From patchwork Fri Dec 23 20:36:28 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 13081154 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C69F0C3DA79 for ; Fri, 23 Dec 2022 20:37:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233110AbiLWUg7 (ORCPT ); Fri, 23 Dec 2022 15:36:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56416 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232834AbiLWUg6 (ORCPT ); Fri, 23 Dec 2022 15:36:58 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7236C1D309; Fri, 23 Dec 2022 12:36:57 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0630261EED; Fri, 23 Dec 2022 20:36:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2C4AAC433F0; Fri, 23 Dec 2022 20:36:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1671827816; bh=iUdBvdNiQeVKQXe2/6eUg98m/CYbzWe1kqf/gTptRGs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=o8C+LgP264e1gacZYiTziQL/GH12JCvASKiy5SXoD1HtZfRYZgkHJnfdt2sNMXL0v X34BZqbXGrrKNvyzK3y83BjWzbYzV5+Q1Is+CpOJXNGdxZDkXLyjDTQUga5Q2CZpCw OqVIOMlddULiPdjDnZ3AymdRzg1VekEkK3hxKn9z04fj6l6qHYAgUz5kgQN0f41Od9 gAi0ffWHW59SXVPnfoc5xbsnhxtkkvYOI/9lYfpiJE0UuQWSj5+gwE6Mx9N32bmvLx gZsX1DoA4hCdVrVaOBmsJQJMOwKM95SYpLYribt5jmS/hpnI7h7Xb+DI4LHfKiL+mL ZLwS/xH9MtKVQ== From: Eric Biggers To: linux-fscrypt@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-btrfs@vger.kernel.org, linux-xfs@vger.kernel.org, Andrey Albershteyn Subject: [PATCH v2 01/11] fsverity: use unsigned long for level_start Date: Fri, 23 Dec 2022 12:36:28 -0800 Message-Id: <20221223203638.41293-2-ebiggers@kernel.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20221223203638.41293-1-ebiggers@kernel.org> References: <20221223203638.41293-1-ebiggers@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org From: Eric Biggers fs/verity/ isn't consistent with whether Merkle tree block indices are 'unsigned long' or 'u64'. There's no real point to using u64 for them, though, since (a) a Merkle tree with over ULONG_MAX blocks would only be needed for a file larger than MAX_LFS_FILESIZE, and (b) for reads, the status of all Merkle tree blocks has to be tracked in memory. Therefore, let's make things a bit more efficient on 32-bit systems by using 'unsigned long[]' for merkle_tree_params::level_start, instead of 'u64[]'. Also, to be extra safe, explicitly check that there aren't more than ULONG_MAX Merkle tree blocks. Signed-off-by: Eric Biggers --- fs/verity/fsverity_private.h | 2 +- fs/verity/open.c | 20 +++++++++++++++----- 2 files changed, 16 insertions(+), 6 deletions(-) diff --git a/fs/verity/fsverity_private.h b/fs/verity/fsverity_private.h index a16038a0ee67d..e8b40c8000be7 100644 --- a/fs/verity/fsverity_private.h +++ b/fs/verity/fsverity_private.h @@ -52,7 +52,7 @@ struct merkle_tree_params { * Starting block index for each tree level, ordered from leaf level (0) * to root level ('num_levels - 1') */ - u64 level_start[FS_VERITY_MAX_LEVELS]; + unsigned long level_start[FS_VERITY_MAX_LEVELS]; }; /* diff --git a/fs/verity/open.c b/fs/verity/open.c index e0ef1a6283943..83ccc3c137363 100644 --- a/fs/verity/open.c +++ b/fs/verity/open.c @@ -34,6 +34,7 @@ int fsverity_init_merkle_tree_params(struct merkle_tree_params *params, struct fsverity_hash_alg *hash_alg; int err; u64 blocks; + u64 blocks_in_level[FS_VERITY_MAX_LEVELS]; u64 offset; int level; @@ -94,17 +95,26 @@ int fsverity_init_merkle_tree_params(struct merkle_tree_params *params, } blocks = (blocks + params->hashes_per_block - 1) >> params->log_arity; - /* temporarily using level_start[] to store blocks in level */ - params->level_start[params->num_levels++] = blocks; + blocks_in_level[params->num_levels++] = blocks; } - params->level0_blocks = params->level_start[0]; + params->level0_blocks = blocks_in_level[0]; /* Compute the starting block of each level */ offset = 0; for (level = (int)params->num_levels - 1; level >= 0; level--) { - blocks = params->level_start[level]; params->level_start[level] = offset; - offset += blocks; + offset += blocks_in_level[level]; + } + + /* + * Since the data, and thus also the Merkle tree, cannot have more than + * ULONG_MAX pages, hash block indices can always fit in an + * 'unsigned long'. To be safe, explicitly check for it too. + */ + if (offset > ULONG_MAX) { + fsverity_err(inode, "Too many blocks in Merkle tree"); + err = -EFBIG; + goto out_err; } params->tree_size = offset << log_blocksize;