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 85FD258B6BA for ; Fri, 11 Sep 2026 19:57:47 +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=1789156678; cv=none; b=fSWtqKW8aWZvktkG8frbxysaY962etFtLNJbHs2zTVmX/1RaWP0wr6zvd7eqAFHNxYS/glT5vWKqWWk/4fRTJDc5u7HvA7vBape8UvBNZcHnzixTYArptihR40rDv/RwKcJYyhYDbPETNt4yHISe3gO9otBHxQ5cF4k0l9BAngc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789156678; c=relaxed/simple; bh=gPON6ThV/O7WfEWBrv4DTI7a30acA7zRt3tCEe5Wkkw=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=I5t57cVeaUCIVfjkd0vvzjVcuxcCueKpNFtN+2X9CQFUtczCUdk8i1wSRshLzzLR29mUyFWc05/VMeZVNrxkhj0ZY6LE+bnDBB6YbaUv6EtZvcgOcoFls6yzg1IP71vQD2dpQY3h9NTweGGRjLSzAh1A/6Oe1AmEGhcFS7g9sjk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=hMNnzQp4; 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="hMNnzQp4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 60C981F000FF; Fri, 11 Sep 2026 19:57:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789156663; bh=HbfH0EMUiqUt30SqsDVH2r2f9qB/lPmwKyw7B5UUwuQ=; h=From:To:Cc:Subject:Date:Reply-To; b=hMNnzQp4b9v7GQIUUsUBpa13tr0mG5cwVxuIkKHTrczNdAWTwh9ReD2JTjAQInnNe 1CN3BZxJikv3gRcQbjXembppUvQwXpZmSfSBbEHmmWsFivjhNg2Gew7yF8eTavVvyw +vd2EqxWLnDQK6FK+H9sLwmNplTyIzxCyJGSpM3A= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89558: md/raid10: fix still_degraded being inverted in raid10_sync_request() Date: Fri, 11 Sep 2026 21:44:07 +0200 Message-ID: <2026091123-CVE-2026-89558-2b69@gregkh> X-Mailer: git-send-email 2.55.0 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=3441; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=GNRuOEhrwEMgSkjTsC3AVbjq9LaNB8ZvB9GyE6YanlI=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlLIpOV/l4qeLdpka344tXfql5a73z+y+3kRtuX2p4tx Yfjfvqld8SyMAgyMciKKbJ82cZzdH/FIUUvQ9vTMHNYmUCGMHBxCsBEPuYzLJhff1ZDriHsnx6H +88Zv8rqJq4S2sWwoKN08+r332eerVBe+/pV1SWNiqxDzQA= 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: md/raid10: fix still_degraded being inverted in raid10_sync_request() Commit fe6a19d40ceb ("md/md-bitmap: merge md_bitmap_start_sync() into bitmap_operations") converted still_degraded from int to bool, but inverted the assignment in the loop that checks whether the array will still be degraded after the current device is recovered: "still_degraded = 1" became "still_degraded = false". As a result, recovering a device while another mirror is still missing calls md_bitmap_start_sync() with degraded == false, which clears bitmap bits that the still-missing device needs. When that device is re-added, its bitmap-based recovery finds the bits already cleared and skips every region written while the array was degraded, so it is marked In_sync while holding stale data: silent corruption. Reproducer (raid10 near=2, 4 disks, internal bitmap): - fail and remove one disk of each mirror pair - write to the degraded array - re-add both disks and let recovery finish - "check" reports mismatch_cnt=262272 after 256 MiB of degraded writes and file contents differ; the second disk's "recovery" completes in milliseconds because everything is skipped The same conversion in raid1 got it right (still_degraded = true). Restore the correct value. The Linux kernel CVE team has assigned CVE-2026-89558 to this issue. Affected and fixed versions =========================== Issue introduced in 6.12 with commit fe6a19d40ceb44281905485f56dda715e3214e0e and fixed in 6.12.109 with commit 9bb8da6ecb330a5b1ac9b96f1e55f134a7aef1d4 Issue introduced in 6.12 with commit fe6a19d40ceb44281905485f56dda715e3214e0e and fixed in 6.18.50 with commit 0efabe6229dc683dbf6eeebd0f9fddc7971ed420 Issue introduced in 6.12 with commit fe6a19d40ceb44281905485f56dda715e3214e0e and fixed in 7.2.4 with commit 00449d752bee9c8787f42ea1bf533a9fb17f9b6b Issue introduced in 6.12 with commit fe6a19d40ceb44281905485f56dda715e3214e0e and fixed in 7.3-rc1 with commit 47f1441b281decde6954a2fa82b4131637d685ac 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-2026-89558 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/md/raid10.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/9bb8da6ecb330a5b1ac9b96f1e55f134a7aef1d4 https://git.kernel.org/stable/c/0efabe6229dc683dbf6eeebd0f9fddc7971ed420 https://git.kernel.org/stable/c/00449d752bee9c8787f42ea1bf533a9fb17f9b6b https://git.kernel.org/stable/c/47f1441b281decde6954a2fa82b4131637d685ac