netdev - [PATCH net 1/2] 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]

Message-Id: <20230703151038.157771-2-pctammela@mojatatu.com>
Date: Mon,  3 Jul 2023 12:10:37 -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,
	Pedro Tammela <pctammela@...atatu.com>
Subject: [PATCH net 1/2] net/sched: sch_qfq: reintroduce lmax bound check for MTU

Commit 25369891fcef deletes a check for the case where no 'lmax' is
specified which commit 3037933448f6 fixes 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")
Signed-off-by: Pedro Tammela <pctammela@...atatu.com>
---
 net/sched/sch_qfq.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/net/sched/sch_qfq.c b/net/sched/sch_qfq.c
index dfd9a99e6257..b624ae539c8c 100644
--- a/net/sched/sch_qfq.c
+++ b/net/sched/sch_qfq.c
@@ -425,8 +425,15 @@ static int qfq_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 
 	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