[PATCH] scsi: ufs: ufshcd: fix potential NULL pointer dereference in ufshcd_config_vreg

[PATCH] scsi: ufs: ufshcd: fix potential NULL pointer dereference in ufshcd_config_vreg

[Gustavo A. R. Silva]

_vreg_ is being dereferenced before it is null checked, hence there is a
potential null pointer dereference.

Fix this by moving the pointer dereference after _vreg_ has been null
checked.

This issue was detected with the help of Coccinelle.

Fixes: aa4976130934 ("ufs: Add regulator enable support")
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
---
 drivers/scsi/ufs/ufshcd.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 011c336..a355d98 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -6559,12 +6559,15 @@ static int ufshcd_config_vreg(struct device *dev,
 		struct ufs_vreg *vreg, bool on)
 {
 	int ret = 0;
-	struct regulator *reg = vreg->reg;
-	const char *name = vreg->name;
+	struct regulator *reg;
+	const char *name;
 	int min_uV, uA_load;
 
 	BUG_ON(!vreg);
 
+	reg = vreg->reg;
+	name = vreg->name;
+
 	if (regulator_count_voltages(reg) > 0) {
 		min_uV = on ? vreg->min_uV : 0;
 		ret = regulator_set_voltage(reg, min_uV, vreg->max_uV);
-- 
2.7.4

Re: [PATCH] scsi: ufs: ufshcd: fix potential NULL pointer dereference in ufshcd_config_vreg

[Subhash Jadavani]

On 2017-11-20 06:12, Gustavo A. R. Silva wrote:
> _vreg_ is being dereferenced before it is null checked, hence there is 
> a
> potential null pointer dereference.
> 
> Fix this by moving the pointer dereference after _vreg_ has been null
> checked.
> 
> This issue was detected with the help of Coccinelle.
> 
> Fixes: aa4976130934 ("ufs: Add regulator enable support")
> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
> ---
>  drivers/scsi/ufs/ufshcd.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 011c336..a355d98 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -6559,12 +6559,15 @@ static int ufshcd_config_vreg(struct device 
> *dev,
>  		struct ufs_vreg *vreg, bool on)
>  {
>  	int ret = 0;
> -	struct regulator *reg = vreg->reg;
> -	const char *name = vreg->name;
> +	struct regulator *reg;
> +	const char *name;
>  	int min_uV, uA_load;
> 
>  	BUG_ON(!vreg);
> 
> +	reg = vreg->reg;
> +	name = vreg->name;
> +
>  	if (regulator_count_voltages(reg) > 0) {
>  		min_uV = on ? vreg->min_uV : 0;
>  		ret = regulator_set_voltage(reg, min_uV, vreg->max_uV);

Looks good to me.
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>


-- 
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH] scsi: ufs: ufshcd: fix potential NULL pointer dereference in ufshcd_config_vreg

[Martin K. Petersen]

Gustavo A.,

> _vreg_ is being dereferenced before it is null checked, hence there is a
> potential null pointer dereference.
>
> Fix this by moving the pointer dereference after _vreg_ has been null
> checked.

Applied to 4.15/scsi-fixes, thank you!

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH] scsi: ufs: ufshcd: fix potential NULL pointer dereference in ufshcd_config_vreg

[Gustavo A. R. Silva]

On 11/21/2017 10:01 PM, Martin K. Petersen wrote:
> Gustavo A.,
>
>> _vreg_ is being dereferenced before it is null checked, hence there is a
>> potential null pointer dereference.
>>
>> Fix this by moving the pointer dereference after _vreg_ has been null
>> checked.
> Applied to 4.15/scsi-fixes, thank you!
>

Glad to help. :)

Thanks
--
Gustavo A. R. Silva