From 50a6c8efa2bbeddf46ca34c7765024108202e04b Mon Sep 17 00:00:00 2001 From: Jeff King Date: Mon, 22 Feb 2016 17:44:35 -0500 Subject: [PATCH] use st_add and st_mult for allocation size computation If our size computation overflows size_t, we may allocate a much smaller buffer than we expected and overflow it. It's probably impossible to trigger an overflow in most of these sites in practice, but it is easy enough convert their additions and multiplications into overflow-checking variants. This may be fixing real bugs, and it makes auditing the code easier. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- archive.c | 4 ++-- builtin/apply.c | 2 +- builtin/clean.c | 2 +- builtin/fetch.c | 2 +- builtin/index-pack.c | 4 ++-- builtin/merge.c | 2 +- builtin/mv.c | 4 ++-- builtin/receive-pack.c | 2 +- combine-diff.c | 14 +++++++------- commit.c | 2 +- compat/mingw.c | 4 ++-- compat/qsort.c | 2 +- compat/setenv.c | 2 +- compat/win32/syslog.c | 4 ++-- diffcore-delta.c | 6 ++++-- diffcore-rename.c | 2 +- dir.c | 4 ++-- fast-import.c | 2 +- refs.c | 2 +- remote.c | 8 ++++---- revision.c | 2 +- sha1_file.c | 20 +++++++++++--------- sha1_name.c | 5 ++--- shallow.c | 2 +- submodule.c | 6 +++--- 25 files changed, 56 insertions(+), 53 deletions(-) diff --git a/archive.c b/archive.c index 0687afae434e55..5d735ae6039f0d 100644 --- a/archive.c +++ b/archive.c @@ -171,8 +171,8 @@ static void queue_directory(const unsigned char *sha1, unsigned mode, int stage, struct archiver_context *c) { struct directory *d; - size_t len = base->len + 1 + strlen(filename) + 1; - d = xmalloc(sizeof(*d) + len); + size_t len = st_add4(base->len, 1, strlen(filename), 1); + d = xmalloc(st_add(sizeof(*d), len)); d->up = c->bottom; d->baselen = base->len; d->mode = mode; diff --git a/builtin/apply.c b/builtin/apply.c index deb1364fa81452..0db6d14cc2eeaf 100644 --- a/builtin/apply.c +++ b/builtin/apply.c @@ -2632,7 +2632,7 @@ static void update_image(struct image *img, insert_count = postimage->len; /* Adjust the contents */ - result = xmalloc(img->len + insert_count - remove_count + 1); + result = xmalloc(st_add3(st_sub(img->len, remove_count), insert_count, 1)); memcpy(result, img->buf, applied_at); memcpy(result + applied_at, postimage->buf, postimage->len); memcpy(result + applied_at + postimage->len, diff --git a/builtin/clean.c b/builtin/clean.c index 1f02c8294cb682..fb1824ce951b62 100644 --- a/builtin/clean.c +++ b/builtin/clean.c @@ -615,7 +615,7 @@ static int *list_and_choose(struct menu_opts *opts, struct menu_stuff *stuff) nr += chosen[i]; } - result = xcalloc(nr + 1, sizeof(int)); + result = xcalloc(st_add(nr, 1), sizeof(int)); for (i = 0; i < stuff->nr && j < nr; i++) { if (chosen[i]) result[j++] = i; diff --git a/builtin/fetch.c b/builtin/fetch.c index 17f40e10f6960e..683f08ec91295e 100644 --- a/builtin/fetch.c +++ b/builtin/fetch.c @@ -1107,7 +1107,7 @@ static int fetch_one(struct remote *remote, int argc, const char **argv) if (argc > 0) { int j = 0; int i; - refs = xcalloc(argc + 1, sizeof(const char *)); + refs = xcalloc(st_add(argc, 1), sizeof(const char *)); for (i = 0; i < argc; i++) { if (!strcmp(argv[i], "tag")) { i++; diff --git a/builtin/index-pack.c b/builtin/index-pack.c index a60bcfac0646b6..193908a619307f 100644 --- a/builtin/index-pack.c +++ b/builtin/index-pack.c @@ -1744,9 +1744,9 @@ int cmd_index_pack(int argc, const char **argv, const char *prefix) curr_pack = open_pack_file(pack_name); parse_pack_header(); - objects = xcalloc(nr_objects + 1, sizeof(struct object_entry)); + objects = xcalloc(st_add(nr_objects, 1), sizeof(struct object_entry)); if (show_stat) - obj_stat = xcalloc(nr_objects + 1, sizeof(struct object_stat)); + obj_stat = xcalloc(st_add(nr_objects, 1), sizeof(struct object_stat)); ofs_deltas = xcalloc(nr_objects, sizeof(struct ofs_delta_entry)); parse_pack_objects(pack_sha1); resolve_deltas(); diff --git a/builtin/merge.c b/builtin/merge.c index b98a3489bf24c0..101ffeff4c9426 100644 --- a/builtin/merge.c +++ b/builtin/merge.c @@ -939,7 +939,7 @@ static int setup_with_upstream(const char ***argv) if (!branch->merge_nr) die(_("No default upstream defined for the current branch.")); - args = xcalloc(branch->merge_nr + 1, sizeof(char *)); + args = xcalloc(st_add(branch->merge_nr, 1), sizeof(char *)); for (i = 0; i < branch->merge_nr; i++) { if (!branch->merge[i]->dst) die(_("No remote-tracking branch for %s from %s"), diff --git a/builtin/mv.c b/builtin/mv.c index 9a9813a0eca328..aeae855e2b9539 100644 --- a/builtin/mv.c +++ b/builtin/mv.c @@ -48,9 +48,9 @@ static const char **internal_copy_pathspec(const char *prefix, static const char *add_slash(const char *path) { - int len = strlen(path); + size_t len = strlen(path); if (path[len - 1] != '/') { - char *with_slash = xmalloc(len + 2); + char *with_slash = xmalloc(st_add(len, 2)); memcpy(with_slash, path, len); with_slash[len++] = '/'; with_slash[len] = 0; diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c index 3dc3868c8694f3..c8e32b297c4be6 100644 --- a/builtin/receive-pack.c +++ b/builtin/receive-pack.c @@ -1372,7 +1372,7 @@ static struct command **queue_command(struct command **tail, refname = line + 82; reflen = linelen - 82; - cmd = xcalloc(1, sizeof(struct command) + reflen + 1); + cmd = xcalloc(1, st_add3(sizeof(struct command), reflen, 1)); hashcpy(cmd->old_sha1, old_sha1); hashcpy(cmd->new_sha1, new_sha1); memcpy(cmd->ref_name, refname, reflen); diff --git a/combine-diff.c b/combine-diff.c index be09a2b25cad12..0e1d4b0893ce02 100644 --- a/combine-diff.c +++ b/combine-diff.c @@ -189,11 +189,11 @@ static struct lline *coalesce_lines(struct lline *base, int *lenbase, * - Else if we have NEW, insert newend lline into base and * consume newend */ - lcs = xcalloc(origbaselen + 1, sizeof(int*)); - directions = xcalloc(origbaselen + 1, sizeof(enum coalesce_direction*)); + lcs = xcalloc(st_add(origbaselen, 1), sizeof(int*)); + directions = xcalloc(st_add(origbaselen, 1), sizeof(enum coalesce_direction*)); for (i = 0; i < origbaselen + 1; i++) { - lcs[i] = xcalloc(lennew + 1, sizeof(int)); - directions[i] = xcalloc(lennew + 1, sizeof(enum coalesce_direction)); + lcs[i] = xcalloc(st_add(lennew, 1), sizeof(int)); + directions[i] = xcalloc(st_add(lennew, 1), sizeof(enum coalesce_direction)); directions[i][0] = BASE; } for (j = 1; j < lennew + 1; j++) @@ -1111,7 +1111,7 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent, if (result_size && result[result_size-1] != '\n') cnt++; /* incomplete line */ - sline = xcalloc(cnt+2, sizeof(*sline)); + sline = xcalloc(st_add(cnt, 2), sizeof(*sline)); sline[0].bol = result; for (lno = 0, cp = result; cp < result + result_size; cp++) { if (*cp == '\n') { @@ -1130,7 +1130,7 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent, /* Even p_lno[cnt+1] is valid -- that is for the end line number * for deletion hunk at the end. */ - sline[0].p_lno = xcalloc((cnt+2) * num_parent, sizeof(unsigned long)); + sline[0].p_lno = xcalloc(st_mult(st_add(cnt, 2), num_parent), sizeof(unsigned long)); for (lno = 0; lno <= cnt; lno++) sline[lno+1].p_lno = sline[lno].p_lno + num_parent; @@ -1262,7 +1262,7 @@ static struct diff_filepair *combined_pair(struct combine_diff_path *p, struct diff_filespec *pool; pair = xmalloc(sizeof(*pair)); - pool = xcalloc(num_parent + 1, sizeof(struct diff_filespec)); + pool = xcalloc(st_add(num_parent, 1), sizeof(struct diff_filespec)); pair->one = pool + 1; pair->two = pool; diff --git a/commit.c b/commit.c index 31cd91f81ea54c..3f4f371e5eec41 100644 --- a/commit.c +++ b/commit.c @@ -147,7 +147,7 @@ struct commit_graft *read_graft_line(char *buf, int len) if ((len + 1) % entry_size) goto bad_graft_data; i = (len + 1) / entry_size - 1; - graft = xmalloc(sizeof(*graft) + GIT_SHA1_RAWSZ * i); + graft = xmalloc(st_add(sizeof(*graft), st_mult(GIT_SHA1_RAWSZ, i))); graft->nr_parent = i; if (get_oid_hex(buf, &graft->oid)) goto bad_graft_data; diff --git a/compat/mingw.c b/compat/mingw.c index d8a5345a305685..ae16d089ad234c 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -769,7 +769,7 @@ static const char *quote_arg(const char *arg) return arg; /* insert \ where necessary */ - d = q = xmalloc(len+n+3); + d = q = xmalloc(st_add3(len, n, 3)); *d++ = '"'; while (*arg) { if (*arg == '"') @@ -1028,7 +1028,7 @@ static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **deltaen free(quoted); } - wargs = xmalloc((2 * args.len + 1) * sizeof(wchar_t)); + wargs = xmalloc_array(st_add(st_mult(2, args.len), 1), sizeof(wchar_t)); xutftowcs(wargs, args.buf, 2 * args.len + 1); strbuf_release(&args); diff --git a/compat/qsort.c b/compat/qsort.c index 9574d537bd38d3..7d071afb70530e 100644 --- a/compat/qsort.c +++ b/compat/qsort.c @@ -47,7 +47,7 @@ static void msort_with_tmp(void *b, size_t n, size_t s, void git_qsort(void *b, size_t n, size_t s, int (*cmp)(const void *, const void *)) { - const size_t size = n * s; + const size_t size = st_mult(n, s); char buf[1024]; if (size < sizeof(buf)) { diff --git a/compat/setenv.c b/compat/setenv.c index fc1439a6439393..7849f258d20195 100644 --- a/compat/setenv.c +++ b/compat/setenv.c @@ -18,7 +18,7 @@ int gitsetenv(const char *name, const char *value, int replace) namelen = strlen(name); valuelen = strlen(value); - envstr = malloc((namelen + valuelen + 2)); + envstr = malloc(st_add3(namelen, valuelen, 2)); if (!envstr) { errno = ENOMEM; return -1; diff --git a/compat/win32/syslog.c b/compat/win32/syslog.c index d015e436d57472..b905aea31bf53d 100644 --- a/compat/win32/syslog.c +++ b/compat/win32/syslog.c @@ -32,7 +32,7 @@ void syslog(int priority, const char *fmt, ...) return; } - str = malloc(str_len + 1); + str = malloc(st_add(str_len, 1)); if (!str) { warning("malloc failed: '%s'", strerror(errno)); return; @@ -43,7 +43,7 @@ void syslog(int priority, const char *fmt, ...) va_end(ap); while ((pos = strstr(str, "%1")) != NULL) { - str = realloc(str, ++str_len + 1); + str = realloc(str, st_add(++str_len, 1)); if (!str) { warning("realloc failed: '%s'", strerror(errno)); return; diff --git a/diffcore-delta.c b/diffcore-delta.c index 7cf431d261f9a3..4159748a70ccc0 100644 --- a/diffcore-delta.c +++ b/diffcore-delta.c @@ -53,7 +53,8 @@ static struct spanhash_top *spanhash_rehash(struct spanhash_top *orig) int osz = 1 << orig->alloc_log2; int sz = osz << 1; - new = xmalloc(sizeof(*orig) + sizeof(struct spanhash) * sz); + new = xmalloc(st_add(sizeof(*orig), + st_mult(sizeof(struct spanhash), sz))); new->alloc_log2 = orig->alloc_log2 + 1; new->free = INITIAL_FREE(new->alloc_log2); memset(new->data, 0, sizeof(struct spanhash) * sz); @@ -130,7 +131,8 @@ static struct spanhash_top *hash_chars(struct diff_filespec *one) int is_text = !diff_filespec_is_binary(one); i = INITIAL_HASH_SIZE; - hash = xmalloc(sizeof(*hash) + sizeof(struct spanhash) * (1<alloc_log2 = i; hash->free = INITIAL_FREE(i); memset(hash->data, 0, sizeof(struct spanhash) * (1< rd->end) return -1; - *untracked_ = untracked = xmalloc(sizeof(*untracked) + len); + *untracked_ = untracked = xmalloc(st_add(sizeof(*untracked), len)); memcpy(untracked, &ud, sizeof(ud)); memcpy(untracked->name, data, len + 1); data = next; diff --git a/fast-import.c b/fast-import.c index 36dbaa5b165134..9622b89df73491 100644 --- a/fast-import.c +++ b/fast-import.c @@ -622,7 +622,7 @@ static void *pool_alloc(size_t len) return xmalloc(len); } total_allocd += sizeof(struct mem_pool) + mem_pool_alloc; - p = xmalloc(sizeof(struct mem_pool) + mem_pool_alloc); + p = xmalloc(st_add(sizeof(struct mem_pool), mem_pool_alloc)); p->next_pool = mem_pool; p->next_free = (char *) p->space; p->end = p->next_free + mem_pool_alloc; diff --git a/refs.c b/refs.c index 2d864452315fd3..b0e6ece6f43437 100644 --- a/refs.c +++ b/refs.c @@ -906,7 +906,7 @@ char *shorten_unambiguous_ref(const char *refname, int strict) /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */ total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1; - scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len); + scanf_fmts = xmalloc(st_add(st_mult(nr_rules, sizeof(char *)), total_len)); offset = 0; for (i = 0; i < nr_rules; i++) { diff --git a/remote.c b/remote.c index 7a8a8a1b4a9074..f182382c834ee9 100644 --- a/remote.c +++ b/remote.c @@ -928,7 +928,7 @@ static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen, const char *name) { size_t len = strlen(name); - struct ref *ref = xcalloc(1, sizeof(struct ref) + prefixlen + len + 1); + struct ref *ref = xcalloc(1, st_add4(sizeof(*ref), prefixlen, len, 1)); memcpy(ref->name, prefix, prefixlen); memcpy(ref->name + prefixlen, name, len); return ref; @@ -945,9 +945,9 @@ struct ref *copy_ref(const struct ref *ref) size_t len; if (!ref) return NULL; - len = strlen(ref->name); - cpy = xmalloc(sizeof(struct ref) + len + 1); - memcpy(cpy, ref, sizeof(struct ref) + len + 1); + len = st_add3(sizeof(struct ref), strlen(ref->name), 1); + cpy = xmalloc(len); + memcpy(cpy, ref, len); cpy->next = NULL; cpy->symref = xstrdup_or_null(ref->symref); cpy->remote_status = xstrdup_or_null(ref->remote_status); diff --git a/revision.c b/revision.c index 14daefb1745019..df56fcea0e12a1 100644 --- a/revision.c +++ b/revision.c @@ -540,7 +540,7 @@ struct treesame_state { static struct treesame_state *initialise_treesame(struct rev_info *revs, struct commit *commit) { unsigned n = commit_list_count(commit->parents); - struct treesame_state *st = xcalloc(1, sizeof(*st) + n); + struct treesame_state *st = xcalloc(1, st_add(sizeof(*st), n)); st->nparents = n; add_decoration(&revs->treesame, &commit->object, st); return st; diff --git a/sha1_file.c b/sha1_file.c index d14abfed9b5697..ab16c7b98cbd72 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -253,7 +253,7 @@ static int link_alt_odb_entry(const char *entry, const char *relative_base, { struct alternate_object_database *ent; struct alternate_object_database *alt; - int pfxlen, entlen; + size_t pfxlen, entlen; struct strbuf pathbuf = STRBUF_INIT; if (!is_absolute_path(entry) && relative_base) { @@ -273,8 +273,8 @@ static int link_alt_odb_entry(const char *entry, const char *relative_base, while (pfxlen && pathbuf.buf[pfxlen-1] == '/') pfxlen -= 1; - entlen = pfxlen + 43; /* '/' + 2 hex + '/' + 38 hex + NUL */ - ent = xmalloc(sizeof(*ent) + entlen); + entlen = st_add(pfxlen, 43); /* '/' + 2 hex + '/' + 38 hex + NUL */ + ent = xmalloc(st_add(sizeof(*ent), entlen)); memcpy(ent->base, pathbuf.buf, pfxlen); strbuf_release(&pathbuf); @@ -1134,7 +1134,7 @@ unsigned char *use_pack(struct packed_git *p, static struct packed_git *alloc_packed_git(int extra) { - struct packed_git *p = xmalloc(sizeof(*p) + extra); + struct packed_git *p = xmalloc(st_add(sizeof(*p), extra)); memset(p, 0, sizeof(*p)); p->pack_fd = -1; return p; @@ -1168,7 +1168,7 @@ struct packed_git *add_packed_git(const char *path, size_t path_len, int local) * ".pack" is long enough to hold any suffix we're adding (and * the use xsnprintf double-checks that) */ - alloc = path_len + strlen(".pack") + 1; + alloc = st_add3(path_len, strlen(".pack"), 1); p = alloc_packed_git(alloc); memcpy(p->pack_name, path, path_len); @@ -1196,7 +1196,7 @@ struct packed_git *add_packed_git(const char *path, size_t path_len, int local) struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path) { const char *path = sha1_pack_name(sha1); - int alloc = strlen(path) + 1; + size_t alloc = st_add(strlen(path), 1); struct packed_git *p = alloc_packed_git(alloc); memcpy(p->pack_name, path, alloc); /* includes NUL */ @@ -1413,10 +1413,12 @@ static void mark_bad_packed_object(struct packed_git *p, { unsigned i; for (i = 0; i < p->num_bad_objects; i++) - if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i)) + if (!hashcmp(sha1, p->bad_object_sha1 + GIT_SHA1_RAWSZ * i)) return; - p->bad_object_sha1 = xrealloc(p->bad_object_sha1, 20 * (p->num_bad_objects + 1)); - hashcpy(p->bad_object_sha1 + 20 * p->num_bad_objects, sha1); + p->bad_object_sha1 = xrealloc(p->bad_object_sha1, + st_mult(GIT_SHA1_RAWSZ, + st_add(p->num_bad_objects, 1))); + hashcpy(p->bad_object_sha1 + GIT_SHA1_RAWSZ * p->num_bad_objects, sha1); p->num_bad_objects++; } diff --git a/sha1_name.c b/sha1_name.c index 892db21813bc48..532db4fdc6dcf9 100644 --- a/sha1_name.c +++ b/sha1_name.c @@ -87,9 +87,8 @@ static void find_short_object_filename(int len, const char *hex_pfx, struct disa * object databases including our own. */ const char *objdir = get_object_directory(); - int objdir_len = strlen(objdir); - int entlen = objdir_len + 43; - fakeent = xmalloc(sizeof(*fakeent) + entlen); + size_t objdir_len = strlen(objdir); + fakeent = xmalloc(st_add3(sizeof(*fakeent), objdir_len, 43)); memcpy(fakeent->base, objdir, objdir_len); fakeent->name = fakeent->base + objdir_len + 1; fakeent->name[-1] = '/'; diff --git a/shallow.c b/shallow.c index 71163bf3d7c8d5..4d554caf8d751d 100644 --- a/shallow.c +++ b/shallow.c @@ -389,7 +389,7 @@ static void paint_down(struct paint_info *info, const unsigned char *sha1, unsigned int i, nr; struct commit_list *head = NULL; int bitmap_nr = (info->nr_bits + 31) / 32; - int bitmap_size = bitmap_nr * sizeof(uint32_t); + size_t bitmap_size = st_mult(bitmap_nr, sizeof(uint32_t)); uint32_t *tmp = xmalloc(bitmap_size); /* to be freed before return */ uint32_t *bitmap = paint_alloc(info); struct commit *c = lookup_commit_reference_gently(sha1, 1); diff --git a/submodule.c b/submodule.c index 14e76247bf107d..bd97b15a9284c4 100644 --- a/submodule.c +++ b/submodule.c @@ -122,7 +122,7 @@ static int add_submodule_odb(const char *path) struct strbuf objects_directory = STRBUF_INIT; struct alternate_object_database *alt_odb; int ret = 0; - int alloc; + size_t alloc; strbuf_git_path_submodule(&objects_directory, path, "objects/"); if (!is_directory(objects_directory.buf)) { @@ -137,8 +137,8 @@ static int add_submodule_odb(const char *path) objects_directory.len)) goto done; - alloc = objects_directory.len + 42; /* for "12/345..." sha1 */ - alt_odb = xmalloc(sizeof(*alt_odb) + alloc); + alloc = st_add(objects_directory.len, 42); /* for "12/345..." sha1 */ + alt_odb = xmalloc(st_add(sizeof(*alt_odb), alloc)); alt_odb->next = alt_odb_list; xsnprintf(alt_odb->base, alloc, "%s", objects_directory.buf); alt_odb->name = alt_odb->base + objects_directory.len;