From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 D73A23D3CEE; Fri, 24 Apr 2026 13:32:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777037521; cv=none; b=VKM+TiZ0HEJbUh0JYQX3KmTAn8yHSOGRmGhXdzyaLJ+xGzJlQGlp6KOHV2RTHcnl5AFLtPEYPOD+h78i6JEt6G/7BUahOUg//lCgVTyr6S/yP/8p87CvX+XoWhg58iq6YPEjQja4xpuOfx5NdhXgqjj+4AyBjOjxEA11mvYVQdc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777037521; c=relaxed/simple; bh=lUOKdkBzArG51/WyNkYBrcP2zIiJ1jF3ySmsXZob7Fk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=u+PISaZDzcfl8sekzau9/33wIaARLY4552E90gof16LvkE3Gq/fozaWpC4AZ3pBs1rIu+K1Hw3tGVsYtw55zf9lqY8/b+Qw7L5sQhl4zHYNrZJsWs97yIQMpok+KlhLP0MyuQOaz1GmEnKqQASFAWjhE3TDlbHReM9UD6iUOA1o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ZHdX/53t; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ZHdX/53t" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E0C32C2BCB2; Fri, 24 Apr 2026 13:31:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1777037520; bh=lUOKdkBzArG51/WyNkYBrcP2zIiJ1jF3ySmsXZob7Fk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZHdX/53t0MsV86AmzS5/1plDbmcKkiJNXylPZiC6kgjHHZnzrzIYAh4N0oY2v4nWP Awk6Fef7nJL6M/eb3/wkcEvAyPJifdPuCEDBfGaup+rs+UznqnG8b+ju/1RH8YaRGh 6nt1PJjewe5Q/bGGvXOvUOm+vXYwrCjtNhThQ5eo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Konstantin Komarov , stable Subject: [PATCH 7.0 10/42] fs/ntfs3: validate rec->used in journal-replay file record check Date: Fri, 24 Apr 2026 15:30:35 +0200 Message-ID: <20260424132422.610163655@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260424132420.410310336@linuxfoundation.org> References: <20260424132420.410310336@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Greg Kroah-Hartman commit 0ca0485e4b2e837ebb6cbd4f2451aba665a03e4b upstream. check_file_record() validates rec->total against the record size but never validates rec->used. The do_action() journal-replay handlers read rec->used from disk and use it to compute memmove lengths: DeleteAttribute: memmove(attr, ..., used - asize - roff) CreateAttribute: memmove(..., attr, used - roff) change_attr_size: memmove(..., used - PtrOffset(rec, next)) When rec->used is smaller than the offset of a validated attribute, or larger than the record size, these subtractions can underflow allowing us to copy huge amounts of memory in to a 4kb buffer, generally considered a bad idea overall. This requires a corrupted filesystem, which isn't a threat model the kernel really needs to worry about, but checking for such an obvious out-of-bounds value is good to keep things robust, especially on journal replay Fix this up by bounding rec->used correctly. This is much like commit b2bc7c44ed17 ("fs/ntfs3: Fix slab-out-of-bounds read in DeleteIndexEntryRoot") which checked different values in this same switch statement. Cc: Konstantin Komarov Fixes: b46acd6a6a62 ("fs/ntfs3: Add NTFS journal") Cc: stable Assisted-by: gregkh_clanker_t1000 Signed-off-by: Greg Kroah-Hartman Signed-off-by: Konstantin Komarov Signed-off-by: Greg Kroah-Hartman --- fs/ntfs3/fslog.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) --- a/fs/ntfs3/fslog.c +++ b/fs/ntfs3/fslog.c @@ -2791,13 +2791,14 @@ static inline bool check_file_record(con u16 fn = le16_to_cpu(rec->rhdr.fix_num); u16 ao = le16_to_cpu(rec->attr_off); u32 rs = sbi->record_size; + u32 used = le32_to_cpu(rec->used); /* Check the file record header for consistency. */ if (rec->rhdr.sign != NTFS_FILE_SIGNATURE || fo > (SECTOR_SIZE - ((rs >> SECTOR_SHIFT) + 1) * sizeof(short)) || (fn - 1) * SECTOR_SIZE != rs || ao < MFTRECORD_FIXUP_OFFSET_1 || ao > sbi->record_size - SIZEOF_RESIDENT || !is_rec_inuse(rec) || - le32_to_cpu(rec->total) != rs) { + le32_to_cpu(rec->total) != rs || used > rs || used < ao) { return false; } @@ -2809,6 +2810,15 @@ static inline bool check_file_record(con return false; } + /* + * The do_action() handlers compute memmove lengths as + * "rec->used - ", which underflows when + * rec->used is smaller than the attribute walk reached. At this + * point attr is the ATTR_END marker; rec->used must cover it. + */ + if (used < PtrOffset(rec, attr) + sizeof(attr->type)) + return false; + return true; }