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 49F70242D70 for ; Sat, 25 Apr 2026 08:47:33 +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=1777106853; cv=none; b=LbV5RcE7ytH7LGq+Dydp+UVghYnkATnfXYw4QB1BolgMLoyYwtA/JcgPxYX0pd5DndZzNwUwEPy3mtK3e/bRoURTygD7e5ggyNYDc0oJPVPDblOVSwgWXyDPtrHfjndAJKSxyp1Tcx+6Yz0EY2a1yICPySA4mOasAiCUHjtoyN4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777106853; c=relaxed/simple; bh=tbye88apzcYMI4lfa7iZ2bx6NwN5LRKrRhnEFwpcydE=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=IFjS+MPkJs6YW/tTeYUuWpv6WOWPtZUqyIS9ughgbAb24cgF/nc4dX3l8hg6FL5xlAEcSEGIap2sw1/EUn5GJvXEtIxmZV7piJQx7IeiOpOqOidsg725HaCADzsokXVajctGCaAFUvFJYvYHV9k/y9w5L85O46MLMbd+oDJCpnI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=mXrdLBnq; 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="mXrdLBnq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9A04BC2BCB0; Sat, 25 Apr 2026 08:47:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1777106853; bh=tbye88apzcYMI4lfa7iZ2bx6NwN5LRKrRhnEFwpcydE=; h=From:To:Cc:Subject:Date:Reply-To:From; b=mXrdLBnqmLexTdNhPwThBM0zjopIk/b4LymEcCsl89ngZYSuwYXgKJavkz4cBQvPP JMSleOQDWbEua+DpaUtCIxaN2+2hQcP4d96CpzdpoXwpWNMUtympuUJNEKKKBOhFpY /jCvCdLYzPJLEvOVHuWk9f8DVSX75wo16xNY5nXg= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-31675: net/sched: sch_netem: fix out-of-bounds access in packet corruption Date: Sat, 25 Apr 2026 10:46:42 +0200 Message-ID: <2026042543-CVE-2026-31675-e5da@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=3125; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=E8fep4WVFpTJabozaTAqQ58K8HaXy+yrZ8iqSHRhLGw=; b=owGbwMvMwCRo6H6F97bub03G02pJDJlv6ouLVCfcXO1rOnGv9sTb2uurVMpiZ8dPCBS6JKL2P X1ClaNmRywLgyATg6yYIsuXbTxH91ccUvQytD0NM4eVCWQIAxenAExE7z7DPGPnrvNfkrrO9Sow 6H6eq3T9pWv5aoYFXTwFAhf5jIoXZUkI7hAt25HBJrMGAA== 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_netem: fix out-of-bounds access in packet corruption In netem_enqueue(), the packet corruption logic uses get_random_u32_below(skb_headlen(skb)) to select an index for modifying skb->data. When an AF_PACKET TX_RING sends fully non-linear packets over an IPIP tunnel, skb_headlen(skb) evaluates to 0. Passing 0 to get_random_u32_below() takes the variable-ceil slow path which returns an unconstrained 32-bit random integer. Using this unconstrained value as an offset into skb->data results in an out-of-bounds memory access. Fix this by verifying skb_headlen(skb) is non-zero before attempting to corrupt the linear data area. Fully non-linear packets will silently bypass the corruption logic. The Linux kernel CVE team has assigned CVE-2026-31675 to this issue. Affected and fixed versions =========================== Issue introduced in 2.6.16 with commit c865e5d99e25a171e8262fc0f7ba608568633c64 and fixed in 6.6.134 with commit a14b56863348686dd0387eea8ce66b85cf455908 Issue introduced in 2.6.16 with commit c865e5d99e25a171e8262fc0f7ba608568633c64 and fixed in 6.12.81 with commit 13a66ca1e235d4bcd53d12d4c68490cad7f8e46f Issue introduced in 2.6.16 with commit c865e5d99e25a171e8262fc0f7ba608568633c64 and fixed in 6.18.22 with commit 3a2999704ac36cfb4041fed3652d26a3373e8d12 Issue introduced in 2.6.16 with commit c865e5d99e25a171e8262fc0f7ba608568633c64 and fixed in 6.19.12 with commit 4fd258e281fa8bc15e9ce2c7691941537e9258ad Issue introduced in 2.6.16 with commit c865e5d99e25a171e8262fc0f7ba608568633c64 and fixed in 7.0 with commit d64cb81dcbd54927515a7f65e5e24affdc73c14b 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-2026-31675 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_netem.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/a14b56863348686dd0387eea8ce66b85cf455908 https://git.kernel.org/stable/c/13a66ca1e235d4bcd53d12d4c68490cad7f8e46f https://git.kernel.org/stable/c/3a2999704ac36cfb4041fed3652d26a3373e8d12 https://git.kernel.org/stable/c/4fd258e281fa8bc15e9ce2c7691941537e9258ad https://git.kernel.org/stable/c/d64cb81dcbd54927515a7f65e5e24affdc73c14b