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* [PATCH -next] [media] media: Replaced simple_strtol() with kstrtoint()
@ 2021-05-24 12:08 Liu Shixin
  2021-05-26 10:08 ` Hans Verkuil
  0 siblings, 1 reply; 2+ messages in thread
From: Liu Shixin @ 2021-05-24 12:08 UTC (permalink / raw)
  To: Mike Isely, Mauro Carvalho Chehab; +Cc: linux-media, linux-kernel, Liu Shixin

It looks like that memcpy() is a superfluous operation in
parse_token()/parse_mtoken(). Simple these two functions and
use kstrtoint() instead of simple_strtol() to avoid data
overflow.

Signed-off-by: Liu Shixin <liushixin2@huawei.com>
---
 drivers/media/usb/pvrusb2/pvrusb2-ctrl.c | 25 ++----------------------
 1 file changed, 2 insertions(+), 23 deletions(-)

diff --git a/drivers/media/usb/pvrusb2/pvrusb2-ctrl.c b/drivers/media/usb/pvrusb2/pvrusb2-ctrl.c
index 9f71d8c2a3c6..8ae3ad80cccb 100644
--- a/drivers/media/usb/pvrusb2/pvrusb2-ctrl.c
+++ b/drivers/media/usb/pvrusb2/pvrusb2-ctrl.c
@@ -355,11 +355,8 @@ static int parse_token(const char *ptr,unsigned int len,
 		       int *valptr,
 		       const char * const *names, unsigned int namecnt)
 {
-	char buf[33];
 	unsigned int slen;
 	unsigned int idx;
-	int negfl;
-	char *p2;
 	*valptr = 0;
 	if (!names) namecnt = 0;
 	for (idx = 0; idx < namecnt; idx++) {
@@ -370,18 +367,7 @@ static int parse_token(const char *ptr,unsigned int len,
 		*valptr = idx;
 		return 0;
 	}
-	negfl = 0;
-	if ((*ptr == '-') || (*ptr == '+')) {
-		negfl = (*ptr == '-');
-		ptr++; len--;
-	}
-	if (len >= sizeof(buf)) return -EINVAL;
-	memcpy(buf,ptr,len);
-	buf[len] = 0;
-	*valptr = simple_strtol(buf,&p2,0);
-	if (negfl) *valptr = -(*valptr);
-	if (*p2) return -EINVAL;
-	return 1;
+	return kstrtoint(ptr, 0, valptr) ? -EINVAL : 1;
 }
 
 
@@ -389,10 +375,8 @@ static int parse_mtoken(const char *ptr,unsigned int len,
 			int *valptr,
 			const char **names,int valid_bits)
 {
-	char buf[33];
 	unsigned int slen;
 	unsigned int idx;
-	char *p2;
 	int msk;
 	*valptr = 0;
 	for (idx = 0, msk = 1; valid_bits; idx++, msk <<= 1) {
@@ -405,12 +389,7 @@ static int parse_mtoken(const char *ptr,unsigned int len,
 		*valptr = msk;
 		return 0;
 	}
-	if (len >= sizeof(buf)) return -EINVAL;
-	memcpy(buf,ptr,len);
-	buf[len] = 0;
-	*valptr = simple_strtol(buf,&p2,0);
-	if (*p2) return -EINVAL;
-	return 0;
+	return kstrtoint(ptr, 0, valptr);
 }
 
 
-- 
2.18.0.huawei.25


^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH -next] [media] media: Replaced simple_strtol() with kstrtoint()
  2021-05-24 12:08 [PATCH -next] [media] media: Replaced simple_strtol() with kstrtoint() Liu Shixin
@ 2021-05-26 10:08 ` Hans Verkuil
  0 siblings, 0 replies; 2+ messages in thread
From: Hans Verkuil @ 2021-05-26 10:08 UTC (permalink / raw)
  To: Liu Shixin, Mike Isely, Mauro Carvalho Chehab; +Cc: linux-media, linux-kernel

On 24/05/2021 14:08, Liu Shixin wrote:
> It looks like that memcpy() is a superfluous operation in
> parse_token()/parse_mtoken(). Simple these two functions and
> use kstrtoint() instead of simple_strtol() to avoid data
> overflow.

Always mention which driver you are changing in the subject line.
Just saying 'media:' suggests a subsystem-wide patch, but this is
just for a single driver.

Regards,

	Hans

> 
> Signed-off-by: Liu Shixin <liushixin2@huawei.com>
> ---
>  drivers/media/usb/pvrusb2/pvrusb2-ctrl.c | 25 ++----------------------
>  1 file changed, 2 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/media/usb/pvrusb2/pvrusb2-ctrl.c b/drivers/media/usb/pvrusb2/pvrusb2-ctrl.c
> index 9f71d8c2a3c6..8ae3ad80cccb 100644
> --- a/drivers/media/usb/pvrusb2/pvrusb2-ctrl.c
> +++ b/drivers/media/usb/pvrusb2/pvrusb2-ctrl.c
> @@ -355,11 +355,8 @@ static int parse_token(const char *ptr,unsigned int len,
>  		       int *valptr,
>  		       const char * const *names, unsigned int namecnt)
>  {
> -	char buf[33];
>  	unsigned int slen;
>  	unsigned int idx;
> -	int negfl;
> -	char *p2;
>  	*valptr = 0;
>  	if (!names) namecnt = 0;
>  	for (idx = 0; idx < namecnt; idx++) {
> @@ -370,18 +367,7 @@ static int parse_token(const char *ptr,unsigned int len,
>  		*valptr = idx;
>  		return 0;
>  	}
> -	negfl = 0;
> -	if ((*ptr == '-') || (*ptr == '+')) {
> -		negfl = (*ptr == '-');
> -		ptr++; len--;
> -	}
> -	if (len >= sizeof(buf)) return -EINVAL;
> -	memcpy(buf,ptr,len);
> -	buf[len] = 0;
> -	*valptr = simple_strtol(buf,&p2,0);
> -	if (negfl) *valptr = -(*valptr);
> -	if (*p2) return -EINVAL;
> -	return 1;
> +	return kstrtoint(ptr, 0, valptr) ? -EINVAL : 1;
>  }
>  
>  
> @@ -389,10 +375,8 @@ static int parse_mtoken(const char *ptr,unsigned int len,
>  			int *valptr,
>  			const char **names,int valid_bits)
>  {
> -	char buf[33];
>  	unsigned int slen;
>  	unsigned int idx;
> -	char *p2;
>  	int msk;
>  	*valptr = 0;
>  	for (idx = 0, msk = 1; valid_bits; idx++, msk <<= 1) {
> @@ -405,12 +389,7 @@ static int parse_mtoken(const char *ptr,unsigned int len,
>  		*valptr = msk;
>  		return 0;
>  	}
> -	if (len >= sizeof(buf)) return -EINVAL;
> -	memcpy(buf,ptr,len);
> -	buf[len] = 0;
> -	*valptr = simple_strtol(buf,&p2,0);
> -	if (*p2) return -EINVAL;
> -	return 0;
> +	return kstrtoint(ptr, 0, valptr);
>  }
>  
>  
> 


^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2021-05-26 10:08 UTC | newest]

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2021-05-24 12:08 [PATCH -next] [media] media: Replaced simple_strtol() with kstrtoint() Liu Shixin
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