66 free_stree(&start_states);
67 }
68
69 static void match_save_states(struct expression *expr)
70 {
71 push_stree(&saved_stack, start_states);
72 start_states = NULL;
73 }
74
75 static void match_restore_states(struct expression *expr)
76 {
77 free_stree(&start_states);
78 start_states = pop_stree(&saved_stack);
79 }
80
81 static struct smatch_state *empty_state(struct sm_state *sm)
82 {
83 return alloc_estate_empty();
84 }
85
86 static void pre_merge_hook(struct sm_state *sm)
87 {
88 struct smatch_state *user;
89 struct smatch_state *extra;
90 struct smatch_state *state;
91 struct range_list *rl;
92 sval_t dummy;
93 sval_t sval_100;
94
95 sval_100.value = 100;
96 sval_100.type = &int_ctype;
97
98 user = __get_state(my_id, sm->name, sm->sym);
99 if (!user || !estate_rl(user))
100 return;
101 extra = __get_state(SMATCH_EXTRA, sm->name, sm->sym);
102 if (!extra)
103 return;
104 rl = rl_intersection(estate_rl(user), estate_rl(extra));
105 if (rl_to_sval(rl, &dummy))
106 rl = NULL;
107 state = alloc_estate_rl(clone_rl(rl));
108 if (estate_capped(user) || is_capped_var_sym(sm->name, sm->sym))
109 estate_set_capped(state);
110 set_state(my_id, sm->name, sm->sym, state);
111 }
112
113 static void extra_nomod_hook(const char *name, struct symbol *sym, struct expression *expr, struct smatch_state *state)
114 {
115 struct smatch_state *user, *new;
116 struct range_list *rl;
117
118 user = __get_state(my_id, name, sym);
119 if (!user)
120 return;
121 rl = rl_intersection(estate_rl(user), estate_rl(state));
122 if (rl_equiv(rl, estate_rl(user)))
123 return;
124 new = alloc_estate_rl(rl);
125 if (estate_capped(user))
126 estate_set_capped(new);
127 set_state(my_id, name, sym, new);
128 }
129
130 static bool binop_capped(struct expression *expr)
131 {
132 struct range_list *left_rl;
133 int comparison;
134
135 if (expr->op == '-' && get_user_rl(expr->left, &left_rl)) {
136 if (user_rl_capped(expr->left))
137 return true;
138 comparison = get_comparison(expr->left, expr->right);
139 if (comparison && show_special(comparison)[0] == '>')
140 return true;
141 return false;
142 }
143
144 if (expr->op == '&' || expr->op == '%') {
145 if (is_capped(expr->left) || is_capped(expr->right))
146 return true;
164 expr = strip_expr(expr);
165 if (!expr)
166 return false;
167 if (get_value(expr, &sval))
168 return true;
169 if (expr->type == EXPR_BINOP)
170 return binop_capped(expr);
171 if ((expr->type == EXPR_PREOP || expr->type == EXPR_POSTOP) &&
172 (expr->op == SPECIAL_INCREMENT || expr->op == SPECIAL_DECREMENT))
173 return user_rl_capped(expr->unop);
174 state = get_state_expr(my_id, expr);
175 if (state)
176 return estate_capped(state);
177
178 if (get_user_rl(expr, &rl))
179 return false; /* uncapped user data */
180
181 return true; /* not actually user data */
182 }
183
184 static void tag_inner_struct_members(struct expression *expr, struct symbol *member)
185 {
186 struct expression *edge_member;
187 struct symbol *base = get_real_base_type(member);
188 struct symbol *tmp;
189
190 if (member->ident)
191 expr = member_expression(expr, '.', member->ident);
192
193 FOR_EACH_PTR(base->symbol_list, tmp) {
194 struct symbol *type;
195
196 type = get_real_base_type(tmp);
197 if (!type)
198 continue;
199
200 if (type->type == SYM_UNION || type->type == SYM_STRUCT) {
201 tag_inner_struct_members(expr, tmp);
202 continue;
203 }
529 if (right_type == left_type)
530 return 0;
531
532 if (!points_to_user_data(right))
533 return 0;
534
535 tag_as_user_data(expr->left);
536 return 1;
537 }
538
539 static int handle_get_user(struct expression *expr)
540 {
541 char *name;
542 int ret = 0;
543
544 name = get_macro_name(expr->pos);
