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

1 files changed, 4 insertions, 2 deletions

diff --git a/networking/libiproute/libnetlink.c b/networking/libiproute/libnetlink.c
index 861daef86..5545be8fe 100644
--- a/networking/libiproute/libnetlink.c
+++ b/networking/libiproute/libnetlink.c
@@ -161,7 +161,8 @@ int rtnl_dump_filter(struct rtnl_handle *rth,
                 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 @@ int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer,
                                 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);