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

[ Upstream commit 3ed5f41513 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Gavrilov Ilia 2024-03-07 14:23:50 +00:00 committed by Sasha Levin
parent 3a32dce1ad
commit 382df231ab

View File

@ -1275,10 +1275,11 @@ 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;