netdev - [PATCH net] net/sched: taprio: always validate TCA_TAPRIO_ATTR

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240604181511.769870-1-edumazet@google.com>
Date: Tue,  4 Jun 2024 18:15:11 +0000
From: Eric Dumazet <edumazet@...gle.com>
To: "David S . Miller" <davem@...emloft.net>, Jakub Kicinski <kuba@...nel.org>, 
	Paolo Abeni <pabeni@...hat.com>
Cc: Jamal Hadi Salim <jhs@...atatu.com>, Cong Wang <xiyou.wangcong@...il.com>, 
	Jiri Pirko <jiri@...nulli.us>, netdev@...r.kernel.org, eric.dumazet@...il.com, 
	Eric Dumazet <edumazet@...gle.com>, Noam Rathaus <noamr@...-disclosure.com>, 
	Vinicius Costa Gomes <vinicius.gomes@...el.com>, Vladimir Oltean <vladimir.oltean@....com>
Subject: [PATCH net] net/sched: taprio: always validate TCA_TAPRIO_ATTR_PRIOMAP

If one TCA_TAPRIO_ATTR_PRIOMAP attribute has been provided,
taprio_parse_mqprio_opt() must validate it, or userspace
can inject arbitrary data to the kernel, the second time
taprio_change() is called.

First call (with valid attributes) sets dev->num_tc
to a non zero value.

Second call (with arbitrary mqprio attributes)
returns early from taprio_parse_mqprio_opt()
and bad things can happen.

Fixes: a3d43c0d56f1 ("taprio: Add support adding an admin schedule")
Reported-by: Noam Rathaus <noamr@...-disclosure.com>
Signed-off-by: Eric Dumazet <edumazet@...gle.com>
Cc: Vinicius Costa Gomes <vinicius.gomes@...el.com>
Cc: Vladimir Oltean <vladimir.oltean@....com>
---
 net/sched/sch_taprio.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
index 937a0c513c17..b284a06b5a75 100644
--- a/net/sched/sch_taprio.c
+++ b/net/sched/sch_taprio.c
@@ -1176,16 +1176,13 @@ static int taprio_parse_mqprio_opt(struct net_device *dev,
 {
 	bool allow_overlapping_txqs = TXTIME_ASSIST_IS_ENABLED(taprio_flags);
 
-	if (!qopt && !dev->num_tc) {
-		NL_SET_ERR_MSG(extack, "'mqprio' configuration is necessary");
-		return -EINVAL;
-	}
-
-	/* If num_tc is already set, it means that the user already
-	 * configured the mqprio part
-	 */
-	if (dev->num_tc)
+	if (!qopt) {
+		if (!dev->num_tc) {
+			NL_SET_ERR_MSG(extack, "'mqprio' configuration is necessary");
+			return -EINVAL;
+		}
 		return 0;
+	}
 
 	/* taprio imposes that traffic classes map 1:n to tx queues */
 	if (qopt->num_tc > dev->num_tx_queues) {
-- 
2.45.2.505.gda0bf45e8d-goog