[PATCH v3] iio: light: Add check for array bounds in veml6075_read_int_time_ms

[PATCH v3] iio: light: Add check for array bounds in veml6075_read_int_time_ms

[Karan Sanghavi]

The array contains only 5 elements, but the index calculated by
veml6075_read_int_time_index can range from 0 to 7,
which could lead to out-of-bounds access. The check prevents this issue.

Coverity Issue
CID 1574309: (#1 of 1): Out-of-bounds read (OVERRUN)
overrun-local: Overrunning array veml6075_it_ms of 5 4-byte
elements at element index 7 (byte offset 31) using
index int_index (which evaluates to 7)

Fixes: 3b82f43238ae ("iio: light: add VEML6075 UVA and UVB light sensor driver")
Signed-off-by: Karan Sanghavi <karansanghvi98@gmail.com>
---
 drivers/iio/light/veml6075.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/light/veml6075.c b/drivers/iio/light/veml6075.c
index 05d4c0e9015d..5dd951f6e989 100644
--- a/drivers/iio/light/veml6075.c
+++ b/drivers/iio/light/veml6075.c
@@ -201,7 +201,12 @@ static int veml6075_read_int_time_index(struct veml6075_data *data)
 	if (ret < 0)
 		return ret;
 
-	return FIELD_GET(VEML6075_CONF_IT, conf);
+	int int_index = FIELD_GET(VEML6075_CONF_IT, conf);
+
+	if (int_index >= ARRAY_SIZE(veml6075_it_ms))
+		return -EINVAL;
+
+	return int_index;
 }
 
 static int veml6075_read_int_time_ms(struct veml6075_data *data, int *val)
-- 
2.43.0

Re: [PATCH v3] iio: light: Add check for array bounds in veml6075_read_int_time_ms

[Javier Carrasco]

On Thu Feb 20, 2025 at 6:34 PM CET, Karan Sanghavi wrote:
> The array contains only 5 elements, but the index calculated by
> veml6075_read_int_time_index can range from 0 to 7,
> which could lead to out-of-bounds access. The check prevents this issue.
>
> Coverity Issue
> CID 1574309: (#1 of 1): Out-of-bounds read (OVERRUN)
> overrun-local: Overrunning array veml6075_it_ms of 5 4-byte
> elements at element index 7 (byte offset 31) using
> index int_index (which evaluates to 7)
>
> Fixes: 3b82f43238ae ("iio: light: add VEML6075 UVA and UVB light sensor driver")
> Signed-off-by: Karan Sanghavi <karansanghvi98@gmail.com>
> ---
>  drivers/iio/light/veml6075.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iio/light/veml6075.c b/drivers/iio/light/veml6075.c
> index 05d4c0e9015d..5dd951f6e989 100644
> --- a/drivers/iio/light/veml6075.c
> +++ b/drivers/iio/light/veml6075.c
> @@ -201,7 +201,12 @@ static int veml6075_read_int_time_index(struct veml6075_data *data)
>  	if (ret < 0)
>  		return ret;
>  
> -	return FIELD_GET(VEML6075_CONF_IT, conf);

Please declare the variable at the beginning of the function (there are
some integers there already) and rename it to follow the driver
convention, it for integration time: it_index

> +	int int_index = FIELD_GET(VEML6075_CONF_IT, conf);
> +
> +	if (int_index >= ARRAY_SIZE(veml6075_it_ms))
> +		return -EINVAL;
> +
> +	return int_index;
>  }
>  
>  static int veml6075_read_int_time_ms(struct veml6075_data *data, int *val)

With that applied:

Reviewed-by: Javier Carrasco <javier.carrasco@gmail.com>

Re: [PATCH v3] iio: light: Add check for array bounds in veml6075_read_int_time_ms

[Javier Carrasco]

