From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7A6DB41B37C; Wed, 4 Feb 2026 14:55:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770216950; cv=none; b=ZW9okyBsgzCwyU4GOrp0qsen5RbHu/rVQnCXcocIO/QvzoFI18Z8NNFHgKxT4SZTnHd6JuuCm1J9OG5DldLX61s7mNos9liPhXzinTcvwcA6WTNAFlTbAUzF8s5CYtTHP7E6ZZb3lxSyRKjQiitiCjegMctCmh7O+SsxEziLjps= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770216950; c=relaxed/simple; bh=7mliYGCPsuqcxLEe5Eu6QUqcxs4/RPJor7zwYhllef4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Nfw9eS/Bs3P3Z1g/6VpNu0AwmWIrUwFvg46c3lAYq5ugfopCLL0hfPinfbWYbE/gbZvVXaeEmToLaI3vaSELtyLGswKZooiTqN/n9LYxw0v/QYBaMmrCZ9TQ0+a0elZ7ACqIhG8/5ACucjr086wYHBqnQe+je/fZICqSFaHc618= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=AQURrCzZ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="AQURrCzZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C74FBC4CEF7; Wed, 4 Feb 2026 14:55:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1770216950; bh=7mliYGCPsuqcxLEe5Eu6QUqcxs4/RPJor7zwYhllef4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AQURrCzZY0FxeobrDaEjIyMJO+OXUZrLEg5FPPRTmeQxXZuaMxixFKg2JfC1gD+PG SJkXGxWmCj+o6xEEvy5CKuNR9M8dhayllXtGsVxr+smG96daQUPAbno9/6IlD5bhZA T0PGKC8kZJLNOhvWpJmp1bJ04q78cDGRrALZDxXk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jamal Hadi Salim , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15 080/206] net/sched: qfq: Use cl_is_active to determine whether class is active in qfq_rm_from_ag Date: Wed, 4 Feb 2026 15:38:31 +0100 Message-ID: <20260204143901.092732359@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260204143858.193781818@linuxfoundation.org> References: <20260204143858.193781818@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jamal Hadi Salim [ Upstream commit d837fbee92453fbb829f950c8e7cf76207d73f33 ] This is more of a preventive patch to make the code more consistent and to prevent possible exploits that employ child qlen manipulations on qfq. use cl_is_active instead of relying on the child qdisc's qlen to determine class activation. Fixes: 462dbc9101acd ("pkt_sched: QFQ Plus: fair-queueing service at DRR cost") Signed-off-by: Jamal Hadi Salim Link: https://patch.msgid.link/20260114160243.913069-3-jhs@mojatatu.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/sched/sch_qfq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/sched/sch_qfq.c b/net/sched/sch_qfq.c index d201bcb5edc42..8e5b30c447b86 100644 --- a/net/sched/sch_qfq.c +++ b/net/sched/sch_qfq.c @@ -375,7 +375,7 @@ static void qfq_rm_from_agg(struct qfq_sched *q, struct qfq_class *cl) /* Deschedule class and remove it from its parent aggregate. */ static void qfq_deact_rm_from_agg(struct qfq_sched *q, struct qfq_class *cl) { - if (cl->qdisc->q.qlen > 0) /* class is active */ + if (cl_is_active(cl)) /* class is active */ qfq_deactivate_class(q, cl); qfq_rm_from_agg(q, cl); -- 2.51.0