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 CE8BC33ADB1 for ; Thu, 17 Sep 2026 16:15:33 +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=1789661735; cv=none; b=sfBCaC8ujajuIgKDWt6u73/liNIylVrzI/UBS8jr54W7oh5q4HfjO9fWNIZuLlDKV/zrP+SfLotkqRJNaRt2INAZhUSzhewAkVv6D+0muSv9/rbSRt+NI66DI6o5w+9sn+XnmbL7kLv3BzX32UlFyWcTZFgUjLg3CykM0jumkj0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789661735; c=relaxed/simple; bh=re9n6jrbCPJEMbDu4oRAcqln17URXKGiYYQEFgxELKk=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=Mg2PGhrhy4c5vHURjfC95t2OCB6ycI4CR/mfHsDeHV8tgadf2jKZJmRfZWKU+SoaY9N0ZPFSfZTznwrKAwxpXF3lby0h6Fnubs7DS3sl4+T0pwqmPHxjnZIpLvVQH2h9TMBPUNX/FAeJq68EhV9oYh+HhEWFrlFEdu7pu0CNPQI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ckmW/tTy; 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="ckmW/tTy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id ED8C51F000FF; Thu, 17 Sep 2026 16:15:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789661733; bh=n6l/w5oMLGpXOOACW/Y/VQwBLZlYRAsNenwRlltjpPI=; h=From:To:Cc:Subject:Date:Reply-To; b=ckmW/tTyNqNBljAnqEoGVLA6LzxnmrrexeOBG8bI4ycTsnZ5rfdHDpD2cUR4K9eo5 5NEtl5/8WFfYSBO0Es8/qFSuXt/wY7GG6rGiOfhWhjEdVthVOIS+GZB2t40A2NhJmB 1lbnDzE8DFAVZUzkThmIclx6DtfxTR+d6mcuAdmg= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-90117: ntfs: validate usa_ofs before preserving the update sequence number Date: Thu, 17 Sep 2026 17:09:07 +0100 Message-ID: <2026091716-CVE-2026-90117-ece5@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=2813; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=R+XS8prvQ91U5POH9+18osIYkCXNwyTWzZS3zTyOEFo=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlrBAr+W0omTf5oLnlI6b3BqT3r3nhe/Vq+0Tg5ek+90 v2G1YJrO2JZGASZGGTFFFm+bOM5ur/ikKKXoe1pmDmsTCBDGLg4BWAitq0MC6ZPuHvpm27t/V2W 62dubJOY6i76ag3DPD2Zb4Vc93cZ767tFdg+QSqDu31RKQA= 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: ntfs: validate usa_ofs before preserving the update sequence number When ntfs_mft_record_alloc() reuses a free mft record it reads the old update sequence number straight from the on-disk record: usn = *(__le16 *)((u8 *)m + le16_to_cpu(m->usa_ofs)); Here m points into the raw $MFT page-cache folio, which still holds unvalidated, MST-protected bytes: the folio is read by a plain iomap_read_folio() and neither post_read_mst_fixup() nor ntfs_mft_record_check() has run on it (both work on private copies). m->usa_ofs is therefore an untrusted u16, and a corrupted record can put it past the end of the record so the two-byte read lands outside the folio. Reading such a record while creating a file gives, under KASAN: BUG: KASAN: use-after-free in ntfs_mft_record_alloc+... Read of size 2 at addr ... ntfs_mft_record_alloc -> __ntfs_create -> ntfs_create -> path_openat Only preserve the old update sequence number when usa_ofs is even and in range, mirroring the check ntfs_mft_record_check() already applies; otherwise leave usn zero, which the existing restore below skips. The Linux kernel CVE team has assigned CVE-2026-90117 to this issue. Affected and fixed versions =========================== Issue introduced in 7.1 with commit 495e90fa334828d4119061e2726af51d0a0fb4ed and fixed in 7.2.6 with commit ea5a3c30710710c1dc5e483d3313309ec2e868f7 Issue introduced in 7.1 with commit 495e90fa334828d4119061e2726af51d0a0fb4ed and fixed in 7.3-rc1 with commit 81684340963da2e898eabb8c1e274433d9375bc6 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-2026-90117 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: fs/ntfs/mft.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/ea5a3c30710710c1dc5e483d3313309ec2e868f7 https://git.kernel.org/stable/c/81684340963da2e898eabb8c1e274433d9375bc6