Re: [PATCH v2 net-next 21/23] net/bridge: Update br_mdb_dump for strict data checking
From: Christian Brauner <christian@brauner.io>
Date: 2018-10-08 18:06:40
On Sun, Oct 07, 2018 at 08:16:42PM -0700, David Ahern wrote:
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>
Acked-by: Christian Brauner <christian@brauner.io>
quoted hunk ↗ jump to hunk
--- net/bridge/br_mdb.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+)diff --git a/net/bridge/br_mdb.c b/net/bridge/br_mdb.c index a4a848bf827b..a7ea2d431714 100644 --- a/net/bridge/br_mdb.c +++ b/net/bridge/br_mdb.c@@ -162,6 +162,29 @@ 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_MOD(extack, "Invalid header for mdb dump request"); + return -EINVAL; + } + + bpm = nlmsg_data(nlh); + if (bpm->ifindex) { + NL_SET_ERR_MSG_MOD(extack, "Filtering by device index is not supported for mdb dump request"); + return -EINVAL; + } + if (nlmsg_attrlen(nlh, sizeof(*bpm))) { + NL_SET_ERR_MSG(extack, "Invalid data after header in mdb dump request"); + return -EINVAL; + } + + return 0; +} + static int br_mdb_dump(struct sk_buff *skb, struct netlink_callback *cb) { struct net_device *dev;@@ -169,6 +192,13 @@ 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 < 0) + return err; + } + s_idx = cb->args[0]; rcu_read_lock();-- 2.11.0