545 if (!name || strcmp(name, "get_user") != 0)
546 return 0;
547
548 name = expr_to_var(expr->right);
549 if (!name || strcmp(name, "__val_gu") != 0)
550 goto free;
551 set_state_expr(my_id, expr->left, alloc_estate_whole(get_type(expr->left)));
552 ret = 1;
553 free:
554 free_string(name);
555 return ret;
556 }
557
558 static bool handle_op_assign(struct expression *expr)
559 {
560 struct expression *binop_expr;
561 struct smatch_state *state;
562 struct range_list *rl;
563
564 switch (expr->op) {
565 case SPECIAL_ADD_ASSIGN:
566 case SPECIAL_SUB_ASSIGN:
567 case SPECIAL_AND_ASSIGN:
568 case SPECIAL_MOD_ASSIGN:
569 case SPECIAL_SHL_ASSIGN:
570 case SPECIAL_SHR_ASSIGN:
571 case SPECIAL_OR_ASSIGN:
572 case SPECIAL_XOR_ASSIGN:
573 case SPECIAL_MUL_ASSIGN:
574 case SPECIAL_DIV_ASSIGN:
575 binop_expr = binop_expression(expr->left,
576 op_remove_assign(expr->op),
577 expr->right);
578 if (!get_user_rl(binop_expr, &rl))
579 return true;
580
581 rl = cast_rl(get_type(expr->left), rl);
582 state = alloc_estate_rl(rl);
583 if (user_rl_capped(binop_expr))
584 estate_set_capped(state);
585 set_state_expr(my_id, expr->left, state);
586 return true;
587 }
588 return false;
589 }
590
591 static void match_assign(struct expression *expr)
592 {
593 struct range_list *rl;
594 static struct expression *handled;
595 struct smatch_state *state;
596 struct expression *faked;
597
598 faked = get_faked_expression();
599 if (faked && faked == handled)
600 return;
601 if (is_fake_call(expr->right))
602 goto clear_old_state;
603 if (handle_get_user(expr))
604 return;
606 handled = expr;
607 set_points_to_user_data(expr->left);
608 }
609 if (handle_struct_assignment(expr))
610 return;
611
612 if (handle_op_assign(expr))
613 return;
614 if (expr->op != '=')
615 goto clear_old_state;
616
617 /* Handled by DB code */
618 if (expr->right->type == EXPR_CALL || __in_fake_parameter_assign)
619 return;
620
621 if (!get_user_rl(expr->right, &rl))
622 goto clear_old_state;
623
624 rl = cast_rl(get_type(expr->left), rl);
625 state = alloc_estate_rl(rl);
626 if (user_rl_capped(expr->right))
627 estate_set_capped(state);
628 set_state_expr(my_id, expr->left, state);
629
630 return;
631
632 clear_old_state:
633 if (get_state_expr(my_id, expr->left))
634 set_state_expr(my_id, expr->left, alloc_estate_empty());
635 }
636
637 static void handle_eq_noteq(struct expression *expr)
638 {
639 struct smatch_state *left_orig, *right_orig;
640
641 left_orig = get_state_expr(my_id, expr->left);
642 right_orig = get_state_expr(my_id, expr->right);
643
644 if (!left_orig && !right_orig)
645 return;
646 if (left_orig && right_orig)
647 return;
648
649 if (left_orig) {
650 set_true_false_states_expr(my_id, expr->left,
651 expr->op == SPECIAL_EQUAL ? alloc_estate_empty() : NULL,
652 expr->op == SPECIAL_EQUAL ? NULL : alloc_estate_empty());
653 } else {
654 set_true_false_states_expr(my_id, expr->right,
655 expr->op == SPECIAL_EQUAL ? alloc_estate_empty() : NULL,
656 expr->op == SPECIAL_EQUAL ? NULL : alloc_estate_empty());
657 }
658 }
659
660 static struct range_list *strip_negatives(struct range_list *rl)
661 {
662 sval_t min = rl_min(rl);
663 sval_t minus_one;
664 sval_t over;
665 sval_t max = sval_type_max(rl_type(rl));
666
667 minus_one.type = rl_type(rl);
668 minus_one.value = INT_MAX + 1ULL;
669 over.type = rl_type(rl);
670 over.value = -1;
671
672 if (!rl)
673 return NULL;
674
675 if (type_unsigned(rl_type(rl)) && type_bits(rl_type(rl)) > 31)
676 return remove_range(rl, over, max);
677
678 return remove_range(rl, min, minus_one);
679 }
680
681 static void handle_compare(struct expression *expr)
682 {
683 struct expression *left, *right;
