6.6-stable review patch. If anyone has any objections, please let me know.
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From: Maher Azzouzi maherazz04@gmail.com
[ 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 edumazet@google.com Signed-off-by: Maher Azzouzi maherazz04@gmail.com Reviewed-by: Vladimir Oltean vladimir.oltean@nxp.com Link: https://patch.msgid.link/20250802001857.2702497-1-kuba@kernel.org Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 793009f445c0..a0e3f3bae536 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),