From patchwork Fri Nov 13 05:07:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff King X-Patchwork-Id: 11902513 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9A7FBC388F9 for ; Fri, 13 Nov 2020 05:07:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4CC5520B80 for ; Fri, 13 Nov 2020 05:07:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726198AbgKMFHP (ORCPT ); Fri, 13 Nov 2020 00:07:15 -0500 Received: from cloud.peff.net ([104.130.231.41]:56918 "EHLO cloud.peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726054AbgKMFHP (ORCPT ); Fri, 13 Nov 2020 00:07:15 -0500 Received: (qmail 23770 invoked by uid 109); 13 Nov 2020 05:07:15 -0000 Received: from Unknown (HELO peff.net) (10.0.1.2) by cloud.peff.net (qpsmtpd/0.94) with ESMTP; Fri, 13 Nov 2020 05:07:15 +0000 Authentication-Results: cloud.peff.net; auth=none Received: (qmail 6208 invoked by uid 111); 13 Nov 2020 05:07:14 -0000 Received: from coredump.intra.peff.net (HELO sigill.intra.peff.net) (10.0.0.2) by peff.net (qpsmtpd/0.94) with (TLS_AES_256_GCM_SHA384 encrypted) ESMTPS; Fri, 13 Nov 2020 00:07:14 -0500 Authentication-Results: peff.net; auth=none Date: Fri, 13 Nov 2020 00:07:14 -0500 From: Jeff King To: git@vger.kernel.org Subject: [PATCH 3/5] fsck: correctly compute checksums on idx files larger than 4GB Message-ID: <20201113050714.GC744691@coredump.intra.peff.net> References: <20201113050631.GA744608@coredump.intra.peff.net> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20201113050631.GA744608@coredump.intra.peff.net> Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org When checking the trailing checksum hash of a .idx file, we pass the whole buffer (minus the trailing hash) into a single call to the_hash_algo->update_fn(). But we cast it to an "unsigned int". This comes from c4001d92be (Use off_t when we really mean a file offset., 2007-03-06). That commit started storing the index_size variable as an off_t, but our mozilla-sha1 implementation from the time was limited to a smaller size. Presumably the cast was a way of annotating that we expected .idx files to be small, and so we didn't need to loop (as we do for arbitrarily-large .pack files). Though as an aside it was still wrong, because the mozilla function actually took a signed int. These days our hash-update functions are defined to take a size_t, so we can pass the whole buffer in directly. The cast is actually causing a buggy truncation! While we're here, though, let's drop the confusing off_t variable in the first place. We're getting the size not from the filesystem anyway, but from p->index_size, which is a size_t. In fact, we can make the code a bit more readable by dropping our local variable duplicating p->index_size, and instead have one that stores the size of the actual index data, minus the trailing hash. Signed-off-by: Jeff King --- pack-check.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/pack-check.c b/pack-check.c index db3adf8781..4b089fe8ec 100644 --- a/pack-check.c +++ b/pack-check.c @@ -164,22 +164,22 @@ static int verify_packfile(struct repository *r, int verify_pack_index(struct packed_git *p) { - off_t index_size; + size_t len; const unsigned char *index_base; git_hash_ctx ctx; unsigned char hash[GIT_MAX_RAWSZ]; int err = 0; if (open_pack_index(p)) return error("packfile %s index not opened", p->pack_name); - index_size = p->index_size; index_base = p->index_data; + len = p->index_size - the_hash_algo->rawsz; /* Verify SHA1 sum of the index file */ the_hash_algo->init_fn(&ctx); - the_hash_algo->update_fn(&ctx, index_base, (unsigned int)(index_size - the_hash_algo->rawsz)); + the_hash_algo->update_fn(&ctx, index_base, len); the_hash_algo->final_fn(hash, &ctx); - if (!hasheq(hash, index_base + index_size - the_hash_algo->rawsz)) + if (!hasheq(hash, index_base + len)) err = error("Packfile index for %s hash mismatch", p->pack_name); return err;