attr: fix out-of-bounds write when parsing huge number of attributes
[git/debian.git] / tree.c
blobe76517f6b180e4703a032706f6d388d491df22a5
1 #include "cache.h"
2 #include "cache-tree.h"
3 #include "tree.h"
4 #include "object-store.h"
5 #include "blob.h"
6 #include "commit.h"
7 #include "tag.h"
8 #include "alloc.h"
9 #include "tree-walk.h"
10 #include "repository.h"
12 const char *tree_type = "tree";
14 static int read_one_entry_opt(struct index_state *istate,
15 const struct object_id *oid,
16 const char *base, int baselen,
17 const char *pathname,
18 unsigned mode, int stage, int opt)
20 int len;
21 struct cache_entry *ce;
23 if (S_ISDIR(mode))
24 return READ_TREE_RECURSIVE;
26 len = strlen(pathname);
27 ce = make_empty_cache_entry(istate, baselen + len);
29 ce->ce_mode = create_ce_mode(mode);
30 ce->ce_flags = create_ce_flags(stage);
31 ce->ce_namelen = baselen + len;
32 memcpy(ce->name, base, baselen);
33 memcpy(ce->name + baselen, pathname, len+1);
34 oidcpy(&ce->oid, oid);
35 return add_index_entry(istate, ce, opt);
38 static int read_one_entry(const struct object_id *oid, struct strbuf *base,
39 const char *pathname, unsigned mode, int stage,
40 void *context)
42 struct index_state *istate = context;
43 return read_one_entry_opt(istate, oid, base->buf, base->len, pathname,
44 mode, stage,
45 ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
49 * This is used when the caller knows there is no existing entries at
50 * the stage that will conflict with the entry being added.
52 static int read_one_entry_quick(const struct object_id *oid, struct strbuf *base,
53 const char *pathname, unsigned mode, int stage,
54 void *context)
56 struct index_state *istate = context;
57 return read_one_entry_opt(istate, oid, base->buf, base->len, pathname,
58 mode, stage,
59 ADD_CACHE_JUST_APPEND);
62 static int read_tree_1(struct repository *r,
63 struct tree *tree, struct strbuf *base,
64 int stage, const struct pathspec *pathspec,
65 read_tree_fn_t fn, void *context)
67 struct tree_desc desc;
68 struct name_entry entry;
69 struct object_id oid;
70 int len, oldlen = base->len;
71 enum interesting retval = entry_not_interesting;
73 if (parse_tree(tree))
74 return -1;
76 init_tree_desc(&desc, tree->buffer, tree->size);
78 while (tree_entry(&desc, &entry)) {
79 if (retval != all_entries_interesting) {
80 retval = tree_entry_interesting(r->index, &entry,
81 base, 0, pathspec);
82 if (retval == all_entries_not_interesting)
83 break;
84 if (retval == entry_not_interesting)
85 continue;
88 switch (fn(&entry.oid, base,
89 entry.path, entry.mode, stage, context)) {
90 case 0:
91 continue;
92 case READ_TREE_RECURSIVE:
93 break;
94 default:
95 return -1;
98 if (S_ISDIR(entry.mode))
99 oidcpy(&oid, &entry.oid);
100 else if (S_ISGITLINK(entry.mode)) {
101 struct commit *commit;
103 commit = lookup_commit(r, &entry.oid);
104 if (!commit)
105 die("Commit %s in submodule path %s%s not found",
106 oid_to_hex(&entry.oid),
107 base->buf, entry.path);
109 if (parse_commit(commit))
110 die("Invalid commit %s in submodule path %s%s",
111 oid_to_hex(&entry.oid),
112 base->buf, entry.path);
114 oidcpy(&oid, get_commit_tree_oid(commit));
116 else
117 continue;
119 len = tree_entry_len(&entry);
120 strbuf_add(base, entry.path, len);
121 strbuf_addch(base, '/');
122 retval = read_tree_1(r, lookup_tree(r, &oid),
