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 069DE4519BA for ; Fri, 25 Sep 2026 10:30:32 +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=1790332233; cv=none; b=Nm/DkMZN49L/37nv0MmV7iVBRmgJQGDLqVX+GHIPSdMVBkcVC+S/pmCX0MCgRa4OU+2+EgvEIJdLtN83GpgRBDPPuptgFmfN0ek7qx8+Z5sMdlDtbHJdxwLJABN0wtCQW9nq/VJPvCXyYqFCo0mTclYVrQuGEOkrmmGx0bP7u5o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790332233; c=relaxed/simple; bh=4WQmmAwqC3sxWEDmjFNZkvSoNUwPX7Ow1yfOIa0yLao=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=BplRbQwOdUfQrRwkECaCoSnLFwk4Oh7R76NvrB9N8hWF4YTmLfpRIi12YXUZ568ZerQYcEK/8l2FkLv069FfqrQQ98eZ5BgH+BOTVUB2em35RE40r/5OAj11Ni8wTmc24ibdOGQ6yszzGohjbatdQYsRRz5JKY8gL4zgoC0aiYo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=mEIWlwrD; 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="mEIWlwrD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5CEC11F000FF; Fri, 25 Sep 2026 10:30:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790332231; bh=IRSJcJxXDtof5AB/u/8I+X9165Dp5z+S7NZgUDJWMLc=; h=From:To:Cc:Subject:Date:Reply-To; b=mEIWlwrDY58w6j5R9QurrXRKRmih1Ryl3kCdUiKTZl9z4SjpEgZwVeh9iXcnIvzpD EWWKB3QwWULQ8GZ3U80yODecfWvnFRzcv1XU1Sb8zgdDoKPJmd9i1mnOV1kLm7Y5vK 0c3OjbbOtEwWjlQuX3A2/3AEJsWiqx6ZpwJpxGos= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-97965: vxlan: initialize _md in vxlan_xmit_one() Date: Fri, 25 Sep 2026 12:24:28 +0200 Message-ID: <2026092516-CVE-2026-97965-aedb@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=3713; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=qPLNtNK7kcgdhZuJqqgcKe4orM0yIlY1rsfxaK3XB1g=; b=owGbwMvMwCRo6H6F97bub03G02pJDFnbvCPuzPz75GbAlvcydim39fgLn9/p55CJaVk284fFy 6QeDvtnHbEsDIJMDLJiiixftvEc3V9xSNHL0PY0zBxWJpAhDFycAjCRQ1sZ5mfbN/5a6flLX+VG e3o5e/nZhcF7WBjm55bpLlmcafp84xajt2KndtWyLd56AQA= 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: vxlan: initialize _md in vxlan_xmit_one() If a VXLAN device is configured with both VXLAN_F_COLLECT_METADATA and VXLAN_F_GBP, and a packet is transmitted through it using an external ip_tunnel_info that lacks the IP_TUNNEL_VXLAN_OPT_BIT flag, md is left pointing to the uninitialized _md stack variable: if (test_bit(IP_TUNNEL_VXLAN_OPT_BIT, info->key.tun_flags)) { if (info->options_len < sizeof(*md)) goto drop; md = ip_tunnel_info_opts(info); } Because IP_TUNNEL_VXLAN_OPT_BIT is not set, md is not updated and remains pointing to _md. Later, vxlan_build_skb() is called with md, which eventually calls vxlan_build_gbp_hdr(): if (vxflags & VXLAN_F_GBP) vxlan_build_gbp_hdr(vxh, md); Inside vxlan_build_gbp_hdr(), md->gbp is read: if (!md->gbp) return; gbp = (struct vxlanhdr_gbp *)vxh; ... if (md->gbp & VXLAN_GBP_DONT_LEARN) gbp->dont_learn = 1; If the stack contains garbage, this causes: 1) VXLAN_HF_GBP flag to be spuriously set in the VXLAN header. 2) gbp->dont_learn and gbp->policy_applied to be set from stack bits. 3) gbp->policy_id to receive 16 bits of uninitialized kernel stack data, leaking it onto the wire. Fix this by zero-initializing _md. If IP_TUNNEL_VXLAN_OPT_BIT is not present, md->gbp remains 0, and vxlan_build_gbp_hdr() returns early without modifying the VXLAN header. The Linux kernel CVE team has assigned CVE-2026-97965 to this issue. Affected and fixed versions =========================== Issue introduced in 4.3 with commit ee122c79d4227f6ec642157834b6a90fcffa4382 and fixed in 6.12.111 with commit 0d13b5a413bffc8718b3821b78537ccc6596c233 Issue introduced in 4.3 with commit ee122c79d4227f6ec642157834b6a90fcffa4382 and fixed in 6.18.53 with commit bfb74c48ac2d31476d5e09cf9658844508d2608a Issue introduced in 4.3 with commit ee122c79d4227f6ec642157834b6a90fcffa4382 and fixed in 7.2.7 with commit 081f22177d9d12b1e381b787f203cd5f47508187 Issue introduced in 4.3 with commit ee122c79d4227f6ec642157834b6a90fcffa4382 and fixed in 7.3-rc3 with commit be83178bfc44588f6e3adb827ed874c683193466 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-2026-97965 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: drivers/net/vxlan/vxlan_core.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/0d13b5a413bffc8718b3821b78537ccc6596c233 https://git.kernel.org/stable/c/bfb74c48ac2d31476d5e09cf9658844508d2608a https://git.kernel.org/stable/c/081f22177d9d12b1e381b787f203cd5f47508187 https://git.kernel.org/stable/c/be83178bfc44588f6e3adb827ed874c683193466