[PATCH net-next 20/20] net/bridge: Update br_mdb_dump for strict data checking
From: David Ahern <dsahern@kernel.org>
Date: 2018-10-05 04:29:17
Subsystem:
ethernet bridge, networking [general], the rest · Maintainers:
Nikolay Aleksandrov, Ido Schimmel, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: David Ahern <redacted> Update br_mdb_dump for strict data checking. If the flag is set, the dump request is expected to have a br_port_msg struct as the header. All elements of the struct are expected to be 0 and no attributes can be appended. Signed-off-by: David Ahern <redacted> --- net/bridge/br_mdb.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+)
diff --git a/net/bridge/br_mdb.c b/net/bridge/br_mdb.c
index a4a848bf827b..7beeee658d6c 100644
--- a/net/bridge/br_mdb.c
+++ b/net/bridge/br_mdb.c@@ -162,6 +162,28 @@ static int br_mdb_fill_info(struct sk_buff *skb, struct netlink_callback *cb, return err; } +static int br_mdb_valid_dump_req(const struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct br_port_msg *bpm; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*bpm))) { + NL_SET_ERR_MSG(extack, "Invalid header"); + return -EINVAL; + } + if (bpm->ifindex) { + NL_SET_ERR_MSG(extack, + "Filtering by device index is not supported"); + return -EINVAL; + } + if (nlh->nlmsg_len != nlmsg_msg_size(sizeof(*bpm))) { + NL_SET_ERR_MSG(extack, "Invalid data after header"); + return -EINVAL; + } + + return 0; +} + static int br_mdb_dump(struct sk_buff *skb, struct netlink_callback *cb) { struct net_device *dev;
@@ -169,6 +191,13 @@ static int br_mdb_dump(struct sk_buff *skb, struct netlink_callback *cb) struct nlmsghdr *nlh = NULL; int idx = 0, s_idx; + if (cb->strict_check) { + int err = br_mdb_valid_dump_req(cb->nlh, cb->extack); + + if (err) + return err; + } + s_idx = cb->args[0]; rcu_read_lock();
--
2.11.0