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 5002D3CF66B for ; Wed, 27 May 2026 12:20:45 +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=1779884446; cv=none; b=Zlmc2bdMJB+bsIKJOKwidhjPbHkALxn2M+90wKvKMNfx/0MkcoA58tJtfHcpEJhRys3pJLAZLSU7acB5EmDw0ciEjqgTMWh7vGEJp75tcoXq7JX5zqm8n0znpjFWy3ignFH6Q1HMrAF8/qCgPXy+o3rpy0XJgkbdLTRz2J0dg5U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779884446; c=relaxed/simple; bh=rvmXjJU4mkgio3a6Eg4dGZggeRDGOxc9/VSpEv5u83k=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=HPe8hGQX2gmbi0uyMw+6osWjFCFq2Qedg9HoDbhKgQzMl8JZ3Bs558ojV9gB0hIdJYz83crYuWBWH9zL0IpQdh+7R1qeIQ7VVICVy6y1tf1Q+tJfcIqet48eRKU7eET8jW5vl+RJp1TCBXlTiOYA87Yzdc5A+GzZ7AmZjSli79I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Ogi71HRC; 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="Ogi71HRC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 95B7E1F000E9; Wed, 27 May 2026 12:20:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779884445; bh=VNHdxUXfCQYdXfrbTjmM/t0ufuSnz+U/gUH/S5PXjiA=; h=From:To:Cc:Subject:Date:Reply-To; b=Ogi71HRCqnerHPcw4KnL8DruuL/WCbBX5zgQPyU9GWe2Ha9kPUyMwXMnsX7tJL0PY XJ6AlzEhZxNBLEZ3EAET98djD15rXAa6JAIbCQWusXUcHk+IWH2WFJv+MOwUaSOZLu 7ha4BZaMw0pcW5A/TBdnLJ+v4NtMCLuIEaBFmWCo= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-45865: mctp i2c: initialise event handler read bytes Date: Wed, 27 May 2026 14:18:27 +0200 Message-ID: <2026052711-CVE-2026-45865-87b8@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=2954; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=LdMrPwi1EO95e6lgmGfI7zVzLGsVMdxAxM2CyABv0mU=; b=owGbwMvMwCRo6H6F97bub03G02pJDFliD5lnf5rXmdw79eCfqOTSXz55QcmGQqHb+S6dUZhY6 2gwp8aqI5aFQZCJQVZMkeXLNp6j+ysOKXoZ2p6GmcPKBDKEgYtTACay0oFhwZbzk9ZYv/GqiFoS b5TiOS+j4p+nPcP8PG5WcR45/Yc7NqXq+Ukfdrgf1DgJAA== 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: mctp i2c: initialise event handler read bytes Set a 0xff value for i2c reads of an mctp-i2c device. Otherwise reads will return "val" from the i2c bus driver. For i2c-aspeed and i2c-npcm7xx that is a stack uninitialised u8. Tested with "i2ctransfer -y 1 r10@0x34" where 0x34 is a mctp-i2c instance, now it returns all 0xff. The Linux kernel CVE team has assigned CVE-2026-45865 to this issue. Affected and fixed versions =========================== Issue introduced in 5.18 with commit f5b8abf9fc3dacd7529d363e26fe8230935d65f8 and fixed in 6.1.165 with commit 93e01e837e105299f1c259ef71f6e1ec4fe806e3 Issue introduced in 5.18 with commit f5b8abf9fc3dacd7529d363e26fe8230935d65f8 and fixed in 6.6.128 with commit 11f83253244060b5de5eac787f61ae3f3e559d01 Issue introduced in 5.18 with commit f5b8abf9fc3dacd7529d363e26fe8230935d65f8 and fixed in 6.12.75 with commit fa9861e5c8af7651dddfa8d490aaada17ae33b6c Issue introduced in 5.18 with commit f5b8abf9fc3dacd7529d363e26fe8230935d65f8 and fixed in 6.18.14 with commit 6ff2ebfef75fbc57d937d8fbe738b967edf2d331 Issue introduced in 5.18 with commit f5b8abf9fc3dacd7529d363e26fe8230935d65f8 and fixed in 6.19.4 with commit 1eeedb310229bfee9dd4d992e5bba33fe1378a8f Issue introduced in 5.18 with commit f5b8abf9fc3dacd7529d363e26fe8230935d65f8 and fixed in 7.0 with commit 2a14e91b6d76639dac70ea170f4384c1ee3cb48d 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-2026-45865 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/mctp/mctp-i2c.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/93e01e837e105299f1c259ef71f6e1ec4fe806e3 https://git.kernel.org/stable/c/11f83253244060b5de5eac787f61ae3f3e559d01 https://git.kernel.org/stable/c/fa9861e5c8af7651dddfa8d490aaada17ae33b6c https://git.kernel.org/stable/c/6ff2ebfef75fbc57d937d8fbe738b967edf2d331 https://git.kernel.org/stable/c/1eeedb310229bfee9dd4d992e5bba33fe1378a8f https://git.kernel.org/stable/c/2a14e91b6d76639dac70ea170f4384c1ee3cb48d