From c879daa23729547fb28aa7e8783c5e4e619a9e7c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?= Date: Sat, 5 Feb 2011 17:52:21 +0700 Subject: Make hash-object more robust against malformed objects MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commits, trees and tags have structure. Don't let users feed git with malformed ones. Sooner or later git will die() when encountering them. Note that this patch does not check semantics. A tree that points to non-existent objects is perfectly OK (and should be so, users may choose to add commit first, then its associated tree for example). Signed-off-by: Nguyễn Thái Ngọc Duy Signed-off-by: Junio C Hamano --- sha1_file.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 47 insertions(+), 7 deletions(-) (limited to 'sha1_file.c') diff --git a/sha1_file.c b/sha1_file.c index d86a8db69..58ca85835 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -13,6 +13,7 @@ #include "commit.h" #include "tag.h" #include "tree.h" +#include "tree-walk.h" #include "refs.h" #include "pack-revindex.h" #include "sha1-lookup.h" @@ -2471,8 +2472,37 @@ int has_sha1_file(const unsigned char *sha1) return has_loose_object(sha1); } +static void check_tree(const void *buf, size_t size) +{ + struct tree_desc desc; + struct name_entry entry; + + init_tree_desc(&desc, buf, size); + while (tree_entry(&desc, &entry)) + /* do nothing + * tree_entry() will die() on malformed entries */ + ; +} + +static void check_commit(const void *buf, size_t size) +{ + struct commit c; + memset(&c, 0, sizeof(c)); + if (parse_commit_buffer(&c, buf, size)) + die("corrupt commit"); +} + +static void check_tag(const void *buf, size_t size) +{ + struct tag t; + memset(&t, 0, sizeof(t)); + if (parse_tag_buffer(&t, buf, size)) + die("corrupt tag"); +} + static int index_mem(unsigned char *sha1, void *buf, size_t size, - int write_object, enum object_type type, const char *path) + int write_object, enum object_type type, + const char *path, int format_check) { int ret, re_allocated = 0; @@ -2490,6 +2520,14 @@ static int index_mem(unsigned char *sha1, void *buf, size_t size, re_allocated = 1; } } + if (format_check) { + if (type == OBJ_TREE) + check_tree(buf, size); + if (type == OBJ_COMMIT) + check_commit(buf, size); + if (type == OBJ_TAG) + check_tag(buf, size); + } if (write_object) ret = write_sha1_file(buf, size, typename(type), sha1); @@ -2503,7 +2541,7 @@ static int index_mem(unsigned char *sha1, void *buf, size_t size, #define SMALL_FILE_SIZE (32*1024) int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, - enum object_type type, const char *path) + enum object_type type, const char *path, int format_check) { int ret; size_t size = xsize_t(st->st_size); @@ -2512,23 +2550,25 @@ int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, struct strbuf sbuf = STRBUF_INIT; if (strbuf_read(&sbuf, fd, 4096) >= 0) ret = index_mem(sha1, sbuf.buf, sbuf.len, write_object, - type, path); + type, path, format_check); else ret = -1; strbuf_release(&sbuf); } else if (!size) { - ret = index_mem(sha1, NULL, size, write_object, type, path); + ret = index_mem(sha1, NULL, size, write_object, type, path, + format_check); } else if (size <= SMALL_FILE_SIZE) { char *buf = xmalloc(size); if (size == read_in_full(fd, buf, size)) ret = index_mem(sha1, buf, size, write_object, type, - path); + path, format_check); else ret = error("short read %s", strerror(errno)); free(buf); } else { void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0); - ret = index_mem(sha1, buf, size, write_object, type, path); + ret = index_mem(sha1, buf, size, write_object, type, path, + format_check); munmap(buf, size); } close(fd); @@ -2546,7 +2586,7 @@ int index_path(unsigned char *sha1, const char *path, struct stat *st, int write if (fd < 0) return error("open(\"%s\"): %s", path, strerror(errno)); - if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path) < 0) + if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path, 0) < 0) return error("%s: failed to insert into database", path); break; -- cgit v1.2.1