123 base, stage, pathspec,
124 fn, context);
125 strbuf_setlen(base, oldlen);
126 if (retval)
127 return -1;
129 return 0;
132 int read_tree_recursive(struct repository *r,
133 struct tree *tree,
134 const char *base, int baselen,
135 int stage, const struct pathspec *pathspec,
136 read_tree_fn_t fn, void *context)
138 struct strbuf sb = STRBUF_INIT;
139 int ret;
141 strbuf_add(&sb, base, baselen);
142 ret = read_tree_1(r, tree, &sb, stage, pathspec, fn, context);
143 strbuf_release(&sb);
144 return ret;
147 static int cmp_cache_name_compare(const void *a_, const void *b_)
149 const struct cache_entry *ce1, *ce2;
151 ce1 = *((const struct cache_entry **)a_);
152 ce2 = *((const struct cache_entry **)b_);
153 return cache_name_stage_compare(ce1->name, ce1->ce_namelen, ce_stage(ce1),
154 ce2->name, ce2->ce_namelen, ce_stage(ce2));
157 int read_tree(struct repository *r, struct tree *tree, int stage,
158 struct pathspec *match, struct index_state *istate)
160 read_tree_fn_t fn = NULL;
161 int i, err;
164 * Currently the only existing callers of this function all
165 * call it with stage=1 and after making sure there is nothing
166 * at that stage; we could always use read_one_entry_quick().
168 * But when we decide to straighten out git-read-tree not to
169 * use unpack_trees() in some cases, this will probably start
170 * to matter.
174 * See if we have cache entry at the stage. If so,
175 * do it the original slow way, otherwise, append and then
176 * sort at the end.
178 for (i = 0; !fn && i < istate->cache_nr; i++) {
179 const struct cache_entry *ce = istate->cache[i];
180 if (ce_stage(ce) == stage)
181 fn = read_one_entry;
184 if (!fn)
185 fn = read_one_entry_quick;
186 err = read_tree_recursive(r, tree, "", 0, stage, match, fn, istate);
187 if (fn == read_one_entry || err)
188 return err;
191 * Sort the cache entry -- we need to nuke the cache tree, though.
193 cache_tree_free(&istate->cache_tree);
194 QSORT(istate->cache, istate->cache_nr, cmp_cache_name_compare);
195 return 0;
198 struct tree *lookup_tree(struct repository *r, const struct object_id *oid)
200 struct object *obj = lookup_object(r, oid);
201 if (!obj)
202 return create_object(r, oid, alloc_tree_node(r));
203 return object_as_type(obj, OBJ_TREE, 0);
206 int parse_tree_buffer(struct tree *item, void *buffer, unsigned long size)
208 if (item->object.parsed)
209 return 0;
210 item->object.parsed = 1;
211 item->buffer = buffer;
212 item->size = size;
214 return 0;
217 int parse_tree_gently(struct tree *item, int quiet_on_missing)
219 enum object_type type;
220 void *buffer;
221 unsigned long size;
223 if (item->object.parsed)
224 return 0;
225 buffer = read_object_file(&item->object.oid, &type, &size);
226 if (!buffer)
227 return quiet_on_missing ? -1 :
228 error("Could not read %s",
229 oid_to_hex(&item->object.oid));
230 if (type != OBJ_TREE) {
231 free(buffer);
232 return error("Object %s not a tree",
233 oid_to_hex(&item->object.oid));
235 return parse_tree_buffer(item, buffer, size);
238 void free_tree_buffer(struct tree *tree)
240 FREE_AND_NULL(tree->buffer);
241 tree->size = 0;
242 tree->object.parsed = 0;
245 struct tree *parse_tree_indirect(const struct object_id *oid)
247 struct repository *r = the_repository;
248 struct object *obj = parse_object(r, oid);
249 return (struct tree *)repo_peel_to_type(r, NULL, 0, obj, OBJ_TREE);