[PATCH v2] usb: typec: tipd: Fix dereferencing freed memory 'fw in core.c

[PATCH v2] usb: typec: tipd: Fix dereferencing freed memory 'fw in core.c

[Dipendra Khadka]

Smatch reported dereferencing freed memory 'fw' in tps6598x_apply_patch().

Invoking relrease_firmware(fw) just after checking ret.

Fixes: 916b8e5fa73d ("usb: typec: tipd: add error log to provide firmware name and size")
Signed-off-by: Dipendra Khadka <kdipendra88@gmail.com>
---
v2:
 - Updated patch subject.
 - Updated patch description.
 - Added Fixes tag.
v1: 
 drivers/usb/typec/tipd/core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
index ea768b19a7f1..70bf8023ea35 100644
--- a/drivers/usb/typec/tipd/core.c
+++ b/drivers/usb/typec/tipd/core.c
@@ -1191,12 +1191,13 @@ static int tps6598x_apply_patch(struct tps6598x *tps)
 	dev_info(tps->dev, "Firmware update succeeded\n");
 
 release_fw:
-	release_firmware(fw);
 	if (ret) {
 		dev_err(tps->dev, "Failed to write patch %s of %zu bytes\n",
 			firmware_name, fw->size);
 	}
 
+	relrease_firmware(fw);
+
 	return ret;
 };
 
-- 
2.43.0

Re: [PATCH v2] usb: typec: tipd: Fix dereferencing freed memory 'fw in core.c

[Greg KH]

On Mon, Sep 23, 2024 at 09:26:24AM +0000, Dipendra Khadka wrote:
> Smatch reported dereferencing freed memory 'fw' in tps6598x_apply_patch().
> 
> Invoking relrease_firmware(fw) just after checking ret.
> 
> Fixes: 916b8e5fa73d ("usb: typec: tipd: add error log to provide firmware name and size")
> Signed-off-by: Dipendra Khadka <kdipendra88@gmail.com>


Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

You are receiving this message because of the following common error(s)
as indicated below:

- You have marked a patch with a "Fixes:" tag for a commit that is in an
  older released kernel, yet you do not have a cc: stable line in the
  signed-off-by area at all, which means that the patch will not be
  applied to any older kernel releases.  To properly fix this, please
  follow the documented rules in the
  Documentation/process/stable-kernel-rules.rst file for how to resolve
  this.

If you wish to discuss this problem further, or you have questions about
how to resolve this issue, please feel free to respond to this email and
Greg will reply once he has dug out from the pending patches received
from other developers.

thanks,

greg k-h's patch email bot

Re: [PATCH v2] usb: typec: tipd: Fix dereferencing freed memory 'fw in core.c

[Greg KH]

On Mon, Sep 23, 2024 at 09:26:24AM +0000, Dipendra Khadka wrote:
> Smatch reported dereferencing freed memory 'fw' in tps6598x_apply_patch().
> 
> Invoking relrease_firmware(fw) just after checking ret.
> 
> Fixes: 916b8e5fa73d ("usb: typec: tipd: add error log to provide firmware name and size")
> Signed-off-by: Dipendra Khadka <kdipendra88@gmail.com>
> ---
> v2:
>  - Updated patch subject.
>  - Updated patch description.
>  - Added Fixes tag.
> v1: 
>  drivers/usb/typec/tipd/core.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
> index ea768b19a7f1..70bf8023ea35 100644
> --- a/drivers/usb/typec/tipd/core.c
> +++ b/drivers/usb/typec/tipd/core.c
> @@ -1191,12 +1191,13 @@ static int tps6598x_apply_patch(struct tps6598x *tps)
>  	dev_info(tps->dev, "Firmware update succeeded\n");
>  
>  release_fw:
> -	release_firmware(fw);
>  	if (ret) {
>  		dev_err(tps->dev, "Failed to write patch %s of %zu bytes\n",
>  			firmware_name, fw->size);
>  	}
>  
> +	relrease_firmware(fw);

Any specific reason why you did not even compile this version of the
patch?

{sigh}