2020-04-22 02:52:37

by Zou Wei

Subject: [PATCH -next] scsi: aacraid: Use memdup_user() as a cleanup

Fix coccicheck warning which recommends to use memdup_user().

This patch fixes the following coccicheck warnings:

drivers/scsi/aacraid/commctrl.c:516:15-22: WARNING opportunity for memdup_user

Fixes: 4645df1035b3 ("[PATCH] aacraid: swapped kmalloc args.")
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Zou Wei <[email protected]>
---
drivers/scsi/aacraid/commctrl.c | 14 +++-----------
1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/drivers/scsi/aacraid/commctrl.c b/drivers/scsi/aacraid/commctrl.c
index ffe41bc..1ce1620 100644
--- a/drivers/scsi/aacraid/commctrl.c
+++ b/drivers/scsi/aacraid/commctrl.c
@@ -513,17 +513,9 @@ static int aac_send_raw_srb(struct aac_dev* dev, void __user * arg)
goto cleanup;
}

- user_srbcmd = kmalloc(fibsize, GFP_KERNEL);
- if (!user_srbcmd) {
- dprintk((KERN_DEBUG"aacraid: Could not make a copy of the srb\n"));
- rcode = -ENOMEM;
- goto cleanup;
- }
- if(copy_from_user(user_srbcmd, user_srb,fibsize)){
- dprintk((KERN_DEBUG"aacraid: Could not copy srb from user\n"));
- rcode = -EFAULT;
- goto cleanup;
- }
+ user_srbcmd = memdup_user(user_srb, fibsize);
+ if (IS_ERR(user_srbcmd))
+ return PTR_ERR(user_srbcmd);

flags = user_srbcmd->flags; /* from user in cpu order */
switch (flags & (SRB_DataIn | SRB_DataOut)) {
--
2.6.2

2020-04-24 22:27:26

by Martin K. Petersen

Subject: Re: [PATCH -next] scsi: aacraid: Use memdup_user() as a cleanup

Zou,

> diff --git a/drivers/scsi/aacraid/commctrl.c b/drivers/scsi/aacraid/commctrl.c
> index ffe41bc..1ce1620 100644
> --- a/drivers/scsi/aacraid/commctrl.c
> +++ b/drivers/scsi/aacraid/commctrl.c
> @@ -513,17 +513,9 @@ static int aac_send_raw_srb(struct aac_dev* dev, void __user * arg)
> goto cleanup;
> }
>
> - user_srbcmd = kmalloc(fibsize, GFP_KERNEL);
> - if (!user_srbcmd) {
> - dprintk((KERN_DEBUG"aacraid: Could not make a copy of the srb\n"));
> - rcode = -ENOMEM;
> - goto cleanup;
> - }
> - if(copy_from_user(user_srbcmd, user_srb,fibsize)){
> - dprintk((KERN_DEBUG"aacraid: Could not copy srb from user\n"));
> - rcode = -EFAULT;
> - goto cleanup;
> - }
> + user_srbcmd = memdup_user(user_srb, fibsize);
> + if (IS_ERR(user_srbcmd))
> + return PTR_ERR(user_srbcmd);
>
> flags = user_srbcmd->flags; /* from user in cpu order */
> switch (flags & (SRB_DataIn | SRB_DataOut)) {

This is not equivalent, is it? The original code does a goto cleanup;
whereas your patch returns on error.

--
Martin K. Petersen Oracle Linux Engineering

2020-04-26 02:36:51

by Zou Wei

Subject: Re: [PATCH -next] scsi: aacraid: Use memdup_user() as a cleanup

Hi Martin,

Thanks for your review and reply.
You are right, it is not equivalent. I will keep the original goto
cleanup. But the return value is changed to use of PTR_ERR
(user_srbcmd), and assign it to rcode.
I will send the v2 soon later

On 2020/4/25 6:23, Martin K. Petersen wrote:
>
> Zou,
>
>> diff --git a/drivers/scsi/aacraid/commctrl.c b/drivers/scsi/aacraid/commctrl.c
>> index ffe41bc..1ce1620 100644
>> --- a/drivers/scsi/aacraid/commctrl.c
>> +++ b/drivers/scsi/aacraid/commctrl.c
>> @@ -513,17 +513,9 @@ static int aac_send_raw_srb(struct aac_dev* dev, void __user * arg)
>> goto cleanup;
>> }
>>
>> - user_srbcmd = kmalloc(fibsize, GFP_KERNEL);
>> - if (!user_srbcmd) {
>> - dprintk((KERN_DEBUG"aacraid: Could not make a copy of the srb\n"));
>> - rcode = -ENOMEM;
>> - goto cleanup;
>> - }
>> - if(copy_from_user(user_srbcmd, user_srb,fibsize)){
>> - dprintk((KERN_DEBUG"aacraid: Could not copy srb from user\n"));
>> - rcode = -EFAULT;
>> - goto cleanup;
>> - }
>> + user_srbcmd = memdup_user(user_srb, fibsize);
>> + if (IS_ERR(user_srbcmd))
>> + return PTR_ERR(user_srbcmd);
>>
>> flags = user_srbcmd->flags; /* from user in cpu order */
>> switch (flags & (SRB_DataIn | SRB_DataOut)) {
>
> This is not equivalent, is it? The original code does a goto cleanup;
> whereas your patch returns on error.
>