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 787985867FC for ; Fri, 11 Sep 2026 19:58:37 +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=1789156724; cv=none; b=KzKoc9SsOs4QUknQ/guPxepkXXcC3B68rK2DAa5a0Yd2+7v2EprNvxsPtYAOG8Kn2iSGQ8187F6EI5gzw309R00lnWrbhoPwbVuz4Luj+fdils9bdYNGHDSnyzUYsLAtkE+8FYf21tG/DjOgURzRf1AA30YiFXiesn6A1PrbMLc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789156724; c=relaxed/simple; bh=oBDzGhTGmtnSuwL9s3HwXxM9548mmFwZ8U6fl6RkMAQ=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=lYkgoVP9rY46qLTwz+b6VAGgjcOJ9CC17cNlnvle2I32Y0h2GECpSIrWTT4f7D8yEnyB7DY7oi3d5gdGaPexmlV/o+cTd0WabcJuy6EmEf1zk7bX1vl55oLTKANS7MWVNd0PLoP+SvKbbv7GuNn7M0yPAuc4cFmQl8V83oOBF3k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=mS8yFvVH; 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="mS8yFvVH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3AD811F00898; Fri, 11 Sep 2026 19:58:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789156708; bh=YdgdWUlcFfchgGCtw5JreBq9+bG9N2TaLeb1zU5pMMo=; h=From:To:Cc:Subject:Date:Reply-To; b=mS8yFvVHf/8dhsITJKIkCH/vFVIbwCvfjJXcX9fA4MSoxVRGput6pV5T3nlxj3icV Sf1bUVbGImdQCCpxZXOImgJf1TKikFhGs5Ytl8nIHElwC5bdiRs4+D+cONbcIsqrAi 4QBLuMr0bOXEmfg/dQbuW5ajR1wMHkS+8uaJLqQY= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89607: ecryptfs: reject oversized encrypted_key_size in parse_tag_3_packet Date: Fri, 11 Sep 2026 21:44:56 +0200 Message-ID: <2026091134-CVE-2026-89607-3077@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=3669; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=X51X9Ya/RPYSKA3mYVqor+tctTLMD2rScOUFQeRx/Nc=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlLIvPuldlw2jIdNwxZKCi/jC9ct9Tfx41N45z+OkdH3 ptHb6V0xLIwCDIxyIopsnzZxnN0f8UhRS9D29Mwc1iZQIYwcHEKwEQUmRnmGVifODpXTuuVqXGd 0jLVC//yPywJYpif/U//woqyG4dXy8S3T424W/JCtSUMAA== 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: ecryptfs: reject oversized encrypted_key_size in parse_tag_3_packet parse_tag_3_packet() set encrypted_key_size from the Tag 3 packet body without bounding it against ECRYPTFS_MAX_KEY_BYTES (64). When encrypted_key_size > 64, decrypt_passphrase_encrypted_session_key() sets decrypted_key_size = encrypted_key_size and performs two out-of-bounds writes: 1. crypto_skcipher_decrypt() writes encrypted_key_size bytes into decrypted_key[64] via scatterlist, overflowing into the parent ecryptfs_auth_tok struct. 2. memcpy(crypt_stat->key, decrypted_key, decrypted_key_size) writes into crypt_stat->key[64], corrupting root_iv, keysig_list, and mutexes in ecryptfs_crypt_stat. Only AES-192 (cipher code 0x08) enables this because it sets crypt_stat->key_size = 24 independently of encrypted_key_size, allowing crypto_skcipher_setkey() to succeed while encrypted_key_size exceeds ECRYPTFS_MAX_KEY_BYTES. The PKI decryption path (parse_tag_65_packet) already validates decrypted_key_size <= ECRYPTFS_MAX_KEY_BYTES; the passphrase path omits this check. Bound encrypted_key_size against ECRYPTFS_MAX_KEY_BYTES (64) rather than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES (512). The 64-byte limit also protects the 512-byte encrypted_key[] buffer, so the former 512-byte check is removed as redundant. [tyhicks: Adjust the code comment to refer to macros representing the buffer sizes rather than mentioning the buffer size values since they may change in the future] The Linux kernel CVE team has assigned CVE-2026-89607 to this issue. Affected and fixed versions =========================== Issue introduced in 2.6.19 with commit 237fead619984cc48818fe12ee0ceada3f55b012 and fixed in 6.12.109 with commit ccd13eff0e7356d2aa28b127b577e4e5ad4563f5 Issue introduced in 2.6.19 with commit 237fead619984cc48818fe12ee0ceada3f55b012 and fixed in 6.18.50 with commit 14cb36a500a5a3afbc955dbf69dabc565f1a3b26 Issue introduced in 2.6.19 with commit 237fead619984cc48818fe12ee0ceada3f55b012 and fixed in 7.2.4 with commit a419c9ebfc9a40ee56aaad6dc68bfd67d400817b Issue introduced in 2.6.19 with commit 237fead619984cc48818fe12ee0ceada3f55b012 and fixed in 7.3-rc1 with commit 5babe9c177c364521e3e682b949c5a8c47f4a441 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-2026-89607 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: fs/ecryptfs/keystore.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/ccd13eff0e7356d2aa28b127b577e4e5ad4563f5 https://git.kernel.org/stable/c/14cb36a500a5a3afbc955dbf69dabc565f1a3b26 https://git.kernel.org/stable/c/a419c9ebfc9a40ee56aaad6dc68bfd67d400817b https://git.kernel.org/stable/c/5babe9c177c364521e3e682b949c5a8c47f4a441