[PATCH] backlight: pcf50633: pdata may be a null pointer, null pointer dereference cause crash
Subsystems:
backlight class/subsystem , framebuffer layer , the rest
2036d
3 messages,
3 authors,
2021-02-02 · open the first message on its own page
Signed-off-by: Wenjia Zhao <redacted>
---
drivers/video/backlight/pcf50633-backlight.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/video/backlight/pcf50633-backlight.c b/drivers/video/backlight/pcf50633-backlight.c
index 540dd338..43267af 100644
--- a/drivers/video/backlight/pcf50633-backlight.c
+++ b/drivers/video/backlight/pcf50633-backlight.c @@ -127,7 +127,8 @@ static int pcf50633_bl_probe(struct platform_device *pdev)
platform_set_drvdata ( pdev , pcf_bl );
- pcf50633_reg_write ( pcf_bl -> pcf , PCF50633_REG_LEDDIM , pdata -> ramp_time ); + if ( pdata ) + pcf50633_reg_write ( pcf_bl -> pcf , PCF50633_REG_LEDDIM , pdata -> ramp_time );
/*
* Should be different from bl_props . brightness , so we do not exit --
2.7.4
On Mon, 01 Feb 2021, Wenjia Zhao wrote:
Please provide a suitable commit messages.
Describe the problem.
Describe the issue was found.
Describe the solution.
quoted hunk Signed-off-by: Wenjia Zhao <redacted>
---
drivers/video/backlight/pcf50633-backlight.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/video/backlight/pcf50633-backlight.c b/drivers/video/backlight/pcf50633-backlight.c
index 540dd338..43267af 100644
--- a/drivers/video/backlight/pcf50633-backlight.c
+++ b/drivers/video/backlight/pcf50633-backlight.c @@ -127,7 +127,8 @@ static int pcf50633_bl_probe(struct platform_device *pdev)
platform_set_drvdata ( pdev , pcf_bl );
- pcf50633_reg_write ( pcf_bl -> pcf , PCF50633_REG_LEDDIM , pdata -> ramp_time ); + if ( pdata ) + pcf50633_reg_write ( pcf_bl -> pcf , PCF50633_REG_LEDDIM , pdata -> ramp_time );
A tab should be 8 chars in Linux.
/*
* Should be different from bl_props.brightness, so we do not exit
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
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On Mon, Feb 01, 2021 at 08:41:38AM -0600, Wenjia Zhao wrote: Signed-off-by: Wenjia Zhao <redacted>
There should be a patch description here explaining why the patch
is needed and how it works.
quoted hunk ---
drivers/video/backlight/pcf50633-backlight.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/video/backlight/pcf50633-backlight.c b/drivers/video/backlight/pcf50633-backlight.c
index 540dd338..43267af 100644
--- a/drivers/video/backlight/pcf50633-backlight.c
+++ b/drivers/video/backlight/pcf50633-backlight.c @@ -127,7 +127,8 @@ static int pcf50633_bl_probe(struct platform_device *pdev)
platform_set_drvdata ( pdev , pcf_bl );
- pcf50633_reg_write ( pcf_bl -> pcf , PCF50633_REG_LEDDIM , pdata -> ramp_time ); + if ( pdata ) + pcf50633_reg_write ( pcf_bl -> pcf , PCF50633_REG_LEDDIM , pdata -> ramp_time );
Assuming you found this issue using a static analyzer then I think it
might be better to if an "if (!pdata) return -EINVAL" further up the
file instead.
In other words it is better to "document" (via the return code) that the
code does not support pdata == NULL than to add another untested code
path.
Daniel.