684 struct range_list *left_rl = NULL;
685 struct range_list *right_rl = NULL;
686 struct range_list *user_rl;
687 struct smatch_state *capped_state;
688 struct smatch_state *left_true = NULL;
689 struct smatch_state *left_false = NULL;
690 struct smatch_state *right_true = NULL;
691 struct smatch_state *right_false = NULL;
1003 int get_user_rl_var_sym(const char *name, struct symbol *sym, struct range_list **rl)
1004 {
1005 struct smatch_state *state;
1006
1007 state = get_state(my_id, name, sym);
1008 if (state && estate_rl(state)) {
1009 *rl = estate_rl(state);
1010 return 1;
1011 }
1012 return 0;
1013 }
1014
1015 static char *get_user_rl_str(struct expression *expr, struct symbol *type)
1016 {
1017 struct range_list *rl;
1018 static char buf[64];
1019
1020 if (!get_user_rl(expr, &rl))
1021 return NULL;
1022 rl = cast_rl(type, rl);
1023 snprintf(buf, sizeof(buf), "%s%s",
1024 show_rl(rl), user_rl_capped(expr) ? "[c]" : "");
1025 return buf;
1026 }
1027
1028 static void match_call_info(struct expression *expr)
1029 {
1030 struct expression *arg;
1031 struct symbol *type;
1032 char *str;
1033 int i;
1034
1035 i = -1;
1036 FOR_EACH_PTR(expr->args, arg) {
1037 i++;
1038 type = get_arg_type(expr->fn, i);
1039 str = get_user_rl_str(arg, type);
1040 if (!str)
1041 continue;
1042
1043 sql_insert_caller_info(expr, USER_DATA, i, "$", str);
1044 } END_FOR_EACH_PTR(arg);
1076 type = get_arg_type(call->fn, param);
1077 if (type && type_bits(type) < type_bits(&ptr_ctype))
1078 return;
1079
1080 if (strcmp(sm->state->name, "") == 0)
1081 return;
1082
1083 if (strcmp(printed_name, "*$") == 0 &&
1084 is_struct_ptr(sm->sym))
1085 return;
1086
1087 state = __get_state(SMATCH_EXTRA, sm->name, sm->sym);
1088 if (!state || !estate_rl(state))
1089 rl = estate_rl(sm->state);
1090 else
1091 rl = rl_intersection(estate_rl(sm->state), estate_rl(state));
1092
1093 if (!rl)
1094 return;
1095
1096 snprintf(buf, sizeof(buf), "%s%s", show_rl(rl),
1097 estate_capped(sm->state) ? "[c]" : "");
1098 sql_insert_caller_info(call, USER_DATA, param, printed_name, buf);
1099 }
1100
1101 static void db_param_set(struct expression *expr, int param, char *key, char *value)
1102 {
1103 struct expression *arg;
1104 char *name;
1105 struct symbol *sym;
1106 struct smatch_state *state;
1107
1108 while (expr->type == EXPR_ASSIGNMENT)
1109 expr = strip_expr(expr->right);
1110 if (expr->type != EXPR_CALL)
1111 return;
1112
1113 arg = get_argument_from_call_expr(expr->args, param);
1114 if (!arg)
1115 return;
1116 name = get_variable_from_key(arg, key, &sym);
1117 if (!name || !sym)
1118 goto free;
1119
1120 state = get_state(my_id, name, sym);
1121 if (!state)
1122 goto free;
1123
1124 set_state(my_id, name, sym, alloc_estate_empty());
1125 free:
1126 free_string(name);
1127 }
1128
1129 static bool param_data_capped(const char *value)
1130 {
1131 if (strstr(value, ",c") || strstr(value, "[c"))
1132 return true;
1133 return false;
1134 }
1135
1136 static void set_param_user_data(const char *name, struct symbol *sym, char *key, char *value)
1137 {
1138 struct range_list *rl = NULL;
1139 struct smatch_state *state;
1140 struct expression *expr;
1141 struct symbol *type;
1142 char fullname[256];
1143 char *key_orig = key;
1144 bool add_star = false;
1145
1146 if (strcmp(key, "**$") == 0) {
1147 snprintf(fullname, sizeof(fullname), "**%s", name);
1148 } else {
1149 if (key[0] == '*') {
1150 add_star = true;
1151 key++;
1152 }
1153
1154 snprintf(fullname, 256, "%s%s%s", add_star ? "*" : "", name, key + 1);
1155 }
1163 * as user data or we could pass foo->bar, foo->baz as user data.
1164 * The second option is easier to implement so we do that.
