From: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
To: Emil Velikov <emil.l.velikov@gmail.com>
Cc: "Maarten Lankhorst" <maarten.lankhorst@linux.intel.com>,
"Maxime Ripard" <mripard@kernel.org>,
"Thomas Zimmermann" <tzimmermann@suse.de>,
"Dave Airlie" <airlied@linux.ie>,
"Daniel Vetter" <daniel@ffwll.ch>,
"Sumit Semwal" <sumit.semwal@linaro.org>,
"Christian König" <christian.koenig@amd.com>,
"ML dri-devel" <dri-devel@lists.freedesktop.org>,
"Intel Graphics Development" <intel-gfx@lists.freedesktop.org>,
"Linux-Kernel@Vger. Kernel. Org" <linux-kernel@vger.kernel.org>,
linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org,
skhan@linuxfoundation.org,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
linux-kernel-mentees@lists.linuxfoundation.org,
"Daniel Vetter" <daniel.vetter@ffwll.ch>
Subject: Re: [PATCH v5 3/3] drm: protect drm_master pointers in drm_lease.c
Date: Wed, 30 Jun 2021 14:37:23 +0800 [thread overview]
Message-ID: <e2ca777f-f185-688a-5813-0ff2e5025f77@gmail.com> (raw)
In-Reply-To: <CACvgo514T=PZCWwhNsYqCC504SJ+2WivcRtmHhDoKsWMSLFU4A@mail.gmail.com>
On 30/6/21 8:16 am, Emil Velikov wrote:
> Hi Desmond,
>
> Couple of small suggestions, with those the series is:
> Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
>
> On Tue, 29 Jun 2021 at 04:38, Desmond Cheong Zhi Xi
> <desmondcheongzx@gmail.com> wrote:
>
>> @@ -128,13 +137,20 @@ bool drm_lease_held(struct drm_file *file_priv, int id)
>> struct drm_master *master;
>> bool ret;
>>
>> - if (!file_priv || !file_priv->master || !file_priv->master->lessor)
>> + if (!file_priv)
>> return true;
>>
>> - master = file_priv->master;
>> + master = drm_file_get_master(file_priv);
>> + if (master == NULL)
>> + return true;
>> + if (!master->lessor) {
>> + drm_master_put(&master);
>> + return true;
>
> Let's add a "ret = true; goto unlock;" here, so we can have a single
> drm_master_put() in the function.
> Nearly all code paths touched by this patch already follow this approach.
>
>> @@ -154,10 +170,16 @@ uint32_t drm_lease_filter_crtcs(struct drm_file *file_priv, uint32_t crtcs_in)
>> int count_in, count_out;
>> uint32_t crtcs_out = 0;
>>
>> - if (!file_priv || !file_priv->master || !file_priv->master->lessor)
>> + if (!file_priv)
>> return crtcs_in;
>>
>> - master = file_priv->master;
>> + master = drm_file_get_master(file_priv);
>> + if (master == NULL)
>> + return crtcs_in;
>> + if (!master->lessor) {
>> + drm_master_put(&master);
>> + return crtcs_in;
>
> Ditto
>
> Thanks
> Emil
>
Sounds good to me, I'll revise these functions. Thanks for the review
and suggestions, Emil.
Best wishes,
Desmond
prev parent reply other threads:[~2021-06-30 6:37 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-29 3:37 [PATCH v5 0/3] drm: address potential UAF bugs with drm_master ptrs Desmond Cheong Zhi Xi
2021-06-29 3:37 ` [PATCH v5 1/3] drm: avoid circular locks in drm_mode_getconnector Desmond Cheong Zhi Xi
2021-06-29 3:37 ` [PATCH v5 2/3] drm: add a locked version of drm_is_current_master Desmond Cheong Zhi Xi
2021-06-29 3:37 ` [PATCH v5 3/3] drm: protect drm_master pointers in drm_lease.c Desmond Cheong Zhi Xi
2021-06-29 16:07 ` Daniel Vetter
2021-06-30 7:18 ` Desmond Cheong Zhi Xi
2021-06-30 8:02 ` Daniel Vetter
2021-06-30 10:39 ` Desmond Cheong Zhi Xi
2021-06-30 0:16 ` Emil Velikov
2021-06-30 6:37 ` Desmond Cheong Zhi Xi [this message]
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