devm_kasprintf() returns NULL when memory allocation fails. Currently,
wled_configure() does not check for this case, which results in a NULL
pointer dereference.

Add NULL check after devm_kasprintf() to prevent this issue.

Fixes: f86b77583d88 ("backlight: pm8941: Convert to using %pOFn instead of device_node.name")
Signed-off-by: Henry Martin <bsdhenrymartin@gmail.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Daniel Thompson (RISCstar) <danielt@kernel.org>
---
V3 -> V4: No functional changes, just correcting the version number
V2 -> V3: Correct commit meessage and confirm this patch has considered
resource cleanup to avoid any subsequent issues, ensuring that errors
are handled properly and no resources are left in an inconsistent
state.
V1 -> V2: Fix commit message to use imperative mood and wrap lines to 75
characters.

 drivers/video/backlight/qcom-wled.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
index 9afe701b2a1b..a63bb42c8f8b 100644
--- a/drivers/video/backlight/qcom-wled.c
+++ b/drivers/video/backlight/qcom-wled.c
@@ -1406,9 +1406,11 @@ static int wled_configure(struct wled *wled)
 	wled->ctrl_addr = be32_to_cpu(*prop_addr);
 
 	rc = of_property_read_string(dev->of_node, "label", &wled->name);
-	if (rc)
+	if (rc) {
 		wled->name = devm_kasprintf(dev, GFP_KERNEL, "%pOFn", dev->of_node);
-
+		if (!wled->name)
+			return -ENOMEM;
+	}
 	switch (wled->version) {
 	case 3:
 		u32_opts = wled3_opts;
-- 
2.34.1

On Tue, 01 Apr 2025 17:16:47 +0800, Henry Martin wrote:
> devm_kasprintf() returns NULL when memory allocation fails. Currently,
> wled_configure() does not check for this case, which results in a NULL
> pointer dereference.
> 
> Add NULL check after devm_kasprintf() to prevent this issue.
> 
> 
> [...]

Applied, thanks!

[1/1] backlight: pm8941: Add NULL check in wled_configure()
      commit: b0fdeb96ead46de57a6226bc3a3ac7f9b50c0ace

--
Lee Jones [李琼斯]

On Fri, 04 Apr 2025, Lee Jones wrote:

> On Tue, 01 Apr 2025 17:16:47 +0800, Henry Martin wrote:
> > devm_kasprintf() returns NULL when memory allocation fails. Currently,
> > wled_configure() does not check for this case, which results in a NULL
> > pointer dereference.
> > 
> > Add NULL check after devm_kasprintf() to prevent this issue.
> > 
> > 
> > [...]
> 
> Applied, thanks!
> 
> [1/1] backlight: pm8941: Add NULL check in wled_configure()
>       commit: b0fdeb96ead46de57a6226bc3a3ac7f9b50c0ace

Next time, please send subsequent patch versions independently.

-- 
Lee Jones [李琼斯]

Noted, thanks for the feedback! I’ll send subsequent versions as
independent patches in the future.

Best regards,
Henry


Lee Jones <lee@kernel.org> 于2025年4月4日周五 23:13写道：
>
> On Fri, 04 Apr 2025, Lee Jones wrote:
>
> > On Tue, 01 Apr 2025 17:16:47 +0800, Henry Martin wrote:
> > > devm_kasprintf() returns NULL when memory allocation fails. Currently,
> > > wled_configure() does not check for this case, which results in a NULL
> > > pointer dereference.
> > >
> > > Add NULL check after devm_kasprintf() to prevent this issue.
> > >
> > >
> > > [...]
> >
> > Applied, thanks!
> >
> > [1/1] backlight: pm8941: Add NULL check in wled_configure()
> >       commit: b0fdeb96ead46de57a6226bc3a3ac7f9b50c0ace
>
> Next time, please send subsequent patch versions independently.
>
> --
> Lee Jones [李琼斯]