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 411EB5867E7 for ; Fri, 11 Sep 2026 19:56:11 +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=1789156584; cv=none; b=tYltjYkBscpw/8ZHEuZyGp+yQN+p90rm4jrIY97dXqtrPNUhu4k+R28M0vokIFPOUTopi7p8ZYVm/2KnTrnBqMsV4p7YJxhyRa8z5cwIpmbLZfxyFP0cJvzRemNIlPqoMm8Ig4f7Dse/tc+60o7l+AiAuzSLuLlaoY0fRsarf90= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789156584; c=relaxed/simple; bh=7WJkRujJNFMWa/iBHENGDf/Lr8ZBJQYWOtDqZDIGVfs=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=Nc9bWeekWgPfx3eRPEKqP2Xxt/7NSghxTiNmf2HTFYVhrovY9pe1K/2RWOboDmSVWSuhpE1q0lbHqwWt2cCatKm5D07vNazgMAbka6NtqErMuN3l0F00YKAdeKNAGTNaU6Ml+4twSf3/yx48XLsL/+r4lAhNkjgg1+VGgp5twDI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=rPd4Bu30; 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="rPd4Bu30" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 08E0F1F0089C; Fri, 11 Sep 2026 19:56:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789156571; bh=bvdDmu7h1yWGmqzFL/nbNUGnDhDlHQWH9gI7A2lSk7g=; h=From:To:Cc:Subject:Date:Reply-To; b=rPd4Bu30CAmGIh6vqDbPnyV/w9EV4vB8OCsYWbNkt2q2Ivzdb99zjRxPzN1irsBvc 8Nn5Z/++NThLnK2kXsv87+sB9Hqh4vpqTRm6off84LllZD8fWQdwJp/SQ64dvThzng 6PGJBFZaTQ1Y6swqwU3MhwOa4v4vZv/7hYUUhlxY= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89562: ip6_gre: fix hardware header length for NBMA tunnels Date: Fri, 11 Sep 2026 21:44:11 +0200 Message-ID: <2026091124-CVE-2026-89562-8003@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=3190; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=oXcf61BFSsdz++d/fC9WeB7gPvI7jkUjVKtMQ4FIgnw=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlLIlOsNk0Vttm+o862qp9pbXSaxFf/+j+eD9+JbPx++ OnvuSFTO2JZGASZGGTFFFm+bOM5ur/ikKKXoe1pmDmsTCBDGLg4BWAicp8Y5sqd3S4cyMu5LqKs 5tWEHqa9L6ImpjLMsyz9LfXEeOJbk0AJX6eTigqrk699BQA= 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: ip6_gre: fix hardware header length for NBMA tunnels ip6gre_tnl_link_config_route() accumulates the lower device's hardware header length into dev->hard_header_len whenever header_ops is set. This is incorrect for both users of header_ops. ip6gretap and ip6erspan have a fixed Ethernet hardware header length. For an NBMA ip6gre tunnel, ip6gre_header() creates only the GRE header, the optional FOU or GUE header, and the outer IPv6 header. The lower device header is headroom needed later, not part of the tunnel device's hardware header. Keep the lower device header in needed_headroom. Set hard_header_len to the tunnel header length only for ARPHRD_IP6GRE devices with header_ops, and leave the fixed Ethernet header length unchanged for tap and erspan devices. The Linux kernel CVE team has assigned CVE-2026-89562 to this issue. Affected and fixed versions =========================== Issue introduced in 5.10 with commit 832ba596494b2c9eac7760259eff2d8b7dcad0ee and fixed in 6.12.109 with commit 8bfe746afee38dd6e4348ddcd22d554789dbb9ff Issue introduced in 5.10 with commit 832ba596494b2c9eac7760259eff2d8b7dcad0ee and fixed in 6.18.50 with commit b8282668d8fa7c61b80e8e4890729031c291a16c Issue introduced in 5.10 with commit 832ba596494b2c9eac7760259eff2d8b7dcad0ee and fixed in 7.2.4 with commit 565038b0092f65afe384961c0f548d605bf438b9 Issue introduced in 5.10 with commit 832ba596494b2c9eac7760259eff2d8b7dcad0ee and fixed in 7.3-rc1 with commit 505b6d296c486ef7d1274f279d4c43a172f63224 Issue introduced in 4.19.162 with commit cf3d9717a5271573fa193c4dfa0df856295d5b15 Issue introduced in 5.4.82 with commit 187a6daf5db45adc807c85bbe285319107bed198 Issue introduced in 5.9.13 with commit d9897bb66ce989325b4bf4cdbb6a799e4ac878b6 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-2026-89562 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/ipv6/ip6_gre.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/8bfe746afee38dd6e4348ddcd22d554789dbb9ff https://git.kernel.org/stable/c/b8282668d8fa7c61b80e8e4890729031c291a16c https://git.kernel.org/stable/c/565038b0092f65afe384961c0f548d605bf438b9 https://git.kernel.org/stable/c/505b6d296c486ef7d1274f279d4c43a172f63224