devm_kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure.

Fixes: 46207ca24545 ("ASoC: SOF: pci: change the default firmware path when the community key is used")
Fixes: 25bbc0c59ee1 ("ASoC: SOF: Add path definition for external firmware libraries")
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
---
 sound/soc/sof/sof-pci-dev.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/sound/soc/sof/sof-pci-dev.c b/sound/soc/sof/sof-pci-dev.c
index 64b326e3ef85..75a9bfa5bfbe 100644
--- a/sound/soc/sof/sof-pci-dev.c
+++ b/sound/soc/sof/sof-pci-dev.c
@@ -282,6 +282,10 @@ int sof_pci_probe(struct pci_dev *pci, const struct pci_device_id *pci_id)
 			devm_kasprintf(dev, GFP_KERNEL, "%s/%s",
 				       sof_pdata->desc->default_fw_path[sof_pdata->ipc_type],
 				       "community");
+		if (!sof_pdata->fw_filename_prefix) {
+			ret = -ENOMEM;	
+			goto out;
+		}
 
 		dev_dbg(dev,
 			"Platform uses community key, changed fw path to %s\n",
@@ -303,6 +307,10 @@ int sof_pci_probe(struct pci_dev *pci, const struct pci_device_id *pci_id)
 				devm_kasprintf(dev, GFP_KERNEL, "%s/%s",
 					sof_pdata->desc->default_lib_path[sof_pdata->ipc_type],
 					"community");
+			if (!sof_pdata->fw_lib_prefix) {
+				ret = -ENOMEM;
+				goto out;
+			}
 
 			dev_dbg(dev,
 				"Platform uses community key, changed fw_lib path to %s\n",
-- 
2.34.1

On Thu, Nov 23, 2023 at 11:54:24PM +0800, Kunwu Chan wrote:
> devm_kasprintf() returns a pointer to dynamically allocated memory
> which can be NULL upon failure.

In addition to the issues others mentioned this doesn't apply against
current code, please check and resend.

Thanks for your reply.
I'll check the patch and modify it by a better way.

Thanks again,
Kunwu

On 2023/12/4 20:38, Mark Brown wrote:
> On Thu, Nov 23, 2023 at 11:54:24PM +0800, Kunwu Chan wrote:
>> devm_kasprintf() returns a pointer to dynamically allocated memory
>> which can be NULL upon failure.
> 
> In addition to the issues others mentioned this doesn't apply against
> current code, please check and resend.

On 23/11/2023 17:54, Kunwu Chan wrote:
> devm_kasprintf() returns a pointer to dynamically allocated memory
> which can be NULL upon failure.
> 
> Fixes: 46207ca24545 ("ASoC: SOF: pci: change the default firmware path when the community key is used")
> Fixes: 25bbc0c59ee1 ("ASoC: SOF: Add path definition for external firmware libraries")
> Signed-off-by: Kunwu Chan <chentao@kylinos.cn>

This patch cannot fix both commits as at 46207ca24545 the lib path was
not present.
Please don't bundle unrelated fixes, it makes maintainers life harder.

As a note: if the allocation fails it is not going to cause null
dereference as the code checks !sof_pdata->*_prefix to see if it is
provided (override) or not (use default).
At most it will cause the kernel to 'ignore' the path override, but if
this allocation fails this is least of our problem ;)

> ---
>  sound/soc/sof/sof-pci-dev.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/sound/soc/sof/sof-pci-dev.c b/sound/soc/sof/sof-pci-dev.c
> index 64b326e3ef85..75a9bfa5bfbe 100644
> --- a/sound/soc/sof/sof-pci-dev.c
> +++ b/sound/soc/sof/sof-pci-dev.c
> @@ -282,6 +282,10 @@ int sof_pci_probe(struct pci_dev *pci, const struct pci_device_id *pci_id)
>  			devm_kasprintf(dev, GFP_KERNEL, "%s/%s",
>  				       sof_pdata->desc->default_fw_path[sof_pdata->ipc_type],
>  				       "community");
> +		if (!sof_pdata->fw_filename_prefix) {
> +			ret = -ENOMEM;	
> +			goto out;
> +		}
>  
>  		dev_dbg(dev,
>  			"Platform uses community key, changed fw path to %s\n",
> @@ -303,6 +307,10 @@ int sof_pci_probe(struct pci_dev *pci, const struct pci_device_id *pci_id)
>  				devm_kasprintf(dev, GFP_KERNEL, "%s/%s",
>  					sof_pdata->desc->default_lib_path[sof_pdata->ipc_type],
>  					"community");
> +			if (!sof_pdata->fw_lib_prefix) {
> +				ret = -ENOMEM;
> +				goto out;
> +			}
>  
>  			dev_dbg(dev,
>  				"Platform uses community key, changed fw_lib path to %s\n",

-- 
Péter