diff mbox series

[v4,iwl-next] i40e: Use correct buffer size in i40e_dbg_command_read

Message ID 20231205095844.2532859-1-chentao@kylinos.cn
State New
Headers
Series [v4,iwl-next] i40e: Use correct buffer size in i40e_dbg_command_read |

Commit Message

Kunwu Chan Dec. 5, 2023, 9:58 a.m. UTC 
  The size of "i40e_dbg_command_buf" is 256, the size of "name"
depends on "IFNAMSIZ", plus a null character and format size,
the total size is more than 256.

Improve readability and maintainability by replacing a hardcoded string
allocation and formatting by the use of the kasprintf() helper.

Fixes: 02e9c290814c ("i40e: debugfs interface")
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Suggested-by: Simon Horman <horms@kernel.org>
Suggested-by: Alexander Lobakin <aleksander.lobakin@intel.com>
---
v2
   - Update the size calculation with IFNAMSIZ and sizeof(i40e_dbg_command_buf)
v3
   - Use kasprintf to improve readability and maintainability
v4
   - Fix memory leak in error path
---
 .../net/ethernet/intel/i40e/i40e_debugfs.c    | 20 ++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

Comments

Alexander Lobakin Dec. 6, 2023, 12:40 p.m. UTC | #1 
From: Kunwu Chan <chentao@kylinos.cn>
Date: Tue, 5 Dec 2023 17:58:44 +0800

> The size of "i40e_dbg_command_buf" is 256, the size of "name"
> depends on "IFNAMSIZ", plus a null character and format size,
> the total size is more than 256.
> 
> Improve readability and maintainability by replacing a hardcoded string
> allocation and formatting by the use of the kasprintf() helper.
> 
> Fixes: 02e9c290814c ("i40e: debugfs interface")
> Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
> Suggested-by: Simon Horman <horms@kernel.org>
> Suggested-by: Alexander Lobakin <aleksander.lobakin@intel.com>

Your Signed-off-by must be the last tag in the block.
Perhaps the maintainer could fix it when taking, so that you wouldn't
need to send a new version only due to that.

> ---
> v2
>    - Update the size calculation with IFNAMSIZ and sizeof(i40e_dbg_command_buf)
> v3
>    - Use kasprintf to improve readability and maintainability
> v4
>    - Fix memory leak in error path
> ---
>  .../net/ethernet/intel/i40e/i40e_debugfs.c    | 20 ++++++++++---------
>  1 file changed, 11 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/i40e/i40e_debugfs.c b/drivers/net/ethernet/intel/i40e/i40e_debugfs.c
> index 88240571721a..78a7200211b2 100644
> --- a/drivers/net/ethernet/intel/i40e/i40e_debugfs.c
> +++ b/drivers/net/ethernet/intel/i40e/i40e_debugfs.c
> @@ -72,29 +72,31 @@ static ssize_t i40e_dbg_command_read(struct file *filp, char __user *buffer,
>  {
>  	struct i40e_pf *pf = filp->private_data;
>  	int bytes_not_copied;
> -	int buf_size = 256;
>  	char *buf;
>  	int len;
>  
>  	/* don't allow partial reads */
>  	if (*ppos != 0)
>  		return 0;
> -	if (count < buf_size)
> -		return -ENOSPC;
>  
> -	buf = kzalloc(buf_size, GFP_KERNEL);
> +	buf = kasprintf(GFP_KERNEL, "%s: %s\n",
> +			pf->vsi[pf->lan_vsi]->netdev->name,
> +			i40e_dbg_command_buf);
>  	if (!buf)
>  		return -ENOSPC;
>  
> -	len = snprintf(buf, buf_size, "%s: %s\n",
> -		       pf->vsi[pf->lan_vsi]->netdev->name,
> -		       i40e_dbg_command_buf);
> +	len = strlen(buf) + 1;
> +	if (count < len)
> +		bytes_not_copied = -ENOSPC;
> +	else if (copy_to_user(buffer, buf, len))
> +		bytes_not_copied = -EFAULT;
> +	else
> +		bytes_not_copied = 0;
>  
> -	bytes_not_copied = copy_to_user(buffer, buf, len);
>  	kfree(buf);
>  
>  	if (bytes_not_copied)
> -		return -EFAULT;
> +		return bytes_not_copied;
>  
>  	*ppos = len;
>  	return len;

For the code:

Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>

Thanks,
Olek
Tony Nguyen Dec. 7, 2023, 11:25 p.m. UTC | #2 
On 12/6/2023 4:40 AM, Alexander Lobakin wrote:
> From: Kunwu Chan <chentao@kylinos.cn>
> Date: Tue, 5 Dec 2023 17:58:44 +0800
> 
>> The size of "i40e_dbg_command_buf" is 256, the size of "name"
>> depends on "IFNAMSIZ", plus a null character and format size,
>> the total size is more than 256.
>>
>> Improve readability and maintainability by replacing a hardcoded string
>> allocation and formatting by the use of the kasprintf() helper.
>>
>> Fixes: 02e9c290814c ("i40e: debugfs interface")
>> Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
>> Suggested-by: Simon Horman <horms@kernel.org>
>> Suggested-by: Alexander Lobakin <aleksander.lobakin@intel.com>
> 
> Your Signed-off-by must be the last tag in the block.
> Perhaps the maintainer could fix it when taking, so that you wouldn't
> need to send a new version only due to that.

