From patchwork Mon Aug 3 08:48:27 2026 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Junjie Cao X-Patchwork-Id: 94295 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 371A2C55175 for ; Mon, 3 Aug 2026 08:51:08 +0000 (UTC) Received: from out-189.mta0.migadu.com (out-189.mta0.migadu.com [91.218.175.189]) by mx.groups.io with SMTP id smtpd.msgproc02-g2.39099.1785747059919858781 for ; Mon, 03 Aug 2026 01:51:00 -0700 Authentication-Results: mx.groups.io; dkim=fail reason="dkim: body hash did not verify" header.i=@linux.dev header.s=key1 header.b=BxcvSbVo; spf=pass (domain: linux.dev, ip: 91.218.175.189, mailfrom: junjie.cao@linux.dev) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1785747057; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=OJQPS/QikPsn+CVxX88CQ4ElnIPEhXE59yy0y5khDcw=; b=BxcvSbVoK+JjzWCUIzjR9e9/VopwUY4Ni0DwpQ0tn/i16IFAsNyX7zf8T/7HwW+hHvv9Xh Bz7gvCJlYlkhI/fjIU45TwnDEoAnM0+pACE1xKpTQXdpKhDccgbxFBn4Y8u2IbVUfbk1qk RjEUMk+mhlfMO45UVelqbkIBJR4pbGI= From: Junjie Cao To: openembedded-core@lists.openembedded.org Cc: paul@pbarker.dev, randy.macleod@windriver.com, Venkata.Navuduri@windriver.com Subject: [OE-core][PATCH v2 10/10] cve-exclusion: set status for CVE-2023-6240 Date: Mon, 3 Aug 2026 01:48:27 -0700 Message-ID: <20260803084827.1348810-11-junjie.cao@linux.dev> In-Reply-To: <20260803084827.1348810-1-junjie.cao@linux.dev> References: <20260803084827.1348810-1-junjie.cao@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT List-Id: X-Webhook-Received: from 45-33-107-173.ip.linodeusercontent.com [45.33.107.173] by aws-us-west-2-korg-lkml-1.web.codeaurora.org with HTTPS for ; Mon, 03 Aug 2026 08:51:08 -0000 X-Groupsio-URL: https://lists.openembedded.org/g/openembedded-core/message/242636 "Marvin" is Hubert Kario's Bleichenbacher-style timing oracle research, not a Marvell or s390 issue as some data sets suggest: https://people.redhat.com/~hkario/marvin/ The affected code is the generic software RSA PKCS#1 v1.5 unpadding in crypto/rsa-pkcs1pad.c. pkcs1pad_decrypt_complete() has three secret-dependent early exits (leading zero byte, block type, minimum padding length) and a loop whose trip count depends on the position of the separator, so the time taken reveals padding validity. There is no constant-time unpadding and no implicit-rejection fallback in the tree, and no commit touching that file addresses decryption timing. Red Hat classifies it CWE-203 and has shipped fixes only in RHEL errata (RHSA-2024:2758 for 9.4, RHSA-2024:3618 for 8.10 and others); the corresponding bugzilla is still NEW: https://access.redhat.com/security/cve/CVE-2023-6240 Ubuntu records "appears unfixed in upstream as of 2024.08.24" and Debian lists src:linux as vulnerable in all suites: https://ubuntu.com/security/CVE-2023-6240 https://security-tracker.debian.org/tracker/CVE-2023-6240 Practical exposure is narrow: kernel PKCS#1 v1.5 use is dominated by signature verification rather than decryption, and an attacker needs a service driving KEYCTL_PKEY_DECRYPT with a long-lived key. The leaky primitive is nevertheless reachable. e8829ef1f73f ("crypto: rsa - restrict plaintext/ciphertext values more", v6.9) is unrelated: it enforces SP800-56B value restrictions and is not a timing fix. CC: Paul Barker AI-Generated: Uses Claude (claude-opus-5) Signed-off-by: Junjie Cao --- changes in v2: - split out of the single combined patch, one CVE per patch as requested - added primary source links (disclosures, distribution trackers, mailing list threads, upstream commits) to every commit message - added the three CVEs with no upstream fix as "unpatched" entries instead of leaving them undocumented - disclosed AI assistance per the contributor guide v1: https://lore.kernel.org/openembedded-core/20260802143444.1178575-1-junjie.cao@linux.dev/ meta/recipes-kernel/linux/cve-exclusion.inc | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/meta/recipes-kernel/linux/cve-exclusion.inc b/meta/recipes-kernel/linux/cve-exclusion.inc index 506d3705..4ac5e343 100644 --- a/meta/recipes-kernel/linux/cve-exclusion.inc +++ b/meta/recipes-kernel/linux/cve-exclusion.inc @@ -252,3 +252,10 @@ CVE_STATUS[CVE-2023-4010] = "fixed-version: Fixed from version 6.18" # https://lore.kernel.org/linux-nvme/20231016060519.231880-1-joshi.k@samsung.com/ CVE_STATUS[CVE-2023-6238] = "unpatched: the proposed fix was applied to \ nvme-6.6 and then reverted, no upstream fix has landed since" + +# "Marvin": the PKCS#1 v1.5 unpadding in crypto/rsa-pkcs1pad.c branches on +# secret-derived data, leaking padding validity by timing. Not a Marvell or +# s390 issue despite some data sets. Fixed only in RHEL downstream. +# https://people.redhat.com/~hkario/marvin/ +CVE_STATUS[CVE-2023-6240] = "unpatched: Bleichenbacher-style timing oracle in \ +crypto/rsa-pkcs1pad.c is still present in mainline, fixed only downstream in RHEL"