Re: [PATCH 2/2] drm: fix a memleak on mutex failure path

Jani Nikula
2015-04-27T08:56:00Z

On Sun, 26 Apr 2015, green@linuxhacker.ru wrote:
> From: Oleg Drokin <green@linuxhacker.ru>
>
> Need to free just allocated ctx allocation if we cannot
> get our config mutex.
>
> This one has been flagged by kbuild bot all the way back in August,
> but somehow nobody picked it up:
> https://lists.01.org/pipermail/kbuild/2014-August/001691.html
>
> Found with smatch.
>
> Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
> CC: Daniel Vetter <daniel.vetter@ffwll.ch>

The function has another leaking failure path, would be nice to have
that fixed too. Maybe with a common out label.

BR,
Jani.

> ---
> drivers/gpu/drm/drm_modeset_lock.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_modeset_lock.c b/drivers/gpu/drm/drm_modeset_lock.c
> index 51cc47d..1e8c52f 100644
> --- a/drivers/gpu/drm/drm_modeset_lock.c
> +++ b/drivers/gpu/drm/drm_modeset_lock.c
> @@ -80,8 +80,10 @@ int __drm_modeset_lock_all(struct drm_device *dev,
> return -ENOMEM;
>
> if (trylock) {
> - if (!mutex_trylock(&config->mutex))
> + if (!mutex_trylock(&config->mutex)) {
> + kfree(ctx);
> return -EBUSY;
> + }
> } else {
> mutex_lock(&config->mutex);
> }
> --
> 2.1.0
>
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--
Jani Nikula, Intel Open Source Technology Center