Steve Grubb writes:
Hello,
Last November a bug was found in iproute. CAN-2003-0856 has more information.
Basically, netlink packets can come from any user. If a program performs action
based on netlink packets, they must be examined to make sure they came from the
place they are expected (the kernel).
Attached is a patch against pre8. Please apply this before releasing 1.00 final.
All users of busy box may be vulnerable to local attacks without it.
Best Regards,
Steve Grubb
diff --git a/networking/libiproute/libnetlink.c b/networking/libiproute/libnetlink.c
index 861daef..5545be8 100644
--- a/networking/libiproute/libnetlink.c
+++ b/networking/libiproute/libnetlink.c
@@ -161,7 +161,8 @@
while (NLMSG_OK(h, status)) {
int err;
- if (h->nlmsg_pid != rth->local.nl_pid ||
+ if (nladdr.nl_pid != 0 ||
+ h->nlmsg_pid != rth->local.nl_pid ||
h->nlmsg_seq != rth->dump) {
if (junk) {
err = junk(&nladdr, h, arg2);
@@ -270,7 +271,8 @@
bb_error_msg_and_die("!!!malformed message: len=%d", len);
}
- if (h->nlmsg_pid != rtnl->local.nl_pid ||
+ if (nladdr.nl_pid != peer ||
+ h->nlmsg_pid != rtnl->local.nl_pid ||
h->nlmsg_seq != seq) {
if (junk) {
l_err = junk(&nladdr, h, jarg);