net: kcm: fix incorrect parameter validation in the kcm_getsockopt) function

The 'len' variable can't be negative when assigned the result of
'min_t' because all 'min_t' parameters are cast to unsigned int,
and then the minimum one is chosen.

To fix the logic, check 'len' as read from 'optlen',
where the types of relevant variables are (signed) int.

Fixes: ab7ac4eb98 ("kcm: Kernel Connection Multiplexor module")
Signed-off-by: Gavrilov Ilia <Ilia.Gavrilov@infotecs.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Gavrilov Ilia 2024-03-07 14:23:50 +00:00 committed by David S. Miller
parent 4bb3ba7b74
commit 3ed5f41513

View File

@ -1153,10 +1153,11 @@ static int kcm_getsockopt(struct socket *sock, int level, int optname,
if (get_user(len, optlen))
return -EFAULT;
len = min_t(unsigned int, len, sizeof(int));
if (len < 0)
return -EINVAL;
len = min_t(unsigned int, len, sizeof(int));
switch (optname) {
case KCM_RECV_DISABLE:
val = kcm->rx_disabled;