[v2] av7110: check for negative array offset
Commit Message
info->num comes from the user. It's type int. If the user passes
in a negative value that would cause memory corruption.
Signed-off-by: Dan Carpenter <error27@gmail.com>
---
V2: change the check instead of making num and unsigned int
--
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Comments
Hi,
On Friday 07 January 2011 14:46:51 Dan Carpenter wrote:
> info->num comes from the user. It's type int. If the user passes
> in a negative value that would cause memory corruption.
>
> Signed-off-by: Dan Carpenter <error27@gmail.com>
> ---
> V2: change the check instead of making num and unsigned int
>
> diff --git a/drivers/media/dvb/ttpci/av7110_ca.c b/drivers/media/dvb/ttpci/av7110_ca.c
> index 122c728..923a8e2 100644
> --- a/drivers/media/dvb/ttpci/av7110_ca.c
> +++ b/drivers/media/dvb/ttpci/av7110_ca.c
> @@ -277,7 +277,7 @@ static int dvb_ca_ioctl(struct file *file, unsigned int cmd, void *parg)
> {
> ca_slot_info_t *info=(ca_slot_info_t *)parg;
>
> - if (info->num > 1)
> + if ((unsigned)info->num > 1)
> return -EINVAL;
> av7110->ci_slot[info->num].num = info->num;
> av7110->ci_slot[info->num].type = FW_CI_LL_SUPPORT(av7110->arm_app) ?
> --
> To unsubscribe from this list: send the line "unsubscribe linux-media" in
> the body of a message to majordomo@vger.kernel.org
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Imho casts are a last resort and should be avoided, if there is a better
way to do it. The obvious fix is
if (info->num < 0 || info->num > 1)
return -EINVAL;
CU
Oliver
@@ -277,7 +277,7 @@ static int dvb_ca_ioctl(struct file *file, unsigned int cmd, void *parg)
{
ca_slot_info_t *info=(ca_slot_info_t *)parg;
- if (info->num > 1)
+ if ((unsigned)info->num > 1)
return -EINVAL;
av7110->ci_slot[info->num].num = info->num;
av7110->ci_slot[info->num].type = FW_CI_LL_SUPPORT(av7110->arm_app) ?