1165 *
1166 */
1167 if (strcmp(key_orig, "*$") == 0) {
1168 struct symbol *tmp = type;
1169
1170 while (tmp && tmp->type == SYM_PTR)
1171 tmp = get_real_base_type(tmp);
1172
1173 if (tmp && (tmp->type == SYM_STRUCT || tmp->type == SYM_UNION)) {
1174 tag_as_user_data(symbol_expression(sym));
1175 return;
1176 }
1177 }
1178
1179 str_to_rl(type, value, &rl);
1180 state = alloc_estate_rl(rl);
1181 if (param_data_capped(value) || is_capped(expr))
1182 estate_set_capped(state);
1183 set_state(my_id, fullname, sym, state);
1184 }
1185
1186 static void set_called(const char *name, struct symbol *sym, char *key, char *value)
1187 {
1188 set_state(my_call_id, "this_function", NULL, &called);
1189 }
1190
1191 static void match_syscall_definition(struct symbol *sym)
1192 {
1193 struct symbol *arg;
1194 char *macro;
1195 char *name;
1196 int is_syscall = 0;
1197
1198 macro = get_macro_name(sym->pos);
1199 if (macro &&
1200 (strncmp("SYSCALL_DEFINE", macro, strlen("SYSCALL_DEFINE")) == 0 ||
1201 strncmp("COMPAT_SYSCALL_DEFINE", macro, strlen("COMPAT_SYSCALL_DEFINE")) == 0))
1202 is_syscall = 1;
1235 }
1236
1237 static void set_to_user_data(struct expression *expr, char *key, char *value)
1238 {
1239 struct smatch_state *state;
1240 char *name;
1241 struct symbol *sym;
1242 struct symbol *type;
1243 struct range_list *rl = NULL;
1244
1245 type = get_member_type_from_key(expr, key);
1246 name = get_variable_from_key(expr, key, &sym);
1247 if (!name || !sym)
1248 goto free;
1249
1250 call_results_to_rl(expr, type, value, &rl);
1251
1252 state = alloc_estate_rl(rl);
1253 if (param_data_capped(value))
1254 estate_set_capped(state);
1255 set_state(my_id, name, sym, state);
1256 free:
1257 free_string(name);
1258 }
1259
1260 static void returns_param_user_data(struct expression *expr, int param, char *key, char *value)
1261 {
1262 struct expression *arg;
1263 struct expression *call;
1264
1265 call = expr;
1266 while (call->type == EXPR_ASSIGNMENT)
1267 call = strip_expr(call->right);
1268 if (call->type != EXPR_CALL)
1269 return;
1270
1271 if (!we_pass_user_data(call))
1272 return;
1273
1274 if (param == -1) {
1342 if (!param_was_set_var_sym(sm->name, sm->sym))
1343 continue;
1344
1345 /* The logic here was that if we were passed in a user data then
1346 * we don't record that. It's like the difference between
1347 * param_filter and param_set. When I think about it, I'm not
1348 * sure it actually works. It's probably harmless because we
1349 * checked earlier that we're not returning a parameter...
1350 * Let's mark this as a TODO.
1351 */
1352 start_state = get_state_stree(start_states, my_id, sm->name, sm->sym);
1353 if (start_state && rl_equiv(estate_rl(sm->state), estate_rl(start_state)))
1354 continue;
1355
1356 param_name = get_param_name(sm);
1357 if (!param_name)
1358 continue;
1359 if (strcmp(param_name, "$") == 0) /* The -1 param is handled after the loop */
1360 continue;
1361
1362 snprintf(buf, sizeof(buf), "%s%s",
1363 show_rl(estate_rl(sm->state)),
1364 estate_capped(sm->state) ? "[c]" : "");
1365 sql_insert_return_states(return_id, return_ranges,
1366 func_gets_user_data ? USER_DATA_SET : USER_DATA,
1367 param, param_name, buf);
1368 } END_FOR_EACH_SM(sm);
1369
1370 /* This if for "return foo;" where "foo->bar" is user data. */
1371 FOR_EACH_MY_SM(my_id, __get_cur_stree(), sm) {
1372 if (!ret_sym)
1373 break;
1374 if (ret_sym != sm->sym)
1375 continue;
1376
1377 param_name = state_name_to_param_name(sm->name, return_str);
1378 if (!param_name)
1379 continue;
1380 if (strcmp(param_name, "$") == 0)
1381 return_found = true;
1382 if (strcmp(param_name, "*$") == 0)
1383 pointed_at_found = true;
1384 snprintf(buf, sizeof(buf), "%s%s",
1385 show_rl(estate_rl(sm->state)),
1386 estate_capped(sm->state) ? "[c]" : "");
1387 sql_insert_return_states(return_id, return_ranges,
1388 func_gets_user_data ? USER_DATA_SET : USER_DATA,
1389 -1, param_name, buf);
1390 } END_FOR_EACH_SM(sm);
1391
1392 /* This if for "return ntohl(foo);" */
1393 if (!return_found && get_user_rl(expr, &rl)) {
1394 snprintf(buf, sizeof(buf), "%s%s",
1395 show_rl(rl), user_rl_capped(expr) ? "[c]" : "");
1396 sql_insert_return_states(return_id, return_ranges,
1397 func_gets_user_data ? USER_DATA_SET : USER_DATA,
1398 -1, "$", buf);
1399 }
1400
1401 /*
1402 * This is to handle things like return skb->data where we don't set a
1403 * state for that.
