From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-11.9 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI,T_DKIMWL_WL_MED, USER_IN_DEF_DKIM_WL shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id E13C720A1E for ; Fri, 7 Dec 2018 22:27:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726113AbeLGW1b (ORCPT ); Fri, 7 Dec 2018 17:27:31 -0500 Received: from mail-pg1-f202.google.com ([209.85.215.202]:48714 "EHLO mail-pg1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726041AbeLGW1a (ORCPT ); Fri, 7 Dec 2018 17:27:30 -0500 Received: by mail-pg1-f202.google.com with SMTP id r16so3526230pgr.15 for ; Fri, 07 Dec 2018 14:27:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=fUuaWZ9uILJ9U3kozA7uwqoXi2bGUMszdd9WsCZFdQk=; b=rVNQoLMk0cL3nUGoc+PfXxS7l6TwvjDDXJusGK87ccVOrwI6GTH0LPgBncJ3ctBcHy RQFPsLTvMX2Of0oI4D3oOdMf9Zw76ktmAu/evgsFRunfNwbjEfiZsilrWix86yR1Ld/l W1cMplK1hYtD6k2Y2XlOoNsHrVOziS1MLyRztY0g6cz9nHiZ5MB7psm3My21GQM9zYFJ AcI2mAbTsexIbA1SNg7t44oF5RNH0WjAgNrym82f2ipyNUK5jj/gN5Aa9Pq316vKIgsw MZVDZm6I5eYqbD9o/ZaKU6vB3Dq/WffK0whTI2sFdXo5CUWMplInjfHt0dKVhMPMpu84 P6Ig== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=fUuaWZ9uILJ9U3kozA7uwqoXi2bGUMszdd9WsCZFdQk=; b=EX9iS9h06bBGspOmxsmpQ/cbSzg3YDUFz8tH8I+Sp4/tLmIlWgluZvAr5tGwYszQnJ uAxY6WcOJJhUYYQMiXR3oECSiRE9429FKi9WwTHevVw7MBt3b1KF9ZXAgqdTFGU+LCNr 2dAyG4dE0787VS7c0qfvYxuZYyrkyT4SplNeMhhUW1Pw2cK/viknS3NqK+b7w1jeOyhJ xUP2udNbW7em3Cn1ZKhegleegofehwClkKEOoRzVP3H9oQrwedlscSSEHQwniWVYeuGM x5M9xDBNWQ7TLxbnkfhlWFEHQq1SzBYZuQs34HjcgZd5kPU8iG/tLkwN3nmQtyB6DsVo 63hA== X-Gm-Message-State: AA+aEWbVnyXOEoHvLdBeceLOndPhtTZ1H6Qiky+TruLTF45oVqEEFXZj 4q9HJml5v972Ub3/qekpaDlc4qBQwkIvT6w9fZKrwkAVP0WuT0Bms+LbrzpSLGiXDX0z2GNsIGF 2GWxq/rT8+DXtnTNDKlRyaCSrhM+/BcG94cGfEv4j4aa/R6Pq3Jc6IUXFGa4QP1c= X-Google-Smtp-Source: AFSGD/UqEWHL/gME1/fMyGQb/7LtkHfI/4CackTh5MlY0LvjRZKNVx4YyFmQaJAl+18+is6yVQ1UPhAbEIHuew== X-Received: by 2002:a63:da56:: with SMTP id l22mr2017069pgj.6.1544221649731; Fri, 07 Dec 2018 14:27:29 -0800 (PST) Date: Fri, 7 Dec 2018 14:27:22 -0800 In-Reply-To: Message-Id: <0b57ecbe1b6c72d95311ba1bb30ea1ed9fd7e3e5.1544221121.git.steadmon@google.com> Mime-Version: 1.0 References: X-Mailer: git-send-email 2.20.0.rc2.403.gdbc3b29805-goog Subject: [PATCH v3 1/3] commit-graph, fuzz: Add fuzzer for commit-graph From: Josh Steadmon To: git@vger.kernel.org Cc: gitster@pobox.com, stolee@gmail.com, avarab@gmail.com, peff@peff.net Content-Type: text/plain; charset="UTF-8" Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Breaks load_commit_graph_one() into a new function, parse_commit_graph(). The latter function operates on arbitrary buffers, which makes it suitable as a fuzzing target. Since parse_commit_graph() is only called by load_commit_graph_one() (and the fuzzer described below), we omit error messages that would be duplicated by the caller. Adds fuzz-commit-graph.c, which provides a fuzzing entry point compatible with libFuzzer (and possibly other fuzzing engines). Signed-off-by: Josh Steadmon --- .gitignore | 1 + Makefile | 1 + commit-graph.c | 53 ++++++++++++++++++++++++++++++--------------- commit-graph.h | 3 +++ fuzz-commit-graph.c | 16 ++++++++++++++ 5 files changed, 57 insertions(+), 17 deletions(-) create mode 100644 fuzz-commit-graph.c diff --git a/.gitignore b/.gitignore index 0d77ea5894..8bcf153ed9 100644 --- a/.gitignore +++ b/.gitignore @@ -1,3 +1,4 @@ +/fuzz-commit-graph /fuzz_corpora /fuzz-pack-headers /fuzz-pack-idx diff --git a/Makefile b/Makefile index 1a44c811aa..6b72f37c29 100644 --- a/Makefile +++ b/Makefile @@ -684,6 +684,7 @@ SCRIPTS = $(SCRIPT_SH_INS) \ ETAGS_TARGET = TAGS +FUZZ_OBJS += fuzz-commit-graph.o FUZZ_OBJS += fuzz-pack-headers.o FUZZ_OBJS += fuzz-pack-idx.o diff --git a/commit-graph.c b/commit-graph.c index 40c855f185..07dd410f3c 100644 --- a/commit-graph.c +++ b/commit-graph.c @@ -84,16 +84,10 @@ static int commit_graph_compatible(struct repository *r) struct commit_graph *load_commit_graph_one(const char *graph_file) { void *graph_map; - const unsigned char *data, *chunk_lookup; size_t graph_size; struct stat st; - uint32_t i; - struct commit_graph *graph; + struct commit_graph *ret; int fd = git_open(graph_file); - uint64_t last_chunk_offset; - uint32_t last_chunk_id; - uint32_t graph_signature; - unsigned char graph_version, hash_version; if (fd < 0) return NULL; @@ -108,27 +102,55 @@ struct commit_graph *load_commit_graph_one(const char *graph_file) die(_("graph file %s is too small"), graph_file); } graph_map = xmmap(NULL, graph_size, PROT_READ, MAP_PRIVATE, fd, 0); + ret = parse_commit_graph(graph_map, fd, graph_size); + + if (!ret) { + munmap(graph_map, graph_size); + close(fd); + exit(1); + } + + return ret; +} + +struct commit_graph *parse_commit_graph(void *graph_map, int fd, + size_t graph_size) +{ + const unsigned char *data, *chunk_lookup; + uint32_t i; + struct commit_graph *graph; + uint64_t last_chunk_offset; + uint32_t last_chunk_id; + uint32_t graph_signature; + unsigned char graph_version, hash_version; + + if (!graph_map) + return NULL; + + if (graph_size < GRAPH_MIN_SIZE) + return NULL; + data = (const unsigned char *)graph_map; graph_signature = get_be32(data); if (graph_signature != GRAPH_SIGNATURE) { error(_("graph signature %X does not match signature %X"), graph_signature, GRAPH_SIGNATURE); - goto cleanup_fail; + return NULL; } graph_version = *(unsigned char*)(data + 4); if (graph_version != GRAPH_VERSION) { error(_("graph version %X does not match version %X"), graph_version, GRAPH_VERSION); - goto cleanup_fail; + return NULL; } hash_version = *(unsigned char*)(data + 5); if (hash_version != GRAPH_OID_VERSION) { error(_("hash version %X does not match version %X"), hash_version, GRAPH_OID_VERSION); - goto cleanup_fail; + return NULL; } graph = alloc_commit_graph(); @@ -152,7 +174,8 @@ struct commit_graph *load_commit_graph_one(const char *graph_file) if (chunk_offset > graph_size - GIT_MAX_RAWSZ) { error(_("improper chunk offset %08x%08x"), (uint32_t)(chunk_offset >> 32), (uint32_t)chunk_offset); - goto cleanup_fail; + free(graph); + return NULL; } switch (chunk_id) { @@ -187,7 +210,8 @@ struct commit_graph *load_commit_graph_one(const char *graph_file) if (chunk_repeated) { error(_("chunk id %08x appears multiple times"), chunk_id); - goto cleanup_fail; + free(graph); + return NULL; } if (last_chunk_id == GRAPH_CHUNKID_OIDLOOKUP) @@ -201,11 +225,6 @@ struct commit_graph *load_commit_graph_one(const char *graph_file) } return graph; - -cleanup_fail: - munmap(graph_map, graph_size); - close(fd); - exit(1); } static void prepare_commit_graph_one(struct repository *r, const char *obj_dir) diff --git a/commit-graph.h b/commit-graph.h index 9db40b4d3a..813e7c19f1 100644 --- a/commit-graph.h +++ b/commit-graph.h @@ -54,6 +54,9 @@ struct commit_graph { struct commit_graph *load_commit_graph_one(const char *graph_file); +struct commit_graph *parse_commit_graph(void *graph_map, int fd, + size_t graph_size); + /* * Return 1 if and only if the repository has a commit-graph * file and generation numbers are computed in that file. diff --git a/fuzz-commit-graph.c b/fuzz-commit-graph.c new file mode 100644 index 0000000000..cf790c9d04 --- /dev/null +++ b/fuzz-commit-graph.c @@ -0,0 +1,16 @@ +#include "commit-graph.h" + +struct commit_graph *parse_commit_graph(void *graph_map, int fd, + size_t graph_size); + +int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size); + +int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) +{ + struct commit_graph *g; + + g = parse_commit_graph((void *)data, -1, size); + free(g); + + return 0; +} -- 2.20.0.rc2.12.g4c11c11dec