From: Petr Machata petrm@nvidia.com
[ Upstream commit 297e77e53eadb332d5062913447b104a772dc33b ]
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 parav@nvidia.com CC: Saeed Mahameed saeedm@nvidia.com Fixes: e549f6f9c098 ("net/dcb: Add dcbnl buffer attribute") Signed-off-by: Petr Machata petrm@nvidia.com Reviewed-by: Ido Schimmel idosch@nvidia.com Reviewed-by: Jiri Pirko jiri@nvidia.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/dcb/dcbnl.c | 8 ++++++++ 1 file changed, 8 insertions(+)
--- a/net/dcb/dcbnl.c +++ b/net/dcb/dcbnl.c @@ -1421,6 +1421,7 @@ static int dcbnl_ieee_set(struct net_dev { const struct dcbnl_rtnl_ops *ops = netdev->dcbnl_ops; struct nlattr *ieee[DCB_ATTR_IEEE_MAX + 1]; + int prio; int err;
if (!ops) @@ -1469,6 +1470,13 @@ static int dcbnl_ieee_set(struct net_dev 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;