	Nick Child <nick.child@ibm.com>,
	Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
	Ammar Faizi <ammarfaizi2@gmail.com>,
	<linuxppc-dev@lists.ozlabs.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] powerpc/xive: Fix refcount leak in xive_spapr_init
Date: Thu, 12 May 2022 18:14:17 +0200	[thread overview]
Message-ID: <cc8cf48b-8acf-c281-a3b2-5acd49e38dfd@kaod.org> (raw)
In-Reply-To: <20220512090535.33397-1-linmq006@gmail.com>

On 5/12/22 11:05, Miaoqian Lin wrote:
> of_find_compatible_node() returns a node pointer with refcount
> incremented, we should use of_node_put() on it when done.
> Add missing of_node_put() to avoid refcount leak.
> 
> Fixes: eac1e731b59e ("powerpc/xive: guest exploitation of the XIVE interrupt controller")
> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>

Reviewed-by: Cédric Le Goater <clg@kaod.org>

Thanks,

C.

> ---
>   arch/powerpc/sysdev/xive/spapr.c | 7 +++++--
>   1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/powerpc/sysdev/xive/spapr.c b/arch/powerpc/sysdev/xive/spapr.c
> index 29456c255f9f..503f544d28e2 100644
> --- a/arch/powerpc/sysdev/xive/spapr.c
> +++ b/arch/powerpc/sysdev/xive/spapr.c
> @@ -830,12 +830,12 @@ bool __init xive_spapr_init(void)
>   	/* Resource 1 is the OS ring TIMA */
>   	if (of_address_to_resource(np, 1, &r)) {
>   		pr_err("Failed to get thread mgmnt area resource\n");
> -		return false;
> +		goto err_put;
>   	}
>   	tima = ioremap(r.start, resource_size(&r));
>   	if (!tima) {
>   		pr_err("Failed to map thread mgmnt area\n");
> -		return false;
> +		goto err_put;
>   	}
>   
>   	if (!xive_get_max_prio(&max_prio))
> @@ -871,6 +871,7 @@ bool __init xive_spapr_init(void)
>   	if (!xive_core_init(np, &xive_spapr_ops, tima, TM_QW1_OS, max_prio))
>   		goto err_mem_free;
>   
> +	of_node_put(np);
>   	pr_info("Using %dkB queues\n", 1 << (xive_queue_shift - 10));
>   	return true;
>   
> @@ -878,6 +879,8 @@ bool __init xive_spapr_init(void)
>   	xive_irq_bitmap_remove_all();
>   err_unmap:
>   	iounmap(tima);
> +err_put:
> +	of_node_put(np);
>   	return false;
>   }
>