From 4775cc1f2d5abca894ac32774eefc22c45347d1c Mon Sep 17 00:00:00 2001 From: Mathias Krause Date: Wed, 28 Dec 2016 17:52:15 +0100 Subject: [PATCH] rtnl: stats - add missing netlink message size checks We miss to check if the netlink message is actually big enough to contain a struct if_stats_msg. Add a check to prevent userland from sending us short messages that would make us access memory beyond the end of the message. Fixes: 10c9ead9f3c6 ("rtnetlink: add new RTM_GETSTATS message to dump...") Signed-off-by: Mathias Krause Cc: Roopa Prabhu Signed-off-by: David S. Miller --- net/core/rtnetlink.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 18b5aae99bec..75e3ea7bda08 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -3898,6 +3898,9 @@ static int rtnl_stats_get(struct sk_buff *skb, struct nlmsghdr *nlh) u32 filter_mask; int err; + if (nlmsg_len(nlh) < sizeof(*ifsm)) + return -EINVAL; + ifsm = nlmsg_data(nlh); if (ifsm->ifindex > 0) dev = __dev_get_by_index(net, ifsm->ifindex); @@ -3947,6 +3950,9 @@ static int rtnl_stats_dump(struct sk_buff *skb, struct netlink_callback *cb) cb->seq = net->dev_base_seq; + if (nlmsg_len(cb->nlh) < sizeof(*ifsm)) + return -EINVAL; + ifsm = nlmsg_data(cb->nlh); filter_mask = ifsm->filter_mask; if (!filter_mask) -- 2.20.1