[v2] drm: xlnx: zynqmp_dpsub: Add NULL check in zynqmp_audio_init

[v2] drm: xlnx: zynqmp_dpsub: Add NULL check in zynqmp_audio_init

[Charles Han]

devm_kasprintf() calls can return null pointers on failure.
But some return values were not checked in zynqmp_audio_init().
Add NULL check in zynqmp_audio_init(), to handle kernel NULL
pointer dereference error.

Fixes: 3ec5c1579305 ("drm: xlnx: zynqmp_dpsub: Add DP audio support")
Signed-off-by: Charles Han <hanchunchao@inspur.com>
---
 drivers/gpu/drm/xlnx/zynqmp_dp_audio.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp_audio.c b/drivers/gpu/drm/xlnx/zynqmp_dp_audio.c
index fa5f0ace6084..f07ff4eb3a6d 100644
--- a/drivers/gpu/drm/xlnx/zynqmp_dp_audio.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_dp_audio.c
@@ -323,12 +323,16 @@ int zynqmp_audio_init(struct zynqmp_dpsub *dpsub)
 
 	audio->dai_name = devm_kasprintf(dev, GFP_KERNEL,
 					 "%s-dai", dev_name(dev));
+	if (!audio->dai_name)
+		return -ENOMEM;
 
 	for (unsigned int i = 0; i < ZYNQMP_NUM_PCMS; ++i) {
 		audio->link_names[i] = devm_kasprintf(dev, GFP_KERNEL,
 						      "%s-dp-%u", dev_name(dev), i);
 		audio->pcm_names[i] = devm_kasprintf(dev, GFP_KERNEL,
 						     "%s-pcm-%u", dev_name(dev), i);
+		if (!audio->link_names[i] || !audio->pcm_names[i])
+			return -ENOMEM;
 	}
 
 	audio->base = devm_platform_ioremap_resource_byname(pdev, "aud");
-- 
2.43.0

Re: [v2] drm: xlnx: zynqmp_dpsub: Add NULL checks in zynqmp_audio_init()

[Markus Elfring]

…
> Add NULL check in zynqmp_audio_init(), to handle kernel NULL
> pointer dereference error.

* Can it be more desirable to prevent such issues?

* Would the message subject have been nicer with a key word like “PATCH”
  (besides other refinements)?


…
> ---
>  drivers/gpu/drm/xlnx/zynqmp_dp_audio.c | 4 ++++
…

Will you become more familiar with patch version descriptions?
https://lore.kernel.org/all/?q=%22This+looks+like+a+new+version+of+a+previously+submitted+patch%22
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.14-rc2#n310

Regards,
Markus

答复: [v2] drm: xlnx: zynqmp_dpsub: Add NULL checks in zynqmp_audio_init()

[Charles Han(韩春超)]

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Thank you for your suggestions. I will read these documents carefully.

-----邮件原件-----
发件人: Markus Elfring <Markus.Elfring@web.de> 
发送时间: 2025年2月11日 15:56
收件人: Charles Han(韩春超) <hanchunchao@inspur.com>; dri-devel@lists.freedesktop.org; linux-arm-kernel@lists.infradead.org
抄送: LKML <linux-kernel@vger.kernel.org>; David Airlie <airlied@gmail.com>; Laurent Pinchart <laurent.pinchart@ideasonboard.com>; Maarten Lankhorst <maarten.lankhorst@linux.intel.com>; Maxime Ripard <mripard@kernel.org>; Michal Simek <michal.simek@amd.com>; Simona Vetter <simona@ffwll.ch>; Thomas Zimmermann <tzimmermann@suse.de>; Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>; Vishal Sagar <vishal.sagar@amd.com>
主题: Re: [v2] drm: xlnx: zynqmp_dpsub: Add NULL checks in zynqmp_audio_init()

…
> Add NULL check in zynqmp_audio_init(), to handle kernel NULL pointer 
> dereference error.

* Can it be more desirable to prevent such issues?

* Would the message subject have been nicer with a key word like “PATCH”
  (besides other refinements)?


…
> ---
>  drivers/gpu/drm/xlnx/zynqmp_dp_audio.c | 4 ++++
…

Will you become more familiar with patch version descriptions?
https://lore.kernel.org/all/?q=%22This+looks+like+a+new+version+of+a+previously+submitted+patch%22
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.14-rc2#n310

Regards,
Markus

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