From eede370d65ab8f5d0c6b2eb9c5213dd71710b18d Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Fri, 18 Jan 2019 10:46:18 -0800 Subject: net: ipv4: netconf: perform strict checks also for doit handlers Make RTM_GETNETCONF's doit handler use strict checks when NETLINK_F_STRICT_CHK is set. Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller --- net/ipv4/devinet.c | 43 +++++++++++++++++++++++++++++++++++++++---- 1 file changed, 39 insertions(+), 4 deletions(-) (limited to 'net') diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index e258a00b4a3d..cd027639df2f 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -2063,13 +2063,49 @@ static const struct nla_policy devconf_ipv4_policy[NETCONFA_MAX+1] = { [NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN] = { .len = sizeof(int) }, }; +static int inet_netconf_valid_get_req(struct sk_buff *skb, + const struct nlmsghdr *nlh, + struct nlattr **tb, + struct netlink_ext_ack *extack) +{ + int i, err; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(struct netconfmsg))) { + NL_SET_ERR_MSG(extack, "ipv4: Invalid header for netconf get request"); + return -EINVAL; + } + + if (!netlink_strict_get_check(skb)) + return nlmsg_parse(nlh, sizeof(struct netconfmsg), tb, + NETCONFA_MAX, devconf_ipv4_policy, extack); + + err = nlmsg_parse_strict(nlh, sizeof(struct netconfmsg), tb, + NETCONFA_MAX, devconf_ipv4_policy, extack); + if (err) + return err; + + for (i = 0; i <= NETCONFA_MAX; i++) { + if (!tb[i]) + continue; + + switch (i) { + case NETCONFA_IFINDEX: + break; + default: + NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in netconf get request"); + return -EINVAL; + } + } + + return 0; +} + static int inet_netconf_get_devconf(struct sk_buff *in_skb, struct nlmsghdr *nlh, struct netlink_ext_ack *extack) { struct net *net = sock_net(in_skb->sk); struct nlattr *tb[NETCONFA_MAX+1]; - struct netconfmsg *ncm; struct sk_buff *skb; struct ipv4_devconf *devconf; struct in_device *in_dev; @@ -2077,9 +2113,8 @@ static int inet_netconf_get_devconf(struct sk_buff *in_skb, int ifindex; int err; - err = nlmsg_parse(nlh, sizeof(*ncm), tb, NETCONFA_MAX, - devconf_ipv4_policy, extack); - if (err < 0) + err = inet_netconf_valid_get_req(in_skb, nlh, tb, extack); + if (err) goto errout; err = -EINVAL; -- cgit v1.2.3-59-g8ed1b