net: socket: add check for negative optlen in compat setsockopt

__sys_setsockopt() already checks for `optlen < 0`. Add an equivalent check
to the compat path for robustness. This has to be `> INT_MAX` instead of
`< 0` because the signedness of `optlen` is different here.

Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jann Horn 2019-02-20 22:34:54 +01:00 committed by David S. Miller
parent f5b51fe804
commit 52baf9878b

View File

@ -388,8 +388,12 @@ static int __compat_sys_setsockopt(int fd, int level, int optname,
char __user *optval, unsigned int optlen)
{
int err;
struct socket *sock = sockfd_lookup(fd, &err);
struct socket *sock;
if (optlen > INT_MAX)
return -EINVAL;
sock = sockfd_lookup(fd, &err);
if (sock) {
err = security_socket_setsockopt(sock, level, optname);
if (err) {