From 297e77e53eadb332d5062913447b104a772dc33b Mon Sep 17 00:00:00 2001 From: Petr Machata Date: Thu, 10 Sep 2020 14:09:05 +0200 Subject: [PATCH] net: DCB: Validate DCB_ATTR_DCB_BUFFER argument The parameter passed via DCB_ATTR_DCB_BUFFER is a struct dcbnl_buffer. The field prio2buffer is an array of IEEE_8021Q_MAX_PRIORITIES bytes, where each value is a number of a buffer to direct that priority's traffic to. That value is however never validated to lie within the bounds set by DCBX_MAX_BUFFERS. The only driver that currently implements the callback is mlx5 (maintainers CCd), and that does not do any validation either, in particual allowing incorrect configuration if the prio2buffer value does not fit into 4 bits. Instead of offloading the need to validate the buffer index to drivers, do it right there in core, and bounce the request if the value is too large. CC: Parav Pandit CC: Saeed Mahameed Fixes: e549f6f9c098 ("net/dcb: Add dcbnl buffer attribute") Signed-off-by: Petr Machata Reviewed-by: Ido Schimmel Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller --- net/dcb/dcbnl.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/net/dcb/dcbnl.c b/net/dcb/dcbnl.c index 84dde5a2066e..16014ad19406 100644 --- a/net/dcb/dcbnl.c +++ b/net/dcb/dcbnl.c @@ -1426,6 +1426,7 @@ static int dcbnl_ieee_set(struct net_device *netdev, struct nlmsghdr *nlh, { const struct dcbnl_rtnl_ops *ops = netdev->dcbnl_ops; struct nlattr *ieee[DCB_ATTR_IEEE_MAX + 1]; + int prio; int err; if (!ops) @@ -1475,6 +1476,13 @@ static int dcbnl_ieee_set(struct net_device *netdev, struct nlmsghdr *nlh, struct dcbnl_buffer *buffer = nla_data(ieee[DCB_ATTR_DCB_BUFFER]); + for (prio = 0; prio < ARRAY_SIZE(buffer->prio2buffer); prio++) { + if (buffer->prio2buffer[prio] >= DCBX_MAX_BUFFERS) { + err = -EINVAL; + goto err; + } + } + err = ops->dcbnl_setbuffer(netdev, buffer); if (err) goto err; -- 2.34.1