On Thu Feb 20, 2025 at 9:00 PM CET, Javier Carrasco wrote:
> On Thu Feb 20, 2025 at 6:34 PM CET, Karan Sanghavi wrote:
> > The array contains only 5 elements, but the index calculated by
> > veml6075_read_int_time_index can range from 0 to 7,
> > which could lead to out-of-bounds access. The check prevents this issue.
> >
> > Coverity Issue
> > CID 1574309: (#1 of 1): Out-of-bounds read (OVERRUN)
> > overrun-local: Overrunning array veml6075_it_ms of 5 4-byte
> > elements at element index 7 (byte offset 31) using
> > index int_index (which evaluates to 7)
> >
> > Fixes: 3b82f43238ae ("iio: light: add VEML6075 UVA and UVB light sensor driver")
> > Signed-off-by: Karan Sanghavi <karansanghvi98@gmail.com>
> > ---
> >  drivers/iio/light/veml6075.c | 7 ++++++-
> >  1 file changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/iio/light/veml6075.c b/drivers/iio/light/veml6075.c
> > index 05d4c0e9015d..5dd951f6e989 100644
> > --- a/drivers/iio/light/veml6075.c
> > +++ b/drivers/iio/light/veml6075.c
> > @@ -201,7 +201,12 @@ static int veml6075_read_int_time_index(struct veml6075_data *data)
> >  	if (ret < 0)
> >  		return ret;
> >
> > -	return FIELD_GET(VEML6075_CONF_IT, conf);
>
> Please declare the variable at the beginning of the function (there are
> some integers there already) and rename it to follow the driver
> convention, it for integration time: it_index
>
> > +	int int_index = FIELD_GET(VEML6075_CONF_IT, conf);
> > +
> > +	if (int_index >= ARRAY_SIZE(veml6075_it_ms))
> > +		return -EINVAL;
> > +
> > +	return int_index;
> >  }
> >
> >  static int veml6075_read_int_time_ms(struct veml6075_data *data, int *val)
>
> With that applied:
>
> Reviewed-by: Javier Carrasco <javier.carrasco@gmail.com>

Fix:

Reviewed-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>

Re: [PATCH v3] iio: light: Add check for array bounds in veml6075_read_int_time_ms

[Jonathan Cameron]

On Thu, 20 Feb 2025 17:34:36 +0000
Karan Sanghavi <karansanghvi98@gmail.com> wrote:

> The array contains only 5 elements, but the index calculated by
> veml6075_read_int_time_index can range from 0 to 7,
> which could lead to out-of-bounds access. The check prevents this issue.
> 
> Coverity Issue
> CID 1574309: (#1 of 1): Out-of-bounds read (OVERRUN)
> overrun-local: Overrunning array veml6075_it_ms of 5 4-byte
> elements at element index 7 (byte offset 31) using
> index int_index (which evaluates to 7)
> 
> Fixes: 3b82f43238ae ("iio: light: add VEML6075 UVA and UVB light sensor driver")
> Signed-off-by: Karan Sanghavi <karansanghvi98@gmail.com>
> ---
Superficially this looks hardening against malicious or broken hardware.
That is fine to add, but not worth backporting or (in my opinion) adding a fixes
tag.

>  drivers/iio/light/veml6075.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/light/veml6075.c b/drivers/iio/light/veml6075.c
> index 05d4c0e9015d..5dd951f6e989 100644
> --- a/drivers/iio/light/veml6075.c
> +++ b/drivers/iio/light/veml6075.c
> @@ -201,7 +201,12 @@ static int veml6075_read_int_time_index(struct veml6075_data *data)
>  	if (ret < 0)
>  		return ret;
>  
> -	return FIELD_GET(VEML6075_CONF_IT, conf);
> +	int int_index = FIELD_GET(VEML6075_CONF_IT, conf);
> +
> +	if (int_index >= ARRAY_SIZE(veml6075_it_ms))
> +		return -EINVAL;
> +
> +	return int_index;
>  }
>  
>  static int veml6075_read_int_time_ms(struct veml6075_data *data, int *val)

Re: [PATCH v3] iio: light: Add check for array bounds in veml6075_read_int_time_ms

[Jonathan Cameron]

On Sat, 22 Feb 2025 16:43:37 +0000
Jonathan Cameron <jic23@kernel.org> wrote:

> On Thu, 20 Feb 2025 17:34:36 +0000
> Karan Sanghavi <karansanghvi98@gmail.com> wrote:
> 
> > The array contains only 5 elements, but the index calculated by
> > veml6075_read_int_time_index can range from 0 to 7,
> > which could lead to out-of-bounds access. The check prevents this issue.
> > 
> > Coverity Issue
> > CID 1574309: (#1 of 1): Out-of-bounds read (OVERRUN)
> > overrun-local: Overrunning array veml6075_it_ms of 5 4-byte
> > elements at element index 7 (byte offset 31) using
> > index int_index (which evaluates to 7)
> > 
> > Fixes: 3b82f43238ae ("iio: light: add VEML6075 UVA and UVB light sensor driver")
> > Signed-off-by: Karan Sanghavi <karansanghvi98@gmail.com>
> > ---  
> Superficially this looks hardening against malicious or broken hardware.
> That is fine to add, but not worth backporting or (in my opinion) adding a fixes
> tag.
Ah I see Javier asked for the fixes tag.  Ok.  Maybe just add a note that
the hardware is not expected to return such an out of bounds value.

