Commit 6c58c881 authored Jul 25, 2023 by Lin Ma Committed by Jakub Kicinski Jul 26, 2023

net/sched: mqprio: Add length check for TCA_MQPRIO_{MAX/MIN}_RATE64



The nla_for_each_nested parsing in function mqprio_parse_nlattr() does
not check the length of the nested attribute. This can lead to an
out-of-attribute read and allow a malformed nlattr (e.g., length 0) to
be viewed as 8 byte integer and passed to priv->max_rate/min_rate.

This patch adds the check based on nla_len() when check the nla_type(),
which ensures that the length of these two attribute must equals
sizeof(u64).

Fixes: 4e8b86c0 ("mqprio: Introduce new hardware offload mode and shaper in mqprio")
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Link: https://lore.kernel.org/r/20230725024227.426561-1-linma@zju.edu.cn


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

parent 0f0fa27b

net/sched/sch_mqprio.c

+14 −0

Original line number	Diff line number	Diff line
		@@ -290,6 +290,13 @@ static int mqprio_parse_nlattr(struct Qdisc sch, struct tc_mqprio_qopt qopt,
		"Attribute type expected to be TCA_MQPRIO_MIN_RATE64");
		return -EINVAL;
		}

		if (nla_len(attr) != sizeof(u64)) {
		NL_SET_ERR_MSG_ATTR(extack, attr,
		"Attribute TCA_MQPRIO_MIN_RATE64 expected to have 8 bytes length");
		return -EINVAL;
		}

		if (i >= qopt->num_tc)
		break;
		priv->min_rate[i] = nla_get_u64(attr);
		@@ -312,6 +319,13 @@ static int mqprio_parse_nlattr(struct Qdisc sch, struct tc_mqprio_qopt qopt,
		"Attribute type expected to be TCA_MQPRIO_MAX_RATE64");
		return -EINVAL;
		}

		if (nla_len(attr) != sizeof(u64)) {
		NL_SET_ERR_MSG_ATTR(extack, attr,
		"Attribute TCA_MQPRIO_MAX_RATE64 expected to have 8 bytes length");
		return -EINVAL;
		}

		if (i >= qopt->num_tc)
		break;
		priv->max_rate[i] = nla_get_u64(attr);