tcp: fix incorrect parameter validation in the do_tcp_getsockopt() function

[ Upstream commit 716edc9706 ]

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: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Gavrilov Ilia <Ilia.Gavrilov@infotecs.ru>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
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 14:23:49 +00:00 committed by Sasha Levin
parent dfbdcf5b57
commit dee4e782e4

View file

@ -4011,11 +4011,11 @@ int do_tcp_getsockopt(struct sock *sk, int level,
if (copy_from_sockptr(&len, optlen, sizeof(int)))
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 TCP_MAXSEG:
val = tp->mss_cache;