That will help me to remember we don't need to rush this one upstream!

Jonathan

> 
> >  drivers/iio/light/veml6075.c | 7 ++++++-
> >  1 file changed, 6 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/iio/light/veml6075.c b/drivers/iio/light/veml6075.c
> > index 05d4c0e9015d..5dd951f6e989 100644
> > --- a/drivers/iio/light/veml6075.c
> > +++ b/drivers/iio/light/veml6075.c
> > @@ -201,7 +201,12 @@ static int veml6075_read_int_time_index(struct veml6075_data *data)
> >  	if (ret < 0)
> >  		return ret;
> >  
> > -	return FIELD_GET(VEML6075_CONF_IT, conf);
> > +	int int_index = FIELD_GET(VEML6075_CONF_IT, conf);
> > +
> > +	if (int_index >= ARRAY_SIZE(veml6075_it_ms))
> > +		return -EINVAL;
> > +
> > +	return int_index;
> >  }
> >  
> >  static int veml6075_read_int_time_ms(struct veml6075_data *data, int *val)  
> 

Re: [PATCH v3] iio: light: Add check for array bounds in veml6075_read_int_time_ms

[Jonathan Cameron]

On Sat, 22 Feb 2025 16:45:19 +0000
Jonathan Cameron <jic23@kernel.org> wrote:

> On Sat, 22 Feb 2025 16:43:37 +0000
> Jonathan Cameron <jic23@kernel.org> wrote:
> 
> > On Thu, 20 Feb 2025 17:34:36 +0000
> > Karan Sanghavi <karansanghvi98@gmail.com> wrote:
> >   
> > > The array contains only 5 elements, but the index calculated by
> > > veml6075_read_int_time_index can range from 0 to 7,
> > > which could lead to out-of-bounds access. The check prevents this issue.
> > > 
> > > Coverity Issue
> > > CID 1574309: (#1 of 1): Out-of-bounds read (OVERRUN)
> > > overrun-local: Overrunning array veml6075_it_ms of 5 4-byte
> > > elements at element index 7 (byte offset 31) using
> > > index int_index (which evaluates to 7)
> > > 
> > > Fixes: 3b82f43238ae ("iio: light: add VEML6075 UVA and UVB light sensor driver")
> > > Signed-off-by: Karan Sanghavi <karansanghvi98@gmail.com>
> > > ---    
> > Superficially this looks hardening against malicious or broken hardware.
> > That is fine to add, but not worth backporting or (in my opinion) adding a fixes
> > tag.  
> Ah I see Javier asked for the fixes tag.  Ok.  Maybe just add a note that
> the hardware is not expected to return such an out of bounds value.
> 
> That will help me to remember we don't need to rush this one upstream!
I guess you don't have time so I made the changes requested and applied.
(mostly so I can stop tracking the status!)

Jonathan

> 
> Jonathan
> 
> >   
> > >  drivers/iio/light/veml6075.c | 7 ++++++-
> > >  1 file changed, 6 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/iio/light/veml6075.c b/drivers/iio/light/veml6075.c
> > > index 05d4c0e9015d..5dd951f6e989 100644
> > > --- a/drivers/iio/light/veml6075.c
> > > +++ b/drivers/iio/light/veml6075.c
> > > @@ -201,7 +201,12 @@ static int veml6075_read_int_time_index(struct veml6075_data *data)
> > >  	if (ret < 0)
> > >  		return ret;
> > >  
> > > -	return FIELD_GET(VEML6075_CONF_IT, conf);
> > > +	int int_index = FIELD_GET(VEML6075_CONF_IT, conf);
> > > +
> > > +	if (int_index >= ARRAY_SIZE(veml6075_it_ms))
> > > +		return -EINVAL;
> > > +
> > > +	return int_index;
> > >  }
> > >  
> > >  static int veml6075_read_int_time_ms(struct veml6075_data *data, int *val)    
> >   
> 
>