You missed Intel Wired LAN (intel-wired-lan@lists.osuosl.org) on this, 
though the other versions did have it. Could you fix this up and be sure 
to include Intel Wired LAN?

Thanks,
Tony

>> ---
>> v2
>>     - Update the size calculation with IFNAMSIZ and sizeof(i40e_dbg_command_buf)
>> v3
>>     - Use kasprintf to improve readability and maintainability
>> v4
>>     - Fix memory leak in error path
Kunwu Chan Dec. 8, 2023, 2:05 a.m. UTC | #3 
Thanks for the reminder. It was my negligence.

I'll resend the v5 patch:
1. Keep 'Signed-off-by' be the last tag in the block
2. Cc to 'intel-wired-lan@lists.osuosl.org'
3. Cc to my personal email 'kunwu.chan@hotmail.com'

Thanks again,
Kunwu

On 2023/12/8 07:25, Tony Nguyen wrote:
> 
> 
> On 12/6/2023 4:40 AM, Alexander Lobakin wrote:
>> From: Kunwu Chan <chentao@kylinos.cn>
>> Date: Tue, 5 Dec 2023 17:58:44 +0800
>>
>>> The size of "i40e_dbg_command_buf" is 256, the size of "name"
>>> depends on "IFNAMSIZ", plus a null character and format size,
>>> the total size is more than 256.
>>>
>>> Improve readability and maintainability by replacing a hardcoded string
>>> allocation and formatting by the use of the kasprintf() helper.
>>>
>>> Fixes: 02e9c290814c ("i40e: debugfs interface")
>>> Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
>>> Suggested-by: Simon Horman <horms@kernel.org>
>>> Suggested-by: Alexander Lobakin <aleksander.lobakin@intel.com>
>>
>> Your Signed-off-by must be the last tag in the block.
>> Perhaps the maintainer could fix it when taking, so that you wouldn't
>> need to send a new version only due to that.
> 
> You missed Intel Wired LAN (intel-wired-lan@lists.osuosl.org) on this, 
> though the other versions did have it. Could you fix this up and be sure 
> to include Intel Wired LAN?
> 
> Thanks,
> Tony
> 
>>> ---
>>> v2
>>>     - Update the size calculation with IFNAMSIZ and 
>>> sizeof(i40e_dbg_command_buf)
>>> v3
>>>     - Use kasprintf to improve readability and maintainability
>>> v4
>>>     - Fix memory leak in error path
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/i40e/i40e_debugfs.c b/drivers/net/ethernet/intel/i40e/i40e_debugfs.c
index 88240571721a..78a7200211b2 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_debugfs.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_debugfs.c
@@ -72,29 +72,31 @@  static ssize_t i40e_dbg_command_read(struct file *filp, char __user *buffer,
 {
 	struct i40e_pf *pf = filp->private_data;
 	int bytes_not_copied;
-	int buf_size = 256;
 	char *buf;
 	int len;
 
 	/* don't allow partial reads */
 	if (*ppos != 0)
 		return 0;
-	if (count < buf_size)
-		return -ENOSPC;
 
-	buf = kzalloc(buf_size, GFP_KERNEL);
+	buf = kasprintf(GFP_KERNEL, "%s: %s\n",
+			pf->vsi[pf->lan_vsi]->netdev->name,
+			i40e_dbg_command_buf);
 	if (!buf)
 		return -ENOSPC;
 
-	len = snprintf(buf, buf_size, "%s: %s\n",
-		       pf->vsi[pf->lan_vsi]->netdev->name,
-		       i40e_dbg_command_buf);
+	len = strlen(buf) + 1;
+	if (count < len)
+		bytes_not_copied = -ENOSPC;
+	else if (copy_to_user(buffer, buf, len))
+		bytes_not_copied = -EFAULT;
+	else
+		bytes_not_copied = 0;
 
-	bytes_not_copied = copy_to_user(buffer, buf, len);
 	kfree(buf);
 
 	if (bytes_not_copied)
-		return -EFAULT;
+		return bytes_not_copied;
 
 	*ppos = len;
 	return len;