From patchwork Wed Aug 12 07:28:42 2026 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Junjie Cao X-Patchwork-Id: 94989 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 D900EC5B567 for ; Wed, 12 Aug 2026 05:33:20 +0000 (UTC) Received: from out-182.mta1.migadu.com (out-182.mta1.migadu.com [37.59.57.117]) by mx.groups.io with SMTP id smtpd.msgproc02-g2.1502.1786512798502560219 for ; Tue, 11 Aug 2026 22:33:18 -0700 Authentication-Results: mx.groups.io; dkim=fail reason="dkim: body hash did not verify" header.i=@linux.dev header.s=key1 header.b=N4f/PhB3; spf=pass (domain: linux.dev, ip: 37.59.57.117, 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=1786512796; 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=JcyfdIorAxCqa+NrHLQeR+0arq9JpIWM1Vab1fp751o=; b=N4f/PhB3BfRx28Tp+bkIIimy1gu1NYVkjvimJ6oxWgQqeHX+SKwdqpDWPZ8BCM5dJbZzpO 9Oj/RQj4+xPsLTWk4d1SWz1Iiz/uSwQ950FQlyMBguBFOOPiNq1trer6MX7pW6m4Px+KU6 BWJwvCdgxd4vht1+j1MjlKBTEXoTaCA= From: Junjie Cao To: openembedded-core@lists.openembedded.org Cc: paul@pbarker.dev Subject: [OE-core][PATCH v3 9/9] cve-exclusions: set status for CVE-2023-6240 Date: Wed, 12 Aug 2026 02:28:42 -0500 Message-ID: <20260812072842.1176341-10-junjie.cao@linux.dev> In-Reply-To: <20260812072842.1176341-1-junjie.cao@linux.dev> References: <20260812072842.1176341-1-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 ; Wed, 12 Aug 2026 05:33:20 -0000 X-Groupsio-URL: https://lists.openembedded.org/g/openembedded-core/message/243234 "Marvin" is Hubert Kario's Bleichenbacher-style timing oracle research: 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 or implicit-rejection fallback in the tree. Red Hat classifies it CWE-203 and has shipped fixes only in RHEL errata (RHSA-2024:2758, RHSA-2024:3618 and others); the bugzilla is still NEW. Ubuntu records it unfixed upstream as of 2024-08-24 and Debian lists src:linux vulnerable in all suites: https://access.redhat.com/security/cve/CVE-2023-6240 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. CC: Paul Barker AI-Generated: Uses Claude (claude-opus-5) Signed-off-by: Junjie Cao --- v3: - drop the Marvell/s390 aside and the unrelated e8829ef1f73f paragraph flagged in review as LLM confusion artifacts v2: https://lore.kernel.org/openembedded-core/20260803084827.1348810-1-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 35e0a66..637f8b6 100644 --- a/meta/recipes-kernel/linux/cve-exclusion.inc +++ b/meta/recipes-kernel/linux/cve-exclusion.inc @@ -252,3 +252,10 @@ affected fs/jfs txEnd()/lmLogClose() unmount race is unchanged" # 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. Still present in +# mainline; fixed only in RHEL errata. +# 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"