On 2020/4/14 14:54, Takashi Iwai wrote:
On Tue, 14 Apr 2020 08:51:09 +0200,
yangerkun wrote:
CVE-2020-11725 report that 'count = info->owner' may result a
SIZE_OVERFLOW. 'info->owner' represent a pid, and actually, we should
use info->count.
Signed-off-by: yangerkun <yangerkun@xxxxxxxxxx>
The CVE report is simply wrong. info->owner is used intentionally for
this specific API to add a user-space control. For the normal kernel
kctls, the field is used indeed for storing the pid, but but the
user-space kctl addition API usage is an exception.
You can see the another use of info->count of field in the very same
function at a later point and find it has a different meaning.
The CVE should be disputed.
Got it! Thanks for your reply.
thanks,
Takashi
---
sound/core/control.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
v1->v2: reword the patch head
diff --git a/sound/core/control.c b/sound/core/control.c
index aa0c0cf182af..c77ca7f39637 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -1431,7 +1431,7 @@ static int snd_ctl_elem_add(struct snd_ctl_file *file,
return -ENOMEM;
/* Check the number of elements for this userspace control. */
- count = info->owner;
+ count = info->count;
if (count == 0)
count = 1;
--
2.21.1
.
