From: MaherAzzouzi TCA_MQPRIO_TC_ENTRY_INDEX is validated using NLA_POLICY_MAX(NLA_U32, TC_QOPT_MAX_QUEUE), which allows the value TC_QOPT_MAX_QUEUE (16). This leads to a 4-byte out-of-bounds stack write in the fp[] array, which only has room for 16 elements (0–15). Fix this by changing the policy to allow only up to TC_QOPT_MAX_QUEUE - 1. Fixes: f62af20bed2d ("net/sched: mqprio: allow per-TC user input of FP adminStatus") Reported-by: Maher Azzouzi Signed-off-by: Maher Azzouzi --- net/sched/sch_mqprio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/sched/sch_mqprio.c b/net/sched/sch_mqprio.c index 51d4013b6121..f3e5ef9a9592 100644 --- a/net/sched/sch_mqprio.c +++ b/net/sched/sch_mqprio.c @@ -152,7 +152,7 @@ static int mqprio_parse_opt(struct net_device *dev, struct tc_mqprio_qopt *qopt, static const struct nla_policy mqprio_tc_entry_policy[TCA_MQPRIO_TC_ENTRY_MAX + 1] = { [TCA_MQPRIO_TC_ENTRY_INDEX] = NLA_POLICY_MAX(NLA_U32, - TC_QOPT_MAX_QUEUE), + TC_QOPT_MAX_QUEUE - 1), [TCA_MQPRIO_TC_ENTRY_FP] = NLA_POLICY_RANGE(NLA_U32, TC_FP_EXPRESS, TC_FP_PREEMPTIBLE), -- 2.34.1