| Message ID | 20150801123326.GA5075@mwanda |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Dan Carpenter <dan.carpenter@oracle.com> Date: Sat, 1 Aug 2015 15:33:26 +0300 > "len" is a signed integer. We check that len is not negative, so it > goes from zero to INT_MAX. PAGE_SIZE is unsigned long so the comparison > is type promoted to unsigned long. ULONG_MAX - 4095 is a higher than > INT_MAX so the condition can never be true. > > I don't know if this is harmful but it seems safe to limit "len" to > INT_MAX - 4095. > > Fixes: a8c879a7ee98 ('RDS: Info and stats') > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Applied, thanks Dan. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/rds/info.c b/net/rds/info.c index 9a6b4f6..140a44a 100644 --- a/net/rds/info.c +++ b/net/rds/info.c @@ -176,7 +176,7 @@ int rds_info_getsockopt(struct socket *sock, int optname, char __user *optval, /* check for all kinds of wrapping and the like */ start = (unsigned long)optval; - if (len < 0 || len + PAGE_SIZE - 1 < len || start + len < start) { + if (len < 0 || len > INT_MAX - PAGE_SIZE + 1 || start + len < start) { ret = -EINVAL; goto out; }
"len" is a signed integer. We check that len is not negative, so it goes from zero to INT_MAX. PAGE_SIZE is unsigned long so the comparison is type promoted to unsigned long. ULONG_MAX - 4095 is a higher than INT_MAX so the condition can never be true. I don't know if this is harmful but it seems safe to limit "len" to INT_MAX - 4095. Fixes: a8c879a7ee98 ('RDS: Info and stats') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html