From f1a9dbcb7d17bf0abb325cdc984957cfabc59693 Mon Sep 17 00:00:00 2001 From: Maher Azzouzi Date: Fri, 1 Aug 2025 17:18:57 -0700 Subject: [PATCH] net/sched: mqprio: fix stack out-of-bounds write in tc entry parsing MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit [ Upstream commit ffd2dc4c6c49ff4f1e5d34e454a6a55608104c17 ] 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") Reviewed-by: Eric Dumazet Signed-off-by: Maher Azzouzi Reviewed-by: Vladimir Oltean Link: https://patch.msgid.link/20250802001857.2702497-1-kuba@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- 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 51d4013b61219..f3e5ef9a95925 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), -- 2.47.3