2021-05-27 12:45:21

by Liu Shixin

[permalink] [raw]
Subject: [PATCH -next v2] media: pvrusb2: Replaced simple_strtol() with kstrtoint()

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 <[email protected]>
---
v1->v2: Fix subject line suggested by Hans. Thanks to Hans for advice.

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