On 13.03.2011 15:00, Changli Gao wrote: > On Fri, Mar 11, 2011 at 2:12 AM, Vasiliy Kulikov <segoon@xxxxxxxxxxxx> wrote: >> buffer string is copied from userspace. It is not checked whether it is >> zero terminated. This may lead to overflow inside of simple_strtoul(). >> >> It was introduced before the git epoch. Files "ipt_CLUSTERIP/*" are >> root writable only by default, however, on some setups permissions might be >> relaxed to e.g. network admin user. >> >> Signed-off-by: Vasiliy Kulikov <segoon@xxxxxxxxxxxx> >> --- >> Compile tested. >> >> net/ipv4/netfilter/ipt_CLUSTERIP.c | 1 + >> 1 files changed, 1 insertions(+), 0 deletions(-) >> >> diff --git a/net/ipv4/netfilter/ipt_CLUSTERIP.c b/net/ipv4/netfilter/ipt_CLUSTERIP.c >> index 403ca57..7aabf9a 100644 >> --- a/net/ipv4/netfilter/ipt_CLUSTERIP.c >> +++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c >> @@ -666,6 +666,7 @@ static ssize_t clusterip_proc_write(struct file *file, const char __user *input, >> >> if (copy_from_user(buffer, input, PROC_WRITELEN)) > > I think size should be used instead of PROC_WRITELEN. > > if (size > PROC_WRITELEN) > return -EIO; > if (copy_from_user(buffer, input, size)) > return -EFAULT; > buffer[size] = '\0'; I agree, otherwise we might have the situation that the userspace copy is crossing page boundaries into unmapped memory. -- To unsubscribe from this list: send the line "unsubscribe netfilter" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
