From patchwork Mon Aug 24 04:21:18 2026 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Junjie Cao X-Patchwork-Id: 96119 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 E28D1C5DF8C for ; Mon, 24 Aug 2026 02:23:02 +0000 (UTC) Received: from mta1.migadu.com (mta1.migadu.com [95.215.58.236]) by mx.groups.io with SMTP id smtpd.msgproc01-g2.8451.1787538176580053917 for ; Sun, 23 Aug 2026 19:22:56 -0700 Authentication-Results: mx.groups.io; dkim=pass header.i=@linux.dev header.s=key1 header.b=oF7z9yh0; spf=pass (domain: linux.dev, ip: 95.215.58.236, mailfrom: junjie.cao@linux.dev) X-Envelope-To: openembedded-core@lists.openembedded.org DKIM-Signature: a=rsa-sha256; bh=fidx4U7jtJX+oa/JHY2O2XZVSFhB4JydMSGAvpIvV2I=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1787538174; v=1; x=1788142974; b=oF7z9yh0HfGhBcpCakaADxOfm/N86ILZsLKUsZyvPd9bJtCGxs/4sBF2Hqlw9KgkSZ2yaL/d 1pCaqIG8fyptnTXhmA5/Tf7bqcMI+p27AcZsaWpwk6WxCxSIQQIH9naJqJbrCRW2R2AN3V+1tA0 i6NW8nPWC25fC62skBngEw2E= X-Envelope-To: openembedded-core@lists.openembedded.org Received: from localhost (2408:8806:52:f8ea:5de6:8d95:1672:70f3) by smtp.migadu.com with ESMTPS id 2db75e3871ae28aa; Mon, 24 Aug 2026 02:22:54 +0000 X-Mizu-Trace-ID: 2db75e3871ae28aa X-Migadu-Flow: FLOW_OUT From: Junjie Cao To: openembedded-core@lists.openembedded.org Cc: paul@pbarker.dev Subject: [OE-core][PATCH v4 3/8] cve-exclusions: set status for CVE-2021-3864 Date: Sun, 23 Aug 2026 23:21:18 -0500 Message-ID: <20260824042123.1456876-4-junjie.cao@linux.dev> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260824042123.1456876-1-junjie.cao@linux.dev> References: <20260824042123.1456876-1-junjie.cao@linux.dev> MIME-Version: 1.0 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, 24 Aug 2026 02:23:02 -0000 X-Groupsio-URL: https://lists.openembedded.org/g/openembedded-core/message/244049 begin_new_exec() resets dumpability to owner-dumpable whenever the real and effective ids match at exec time. A binary exec'd by a setuid program that has already called setuid(0) therefore becomes dumpable as root, and with a relative core_pattern plus an attacker-controlled working directory the resulting core file can be dropped into a privileged directory such as /etc/logrotate.d. Full report with proof of concept: https://www.openwall.com/lists/oss-security/2021/10/20/2 Two fixes were proposed and neither was merged. Waiman Long's patch was judged "not a particularly effective mitigation" by Eric W. Biederman and the discussion went quiet by early 2022; Wander Lairson Costa's RFC v2 received design feedback and no v3 followed: https://lore.kernel.org/all/20211221021744.864115-1-longman@redhat.com/ https://lore.kernel.org/all/20211228170910.623156-1-wander@redhat.com/ CC: Paul Barker AI-Generated: Uses Claude (claude-opus-5) Signed-off-by: Junjie Cao --- v4: - use the review's comment and status wording; drop the coredump path analysis paragraph - quote Biederman's assessment verbatim v3: https://lore.kernel.org/openembedded-core/20260812072842.1176341-1-junjie.cao@linux.dev/ meta/recipes-kernel/linux/cve-exclusion.inc | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/meta/recipes-kernel/linux/cve-exclusion.inc b/meta/recipes-kernel/linux/cve-exclusion.inc index 36643ccc..36920e2c 100644 --- a/meta/recipes-kernel/linux/cve-exclusion.inc +++ b/meta/recipes-kernel/linux/cve-exclusion.inc @@ -206,3 +206,11 @@ model, no upstream fix" # https://ubuntu.com/security/CVE-2021-3714 CVE_STATUS[CVE-2021-3714] = "unpatched: Timing side channel inherent to Kernel \ Same-page Merging (KSM) page deduplication" + +# Triaged August 2026 - Two fixes proposed upstream but neither was merged, +# attempts to fix seem to have petered out. Unfixed in Debian/Ubuntu. +# https://lore.kernel.org/all/20211221021744.864115-1-longman@redhat.com/ +# https://lore.kernel.org/all/20211228170910.623156-1-wander@redhat.com/ +# https://security-tracker.debian.org/tracker/CVE-2021-3864 +# https://ubuntu.com/security/CVE-2021-3864 +CVE_STATUS[CVE-2021-3864] = "unpatched: Proposed fixes were not merged upstream"