[PATCH] scsi: ufs: fix potential memory leak

[PATCH] scsi: ufs: fix potential memory leak

[Tiezhu Yang]

There exists potential memory leak in ufshcd_parse_clock_info(),
this patch fixes it.

Signed-off-by: Tiezhu Yang <kernelpatch@126.com>
---
 drivers/scsi/ufs/ufshcd-pltfrm.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd-pltfrm.c b/drivers/scsi/ufs/ufshcd-pltfrm.c
index db53f38..8b057f4 100644
--- a/drivers/scsi/ufs/ufshcd-pltfrm.c
+++ b/drivers/scsi/ufs/ufshcd-pltfrm.c
@@ -100,19 +100,19 @@ static int ufshcd_parse_clock_info(struct ufs_hba *hba)
 	if (ret && (ret != -EINVAL)) {
 		dev_err(dev, "%s: error reading array %d\n",
 				"freq-table-hz", ret);
-		return ret;
+		goto out_free;
 	}
 
 	for (i = 0; i < sz; i += 2) {
 		ret = of_property_read_string_index(np,
 				"clock-names", i/2, (const char **)&name);
 		if (ret)
-			goto out;
+			goto out_free;
 
 		clki = devm_kzalloc(dev, sizeof(*clki), GFP_KERNEL);
 		if (!clki) {
 			ret = -ENOMEM;
-			goto out;
+			goto out_free;
 		}
 
 		clki->min_freq = clkfreq[i];
@@ -122,6 +122,10 @@ static int ufshcd_parse_clock_info(struct ufs_hba *hba)
 				clki->min_freq, clki->max_freq, clki->name);
 		list_add_tail(&clki->list, &hba->clk_list_head);
 	}
+
+out_free:
+	devm_kfree(dev, clkfreq);
+	clkfreq = NULL;
 out:
 	return ret;
 }
-- 
1.8.3.1

Re: [PATCH] scsi: ufs: fix potential memory leak

[James Bottomley]

On Wed, 2016-06-08 at 02:00 +0800, Tiezhu Yang wrote:
> There exists potential memory leak in ufshcd_parse_clock_info(),
> this patch fixes it.

What makes you think there's a leak here?  These are all devm_
allocations, so they're all freed when the device is.  If an error is
returned, the device is released and the memory freed.

You can argue that on successful initialization, there's no need to
keep the clkfreq array but this patch isn't the way you'd change that.

James

> Signed-off-by: Tiezhu Yang <kernelpatch@126.com>
> ---
>  drivers/scsi/ufs/ufshcd-pltfrm.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/scsi/ufs/ufshcd-pltfrm.c
> b/drivers/scsi/ufs/ufshcd-pltfrm.c
> index db53f38..8b057f4 100644
> --- a/drivers/scsi/ufs/ufshcd-pltfrm.c
> +++ b/drivers/scsi/ufs/ufshcd-pltfrm.c
> @@ -100,19 +100,19 @@ static int ufshcd_parse_clock_info(struct
> ufs_hba *hba)
>  	if (ret && (ret != -EINVAL)) {
>  		dev_err(dev, "%s: error reading array %d\n",
>  				"freq-table-hz", ret);
> -		return ret;
> +		goto out_free;
>  	}
>  
>  	for (i = 0; i < sz; i += 2) {
>  		ret = of_property_read_string_index(np,
>  				"clock-names", i/2, (const char
> **)&name);
>  		if (ret)
> -			goto out;
> +			goto out_free;
>  
>  		clki = devm_kzalloc(dev, sizeof(*clki), GFP_KERNEL);
>  		if (!clki) {
>  			ret = -ENOMEM;
> -			goto out;
> +			goto out_free;
>  		}
>  
>  		clki->min_freq = clkfreq[i];
> @@ -122,6 +122,10 @@ static int ufshcd_parse_clock_info(struct
> ufs_hba *hba)
>  				clki->min_freq, clki->max_freq, clki
> ->name);
>  		list_add_tail(&clki->list, &hba->clk_list_head);
>  	}
> +
> +out_free:
> +	devm_kfree(dev, clkfreq);
> +	clkfreq = NULL;
>  out:
>  	return ret;
>  }

Re: [PATCH] scsi: ufs: fix potential memory leak

[Tiezhu Yang]

At 2016-06-08 03:12:08, "James Bottomley" <James.Bottomley@HansenPartnership.com> wrote:
>On Wed, 2016-06-08 at 02:00 +0800, Tiezhu Yang wrote:
>> There exists potential memory leak in ufshcd_parse_clock_info(),
>> this patch fixes it.
>
>What makes you think there's a leak here?  These are all devm_
>allocations, so they're all freed when the device is.  If an error is
>returned, the device is released and the memory freed.
>
>You can argue that on successful initialization, there's no need to
>keep the clkfreq array but this patch isn't the way you'd change that.
>
>James
>
OK, thanks. I will send a v2 patch.