Re: [PATCH v2] uio: uio_fsl_elbc_gpcm: Add NULL check in the uio_fsl_elbc_gpcm_probe()

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Apr 01, 2025 at 06:02:40PM +0800, Henry Martin wrote:
> devm_kasprintf() returns NULL when memory allocation fails. Currently,
> uio_fsl_elbc_gpcm_probe() does not check for this case, which results in
> a NULL pointer dereference.
> 
> Add NULL check after devm_kasprintf() to prevent this issue and ensuring
> no resources are left allocated.
> 
> Fixes: d57801c45f53 ("uio: uio_fsl_elbc_gpcm: use device-managed allocators")
> Signed-off-by: Henry Martin <bsdhenrymartin@gmail.com>
> ---
> V1 -> V2: Remove printk after memory failure and add proper resource
> cleanup.
> 
>  drivers/uio/uio_fsl_elbc_gpcm.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/uio/uio_fsl_elbc_gpcm.c b/drivers/uio/uio_fsl_elbc_gpcm.c
> index 81454c3e2484..26be556d956c 100644
> --- a/drivers/uio/uio_fsl_elbc_gpcm.c
> +++ b/drivers/uio/uio_fsl_elbc_gpcm.c
> @@ -384,6 +384,10 @@ static int uio_fsl_elbc_gpcm_probe(struct platform_device *pdev)
>  
>  	/* set all UIO data */
>  	info->mem[0].name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%pOFn", node);
> +	if (!info->mem[0].name) {
> +		ret = -ENOMEM;
> +		goto out_err3;
> +	}
>  	info->mem[0].addr = res.start;
>  	info->mem[0].size = resource_size(&res);
>  	info->mem[0].memtype = UIO_MEM_PHYS;
> @@ -423,6 +427,7 @@ static int uio_fsl_elbc_gpcm_probe(struct platform_device *pdev)
>  out_err2:
>  	if (priv->shutdown)
>  		priv->shutdown(info, true);
> +out_err3:
>  	iounmap(info->mem[0].internal_addr);
>  	return ret;
>  }
> -- 
> 2.34.1
> 

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)
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  Documentation/process/stable-kernel-rules.rst file for how to resolve
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If you wish to discuss this problem further, or you have questions about
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thanks,

greg k-h's patch email bot