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 5918A4EA393 for ; Fri, 4 Sep 2026 15:20:54 +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=1788535255; cv=none; b=oLlaCQ0yvblWbuCbq4Nz0h2o8Bwe7EhfvtmfWPXcGWYO/nTboPVHmCA8XF5z297ceTpI9yzlMRi6Niw8QXyRLVBfxmZrKkQ+8fRgD2qoF4j1kQQXkS2c6ATlGE2coUGX0Zh9BsRrsuodzjXTm7SWJ29VBC7pAiAMej/kh91ydWM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788535255; c=relaxed/simple; bh=3CHfIgCnn77DEsv3xMVfIeuLDnPUYoJFk8KwpNSniTY=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=o79bb1Nb+qASlLiPkfHVSl89riKHFjBDdgjOqsMFmLO/TV4wC/vcZ/nEc9AAI+6VTPpsBZmh0McVM/qN4sggh1rOhn6dIAjY1AV8fM2os8WiNvK/LiLwOq1Ek555+FyNiylc5h37BgtgxDY3KUNs13UruOe4ZNUcksR3N+H3pRc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=G5x3thrZ; 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="G5x3thrZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6EE1D1F00A3D; Fri, 4 Sep 2026 15:20:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788535254; bh=V9hHp1cey58PlmaD5V+F0eN1KmtcP/uJtI2maIkOlew=; h=From:To:Cc:Subject:Date:Reply-To; b=G5x3thrZoFxl6YU497J+d0CuEMiwuR6FIj2J7MwlMzFithVOsrANk+0E0mOQSxwB7 NT9T1+EZBZ3K8PXl574LX+MmYGyWrBK4S+BOhEU6/OeJflhi3HMQDHwdlqseClz0dO IoqIi4Z154AsHwjiPgWZ7TQvtRw9gaN+lxeywO2Y= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-80800: nfc: llcp: bound the connect_sn TLV walk to the skb Date: Fri, 4 Sep 2026 17:11:39 +0200 Message-ID: <2026090408-CVE-2026-80800-5b21@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=5035; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=sznkew1KF4O+3THLGQ2f/qMG/pH3aqEwki7jgOuqWF4=; b=owGbwMvMwCRo6H6F97bub03G02pJDFmz7vd8k2SWe35pRWBYxtRY39ZbM+5fll+14AV/qvjGf VGPOG2LOmJZGASZGGTFFFm+bOM5ur/ikKKXoe1pmDmsTCBDGLg4BWAitpMZ5oeruLvsnjNzWf07 pSqVHoEJp/aH8DPMZvk663S3oL3gt79pft2uGxuWFfH4AwA= 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: nfc: llcp: bound the connect_sn TLV walk to the skb Commit 27256cdb290e ("nfc: llcp: bound SNL TLV parsing to the skb and add length checks") fixed the unbounded TLV walk in nfc_llcp_recv_snl(), and commit d8bd2dedbde5 ("nfc: llcp: fix OOB read and u8 offset wrap in TLV parsers") subsequently bounded nfc_llcp_parse_gb_tlv() and nfc_llcp_parse_connection_tlv(). One sibling parser sharing the same pattern remains unbounded: nfc_llcp_connect_sn(). nfc_llcp_connect_sn() walks a TLV list, reading a two-byte header (type, length) followed by length bytes of value, without checking that the two header bytes or the declared length stay within the buffer. It returns a pointer to a service name of up to 255 bytes that may point past the end of the skb; it is subsequently consumed by memcmp() in nfc_llcp_sock_from_sn(). In addition tlv_array_len was computed as "skb->len - LLCP_HEADER_SIZE" in size_t, so a CONNECT/CC frame shorter than the LLCP header underflows to a huge length and the walk runs far past the buffer. nfc_llcp_connect_sn() is reachable from nfc_llcp_recv_connect() and nfc_llcp_recv_cc(), i.e. from received CONNECT and CC PDUs. A nearby NFC device can reach this without authentication; LLCP link activation happens automatically after NFC-DEP, and the nfc_llcp_rx_skb() dispatcher applies no minimum-length guard. Walk the TLV list by pointer, bounded by skb_tail_pointer(skb), and validate each declared length before use, matching the approach already used for nfc_llcp_recv_snl(). Starting the walk at &skb->data[LLCP_HEADER_SIZE] against the tail pointer also removes the size_t underflow for short frames. Found by 0sec automated security-research tooling (https://0sec.ai). The Linux kernel CVE team has assigned CVE-2026-80800 to this issue. Affected and fixed versions =========================== Issue introduced in 3.3 with commit d646960f7986fefb460a2b062d5ccc8ccfeacc3a and fixed in 5.10.267 with commit b2ebdfe3d5b76e91f267a61cbc3f9a0e3f77071e Issue introduced in 3.3 with commit d646960f7986fefb460a2b062d5ccc8ccfeacc3a and fixed in 5.15.218 with commit e18d044bab6d3d0280639098c3fe6621692cbfe2 Issue introduced in 3.3 with commit d646960f7986fefb460a2b062d5ccc8ccfeacc3a and fixed in 6.1.185 with commit 65a0ec7783b06068dda6745dd689bf4a91ee64aa Issue introduced in 3.3 with commit d646960f7986fefb460a2b062d5ccc8ccfeacc3a and fixed in 6.6.154 with commit 1964addc8dd535a05d5d3b55b4d1ac19ae31aa65 Issue introduced in 3.3 with commit d646960f7986fefb460a2b062d5ccc8ccfeacc3a and fixed in 6.12.106 with commit 389986fd79e4d43f971a03b512645a1bb63c982f Issue introduced in 3.3 with commit d646960f7986fefb460a2b062d5ccc8ccfeacc3a and fixed in 6.18.47 with commit e87527b506c40db9af528714b7b1240918eb80fc Issue introduced in 3.3 with commit d646960f7986fefb460a2b062d5ccc8ccfeacc3a and fixed in 7.1.11 with commit 22e5177ba1196a0b272a6a46c2575eb940a939c4 Issue introduced in 3.3 with commit d646960f7986fefb460a2b062d5ccc8ccfeacc3a and fixed in 7.2.1 with commit 0cfbdb0e13ab5b0765d77f96af67eb879cbc9736 Issue introduced in 3.3 with commit d646960f7986fefb460a2b062d5ccc8ccfeacc3a and fixed in 7.3-rc1 with commit 55c68ac93e7dacc0f5f608b9c39dd4ff48cf28e8 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-2026-80800 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/nfc/llcp_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/b2ebdfe3d5b76e91f267a61cbc3f9a0e3f77071e https://git.kernel.org/stable/c/e18d044bab6d3d0280639098c3fe6621692cbfe2 https://git.kernel.org/stable/c/65a0ec7783b06068dda6745dd689bf4a91ee64aa https://git.kernel.org/stable/c/1964addc8dd535a05d5d3b55b4d1ac19ae31aa65 https://git.kernel.org/stable/c/389986fd79e4d43f971a03b512645a1bb63c982f https://git.kernel.org/stable/c/e87527b506c40db9af528714b7b1240918eb80fc https://git.kernel.org/stable/c/22e5177ba1196a0b272a6a46c2575eb940a939c4 https://git.kernel.org/stable/c/0cfbdb0e13ab5b0765d77f96af67eb879cbc9736 https://git.kernel.org/stable/c/55c68ac93e7dacc0f5f608b9c39dd4ff48cf28e8