From patchwork Wed Aug 12 07:28:39 2026 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Junjie Cao X-Patchwork-Id: 94986 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 D8852C5B567 for ; Wed, 12 Aug 2026 05:32:00 +0000 (UTC) Received: from out-179.mta0.migadu.com (out-179.mta0.migadu.com [91.218.175.179]) by mx.groups.io with SMTP id smtpd.msgproc01-g2.1531.1786512716552142226 for ; Tue, 11 Aug 2026 22:31:56 -0700 Authentication-Results: mx.groups.io; dkim=fail reason="dkim: body hash did not verify" header.i=@linux.dev header.s=key1 header.b=aBkVNGM2; spf=pass (domain: linux.dev, ip: 91.218.175.179, 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=1786512714; 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=xNAXrbYx7bdElRyOIEnNH3bfS48FtYGtJQBYXY6bDsc=; b=aBkVNGM2CiYzZr0eR5kmptri5rz+TGDOSrdRpftQEiWWWjo8suoVtUx+5Cv+yjJeBTyQE1 cyWqflekIc3O/kyHe1dmkGjrW0t+EQyrqqVtCvsNKy3VCqI3J7vZoWF+65e7nc1a/Y2IjH cpHf3SzntHDFCiWQtwjuLvQsI7tl0fQ= From: Junjie Cao To: openembedded-core@lists.openembedded.org Cc: paul@pbarker.dev Subject: [OE-core][PATCH v3 6/9] cve-exclusions: set status for CVE-2022-4543 Date: Wed, 12 Aug 2026 02:28:39 -0500 Message-ID: <20260812072842.1176341-7-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 05:32:00 -0000 X-Groupsio-URL: https://lists.openembedded.org/g/openembedded-core/message/243231 KPTI clones the kernel entry text into the user page tables at its KASLR-slid address and, on CPUs with PGE, sets the global bit on those PTEs. The mapping survives the CR3 write on kernel exit, and a local attacker can time prefetch instructions across the kernel range to recover the KASLR base in well under a second. Disclosure and write-up: https://www.openwall.com/lists/oss-security/2022/12/16/3 https://www.willsroot.io/2022/12/entrybleed.html The disclosure states that after discussion with security@kernel.org and linux-distros "a fix for this is currently not available", and none has appeared since; arch/x86/mm/pti.c still clones the entry text and sets _PAGE_GLOBAL on the cloned PTEs. This is an unfixed issue, not a stated wontfix - Debian notes "Ignored upstream and KASLR is not expected to be resistant to local attacks", Ubuntu has it deferred since 2023-01-10: https://security-tracker.debian.org/tracker/CVE-2022-4543 https://ubuntu.com/security/CVE-2022-4543 97e3d26b5e5f ("x86/mm: Randomize per-cpu entry area", v6.2) randomizes the separate cpu_entry_area; it predates this disclosure and does not change the offset of entry_SYSCALL_64 from the KASLR base. CC: Paul Barker AI-Generated: Uses Claude (claude-opus-5) Signed-off-by: Junjie Cao --- v3: - use "unpatched" instead of "upstream-wontfix": the security-team discussion produced no clear wontfix decision v2: https://lore.kernel.org/openembedded-core/20260803084827.1348810-1-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 b08eaa1..a909aef 100644 --- a/meta/recipes-kernel/linux/cve-exclusion.inc +++ b/meta/recipes-kernel/linux/cve-exclusion.inc @@ -229,3 +229,11 @@ was never substantiated and was closed as not-a-bug by Red Hat, SUSE and Debian" # Fix https://git.kernel.org/linus/d860d1faa6b2ce3becfdb8b0c2b048ad31800061 # Fix https://git.kernel.org/linus/da9c9c877597170b929a6121a68dcd3dd9a80f45 CVE_STATUS[CVE-2022-1247] = "fixed-version: Fixed from version 6.17" + +# "EntryBleed": KPTI maps the entry text into the user page tables with +# the global bit set, leaking the KASLR base by prefetch timing. Discussed +# with the kernel security team; no fix, KASLR is not treated as a boundary +# against local attackers. Distinct from CVE-2023-3640 (cpu_entry_area). +# https://www.willsroot.io/2022/12/entrybleed.html +CVE_STATUS[CVE-2022-4543] = "unpatched: no upstream fix, KASLR is not \ +treated as a defence against local attackers"