2018-06-29 17:39:55

by Nicholas Mc Guire

Subject: [PATCH] ALSA: snd-aoa: add of_node_put() in error path

Both calls to of_find_node_by_name() and of_get_next_child() return a
node pointer with refcount incremented thus it must be explicidly
decremented here after the last usage. As we are assured to have a
refcounted np either from the initial
of_find_node_by_name(NULL, name); or from the of_get_next_child(gpio, np)
in the while loop if we reached the error code path below, an
x of_node_put(np) is needed.

Signed-off-by: Nicholas Mc Guire <[email protected]>
Fixes: commit f3d9478b2ce4 ("[ALSA] snd-aoa: add snd-aoa")
---

Problem located by an experimental coccinelle script

Patch was compiletested with: ppc64_defconfig (implies CONFIG_SND_AOA=m)

Patch is against 4.18-rc2 (localversion-next is next-20180629)

sound/aoa/core/gpio-feature.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/sound/aoa/core/gpio-feature.c b/sound/aoa/core/gpio-feature.c
index 7196008..6555742 100644
--- a/sound/aoa/core/gpio-feature.c
+++ b/sound/aoa/core/gpio-feature.c
@@ -88,8 +88,10 @@ static struct device_node *get_gpio(char *name,
}

reg = of_get_property(np, "reg", NULL);
- if (!reg)
+ if (!reg) {
+ of_node_put(np);
return NULL;
+ }

*gpioptr = *reg;

--
2.1.4

2018-06-29 20:21:22

by Takashi Iwai

Subject: Re: [PATCH] ALSA: snd-aoa: add of_node_put() in error path

On Fri, 29 Jun 2018 19:07:42 +0200,
Nicholas Mc Guire wrote:
>
> Both calls to of_find_node_by_name() and of_get_next_child() return a
> node pointer with refcount incremented thus it must be explicidly
> decremented here after the last usage. As we are assured to have a
> refcounted np either from the initial
> of_find_node_by_name(NULL, name); or from the of_get_next_child(gpio, np)
> in the while loop if we reached the error code path below, an
> x of_node_put(np) is needed.
>
> Signed-off-by: Nicholas Mc Guire <[email protected]>
> Fixes: commit f3d9478b2ce4 ("[ALSA] snd-aoa: add snd-aoa")
> ---
>
> Problem located by an experimental coccinelle script
>
> Patch was compiletested with: ppc64_defconfig (implies CONFIG_SND_AOA=m)
>
> Patch is against 4.18-rc2 (localversion-next is next-20180629)

Applied, thanks.


Takashi