netdev - [PATCH net v2 1/4] net/sched: sch_qfq: reintroduce lmax bound check for MTU

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

Date: Fri,  7 Jul 2023 18:59:57 -0300
From: Pedro Tammela <pctammela@...atatu.com>
To: netdev@...r.kernel.org
Cc: jhs@...atatu.com,
	xiyou.wangcong@...il.com,
	jiri@...nulli.us,
	davem@...emloft.net,
	edumazet@...gle.com,
	kuba@...nel.org,
	pabeni@...hat.com,
	shuah@...nel.org,
	shaozhengchao@...wei.com,
	victor@...atatu.com,
	simon.horman@...igine.com,
	paolo.valente@...more.it,
	Pedro Tammela <pctammela@...atatu.com>
Subject: [PATCH net v2 1/4] net/sched: sch_qfq: reintroduce lmax bound check for MTU

25369891fcef deletes a check for the case where no 'lmax' is
specified which 3037933448f6 previously fixed as 'lmax'
could be set to the device's MTU without any bound checking
for QFQ_LMAX_MIN and QFQ_LMAX_MAX. Therefore, reintroduce the check.

Fixes: 25369891fcef ("net/sched: sch_qfq: refactor parsing of netlink parameters")
Acked-by: Jamal Hadi Salim <jhs@...atatu.com>
Signed-off-by: Pedro Tammela <pctammela@...atatu.com>
---
 net/sched/sch_qfq.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/net/sched/sch_qfq.c b/net/sched/sch_qfq.c
index dfd9a99e6257..63a5b277c117 100644
--- a/net/sched/sch_qfq.c
+++ b/net/sched/sch_qfq.c
@@ -423,10 +423,17 @@ static int qfq_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 	else
 		weight = 1;
 
-	if (tb[TCA_QFQ_LMAX])
+	if (tb[TCA_QFQ_LMAX]) {
 		lmax = nla_get_u32(tb[TCA_QFQ_LMAX]);
-	else
+	} else {
+		/* MTU size is user controlled */
 		lmax = psched_mtu(qdisc_dev(sch));
+		if (lmax < QFQ_MIN_LMAX || lmax > QFQ_MAX_LMAX) {
+			NL_SET_ERR_MSG_MOD(extack,
+					   "MTU size out of bounds for qfq");
+			return -EINVAL;
+		}
+	}
 
 	inv_w = ONE_FP / weight;
 	weight = ONE_FP / inv_w;
-- 
2.39.2