From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 21D29312837 for ; Wed, 24 Jun 2026 16:35:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782318917; cv=none; b=qEtfYSPuld38gYtDMhCU2W0EKECPRg3ZN6ZN9dwGVkjhGIIGBYdveTyXUUmgzR7nQkQMXnV6Imcc6EyEky8qjueVVwSBTCn9Rep7oZlxW/4vdqLkdNlrw54RJ8fuJcANQHrhEHoahadbcNQxR1QmQix8/qUcFtXMzv+nJRVgH+s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782318917; c=relaxed/simple; bh=dU0AibepYiL5dHlCN0QCQghfUpY3d1ZmAJRllKUwhb0=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=GZL+McwySq7WYjSOg1p0gdWAI46/psfHxNyWibmmmZWUINMljHuDxx9bwePMRrRwtC1SIx/xS3NEyWjGfWAdwDuqp4KHKS9Lm9M+jxNS9BidDwuhaHXTU/WJ8fW57pohyhWCjZqC/9ZrNaueflBtbsjzLMlgIuTUxT2Rp6WImEI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=gx+cZ/WC; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="gx+cZ/WC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 681751F000E9; Wed, 24 Jun 2026 16:35:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1782318916; bh=SKprpveI6lKHIRek7YtweCYSKAwGd4+zSSkHu/hx78k=; h=From:To:Cc:Subject:Date:Reply-To; b=gx+cZ/WC51Bcem9uEW0GNyAX6LbTUU42IaS0FUCNJIH7eTYTc28xBlk35I5ARPMPq fkhCqFy0x5F02qCkwvaWyVFK1oky8QkpbV1cNAcikKGU8mTsCOqzm1Ys8jf9Hp+ZGy hr/wrcS2cOd/5s8yYyVYcsMB9BG66NV/Tdev5X6o= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-52997: net/sched: sch_dualpi2: drain both C-queue and L-queue in dualpi2_change() Date: Wed, 24 Jun 2026 17:30:21 +0100 Message-ID: <2026062446-CVE-2026-52997-545a@gregkh> X-Mailer: git-send-email 2.54.0 Reply-To: , Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2900; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=+ynQpp82Sdcc//3qECSnftIPEt3qTltQJOyVwtxbRq8=; b=owGbwMvMwCRo6H6F97bub03G02pJDFk2rL96/Wf2+71aKHilW1jmT7j2hQuCaUEyh7pl+dvrT tlKpBzuiGVhEGRikBVTZPmyjefo/opDil6Gtqdh5rAygQxh4OIUgImcM2JYsGNTf/P/RSI/WvNb fF/11OQ4VIq/YVhw4Mr0m5UVV9MM5pp6BCY/mG8VockPAA== X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit From: Greg Kroah-Hartman Description =========== In the Linux kernel, the following vulnerability has been resolved: net/sched: sch_dualpi2: drain both C-queue and L-queue in dualpi2_change() Fix dualpi2_change() to correctly enforce updated limit and memlimit values after a configuration change of the dualpi2 qdisc. Before this patch, dualpi2_change() always attempted to dequeue packets via the root qdisc (C-queue) when reducing backlog or memory usage, and unconditionally assumed that a valid skb will be returned. When traffic classification results in packets being queued in the L-queue while the C-queue is empty, this leads to a NULL skb dereference during limit or memlimit enforcement. This is fixed by first dequeuing from the C-queue path if it is non-empty. Once the C-queue is empty, packets are dequeued directly from the L-queue. Return values from qdisc_dequeue_internal() are checked for both queues. When dequeuing from the L-queue, the parent qdisc qlen and backlog counters are updated explicitly to keep overall qdisc statistics consistent. The Linux kernel CVE team has assigned CVE-2026-52997 to this issue. Affected and fixed versions =========================== Issue introduced in 6.17 with commit 320d031ad6e4d67e8e1ab08ac71efda02bc85683 and fixed in 6.18.33 with commit 86cf2eba2056bcf9c41fba260e599bd95bf9943b Issue introduced in 6.17 with commit 320d031ad6e4d67e8e1ab08ac71efda02bc85683 and fixed in 7.0.10 with commit 3042add80c2c50bd127d570b83319af612efde65 Issue introduced in 6.17 with commit 320d031ad6e4d67e8e1ab08ac71efda02bc85683 and fixed in 7.1 with commit 478ed6b7d2577439c610f91fa8759a4c878a4264 Please see https://www.kernel.org for a full list of currently supported kernel versions by the kernel community. Unaffected versions might change over time as fixes are backported to older supported kernel versions. The official CVE entry at https://cve.org/CVERecord/?id=CVE-2026-52997 will be updated if fixes are backported, please check that for the most up to date information about this issue. Affected files ============== The file(s) affected by this issue are: net/sched/sch_dualpi2.c Mitigation ========== The Linux kernel CVE team recommends that you update to the latest stable kernel version for this, and many other bugfixes. Individual changes are never tested alone, but rather are part of a larger kernel release. Cherry-picking individual commits is not recommended or supported by the Linux kernel community at all. If however, updating to the latest release is impossible, the individual changes to resolve this issue can be found at these commits: https://git.kernel.org/stable/c/86cf2eba2056bcf9c41fba260e599bd95bf9943b https://git.kernel.org/stable/c/3042add80c2c50bd127d570b83319af612efde65 https://git.kernel.org/stable/c/478ed6b7d2577439c610f91fa8759a4c878a4264