From d8a66aa25405e4e3015e4e4e856ef716585d59df Mon Sep 17 00:00:00 2001 From: David Ahern Date: Tue, 9 Oct 2018 11:10:43 -0700 Subject: net/mpls: Implement handler for strict data checking on dumps Without CONFIG_INET enabled compiles fail with: net/mpls/af_mpls.o: In function `mpls_dump_routes': af_mpls.c:(.text+0xed0): undefined reference to `ip_valid_fib_dump_req' The preference is for MPLS to use the same handler as ipv4 and ipv6 to allow consistency when doing a dump for AF_UNSPEC which walks all address families invoking the route dump handler. If INET is disabled then fallback to an MPLS version which can be tighter on the data checks. Fixes: e8ba330ac0c5 ("rtnetlink: Update fib dumps for strict data checking") Reported-by: Randy Dunlap Reported-by: Arnd Bergmann Signed-off-by: David Ahern Signed-off-by: David S. Miller --- net/mpls/af_mpls.c | 36 +++++++++++++++++++++++++++++++++++- 1 file changed, 35 insertions(+), 1 deletion(-) diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c index 7f891ffffc05..5fe274c47c41 100644 --- a/net/mpls/af_mpls.c +++ b/net/mpls/af_mpls.c @@ -2031,6 +2031,40 @@ nla_put_failure: return -EMSGSIZE; } +#if IS_ENABLED(CONFIG_INET) +static int mpls_valid_fib_dump_req(const struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + return ip_valid_fib_dump_req(nlh, extack); +} +#else +static int mpls_valid_fib_dump_req(const struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct rtmsg *rtm; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { + NL_SET_ERR_MSG_MOD(extack, "Invalid header for FIB dump request"); + return -EINVAL; + } + + rtm = nlmsg_data(nlh); + if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos || + rtm->rtm_table || rtm->rtm_protocol || rtm->rtm_scope || + rtm->rtm_type || rtm->rtm_flags) { + NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for FIB dump request"); + return -EINVAL; + } + + if (nlmsg_attrlen(nlh, sizeof(*rtm))) { + NL_SET_ERR_MSG_MOD(extack, "Invalid data after header in FIB dump request"); + return -EINVAL; + } + + return 0; +} +#endif + static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb) { const struct nlmsghdr *nlh = cb->nlh; @@ -2042,7 +2076,7 @@ static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb) ASSERT_RTNL(); if (cb->strict_check) { - int err = ip_valid_fib_dump_req(nlh, cb->extack); + int err = mpls_valid_fib_dump_req(nlh, cb->extack); if (err < 0) return err; -- cgit v1.2.3-58-ga151