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 B60AC36C5A9 for ; Sat, 15 Aug 2026 06:25:51 +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=1786775152; cv=none; b=Ls8PBOlEcJy01XtqZuaqke3QgojQ4jZYwwx9WSv2PwG12EDGNuQvUL7plqOElhkiYrwXx9hEUrApCzstpwdmcYnzZC7B+y/kOhjjtRh0hlWsK4HxszuaridPoi0CDKx/jH3IUxytCYZn+4b2HPV33jSBezubajvsFSiR+IB7NPw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786775152; c=relaxed/simple; bh=tQQqsvG6EQtCIzMvkwkZSdV1mH5l4i2th9jw/kyagls=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=lWM8/ahTOKqdknyPHb4Pi42tHnQuhM8QpNTg5TZPbF0fzceThPrsU8028br1KjDTclW7ZfIkRZ1Pe0VQ5Eiug5EG0ExzepoF1316oAtLH9D3X8RZtatIGm9Nuaqbxue+pU0v90/h69X79x2zleH23vWNof96RZ4clHkHZEs94/E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=YZmUBSzY; 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="YZmUBSzY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 107B21F000E9; Sat, 15 Aug 2026 06:25:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786775151; bh=7o85zcxY4bwkEhu8kKIa2MHc7+YWwbPxCbmGiNANd2U=; h=From:To:Cc:Subject:Date:Reply-To; b=YZmUBSzY+/6sh8+tGBbiCnDrN4sbkwlMbBvSs5jKXXXFWCLQClDnI0+PE6gNH7rqp ny04Yiblcr/315DGzYMzedO+O0DLKDPq2RR+KTZSJEELF82OBtWsKPcN0vxLI9MicF 0idkloyuIJ3PK5TDQAnBAgNRHGZ0+hD4T+UJUPM8= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-72390: net/sched: sch_teql: Introduce slaves_lock to avoid race condition and UAF Date: Sat, 15 Aug 2026 15:07:49 +0900 Message-ID: <2026081519-CVE-2026-72390-43ed@gregkh> X-Mailer: git-send-email 2.55.0 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=4466; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=U/0yocDe+Jza8H2U7te4SryJG1ivJCWDmF5xNQc0UHE=; b=owGbwMvMwCRo6H6F97bub03G02pJDFkNDK//pxzpYzPrVVbZ+N/U6ntJoVbuZpFp/Pbytxll1 K5pXRXsiGVhEGRikBVTZPmyjefo/opDil6Gtqdh5rAygQxh4OIUgIksj2GYyaij+vksr7yzzqHv YglB/55fDs5hY5hftMm8y/ISk9W+apanLqu1py5daGUFAA== 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_teql: Introduce slaves_lock to avoid race condition and UAF The teql master->slaves singly linked list is not protected against multiple writes. It can be mod'ed concurently from teql_master_xmit(), teql_dequeue(), teql_init() and teql_destroy() without holding any list lock or RCU protection. zdi-disclosures@trendmicro.com has demonstrated that the qdisc is freed after an RCU grace period, but teql_master_xmit() running on another CPU can still hold a stale pointer into the list, resulting in a slab-use-after-free: BUG: KASAN: slab-use-after-free in teql_master_xmit+0xf0f/0x16b0 Read of size 8 at addr ffff888013fb0440 by task poc/332 Freed 512-byte region [ffff888013fb0400, ffff888013fb0600) (kmalloc-512) The fix? Add a per-master slaves_lock spinlock that serializes all mutations of master->slaves and the NEXT_SLAVE() links in teql_destroy() and teql_qdisc_init(). teql_master_xmit() also takes the same slaves_lock around those updates. Annotate master->slaves and the per-slave ->next pointer with __rcu and use the appropriate RCU accessors everywhere they are touched: rcu_assign_pointer() on the writer side (under slaves_lock), rcu_dereference_protected() for the writer-side loads (also under slaves_lock), rcu_dereference_bh() for the loads in teql_master_xmit() and rtnl_dereference() for the loads in teql_master_open()/teql_master_mtu(), which run under RTNL. Pair this with rcu_read_lock_bh()/rcu_read_unlock_bh() around the list traversal in teql_master_xmit(), so that readers either observe a fully linked list or are deferred until the in-flight mutation completes. The two early-return paths in teql_master_xmit() are updated to release the RCU-bh read-side critical section before returning, since leaving it held would disable BH on that CPU for good. The Linux kernel CVE team has assigned CVE-2026-72390 to this issue. Affected and fixed versions =========================== Issue introduced in 2.6.12 with commit 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and fixed in 6.1.178 with commit 03c67781254c574ae7fa75e881239a78473bdf42 Issue introduced in 2.6.12 with commit 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and fixed in 6.6.145 with commit 735567bde7401f82b064f9f107b52ee1bf84ed8c Issue introduced in 2.6.12 with commit 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and fixed in 6.12.97 with commit 11402e6e18e96df615cbcc58157818dd604b23ff Issue introduced in 2.6.12 with commit 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and fixed in 6.18.40 with commit 9b7d05cbaa60108642402100efa6aa288dd33023 Issue introduced in 2.6.12 with commit 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and fixed in 7.1.5 with commit b26aa9d993537a4c3167d8ceead3b7c69c3a0aac Issue introduced in 2.6.12 with commit 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and fixed in 7.2-rc2 with commit e5b811fe793166aecc59b085c1b7c31262ef2316 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-2026-72390 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_teql.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/03c67781254c574ae7fa75e881239a78473bdf42 https://git.kernel.org/stable/c/735567bde7401f82b064f9f107b52ee1bf84ed8c https://git.kernel.org/stable/c/11402e6e18e96df615cbcc58157818dd604b23ff https://git.kernel.org/stable/c/9b7d05cbaa60108642402100efa6aa288dd33023 https://git.kernel.org/stable/c/b26aa9d993537a4c3167d8ceead3b7c69c3a0aac https://git.kernel.org/stable/c/e5b811fe793166aecc59b085c1b7c31262ef2316