1404 */
1405 if (!pointed_at_found && points_to_user_data(expr)) {
1406 sql_insert_return_states(return_id, return_ranges,
1407 (is_skb_data(expr) || func_gets_user_data) ?
1408 USER_DATA_SET : USER_DATA,
1409 -1, "*$", "s64min-s64max");
1410 }
1411
1412 free_string(return_str);
1413 }
1414
1415 static void returns_param_capped(struct expression *expr, int param, char *key, char *value)
1495 select_return_states_hook(PARAM_SET, &db_param_set);
1496 add_hook(&match_condition, CONDITION_HOOK);
1497
1498 add_hook(&match_call_info, FUNCTION_CALL_HOOK);
1499 add_member_info_callback(my_id, struct_member_callback);
1500 select_caller_info_hook(set_param_user_data, USER_DATA);
1501 select_return_states_hook(USER_DATA, &returns_param_user_data);
1502 select_return_states_hook(USER_DATA_SET, &returns_param_user_data_set);
1503 select_return_states_hook(CAPPED_DATA, &returns_param_capped);
1504 add_split_return_callback(¶m_set_to_user_data);
1505 }
1506
1507 void register_kernel_user_data2(int id)
1508 {
1509 my_call_id = id;
1510
1511 if (option_project != PROJ_KERNEL)
1512 return;
1513 select_caller_info_hook(set_called, INTERNAL);
1514 }
|
66 free_stree(&start_states);
67 }
68
69 static void match_save_states(struct expression *expr)
70 {
71 push_stree(&saved_stack, start_states);
72 start_states = NULL;
73 }
74
75 static void match_restore_states(struct expression *expr)
76 {
77 free_stree(&start_states);
78 start_states = pop_stree(&saved_stack);
79 }
80
81 static struct smatch_state *empty_state(struct sm_state *sm)
82 {
83 return alloc_estate_empty();
84 }
85
86 static void pre_merge_hook(struct sm_state *cur, struct sm_state *other)
87 {
88 struct smatch_state *user = cur->state;
89 struct smatch_state *extra;
90 struct smatch_state *state;
91 struct range_list *rl;
92
93 extra = __get_state(SMATCH_EXTRA, cur->name, cur->sym);
94 if (!extra)
95 return;
96 rl = rl_intersection(estate_rl(user), estate_rl(extra));
97 state = alloc_estate_rl(clone_rl(rl));
98 if (estate_capped(user) || is_capped_var_sym(cur->name, cur->sym))
99 estate_set_capped(state);
100 if (estate_treat_untagged(user))
101 estate_set_treat_untagged(state);
102 set_state(my_id, cur->name, cur->sym, state);
103 }
104
105 static void extra_nomod_hook(const char *name, struct symbol *sym, struct expression *expr, struct smatch_state *state)
106 {
107 struct smatch_state *user, *new;
108 struct range_list *rl;
109
110 user = __get_state(my_id, name, sym);
111 if (!user)
112 return;
113 rl = rl_intersection(estate_rl(user), estate_rl(state));
114 if (rl_equiv(rl, estate_rl(user)))
115 return;
116 new = alloc_estate_rl(rl);
117 if (estate_capped(user))
118 estate_set_capped(new);
119 if (estate_treat_untagged(user))
120 estate_set_treat_untagged(new);
121 set_state(my_id, name, sym, new);
122 }
123
124 static bool binop_capped(struct expression *expr)
125 {
126 struct range_list *left_rl;
127 int comparison;
128
129 if (expr->op == '-' && get_user_rl(expr->left, &left_rl)) {
130 if (user_rl_capped(expr->left))
131 return true;
132 comparison = get_comparison(expr->left, expr->right);
133 if (comparison && show_special(comparison)[0] == '>')
134 return true;
135 return false;
136 }
137
138 if (expr->op == '&' || expr->op == '%') {
139 if (is_capped(expr->left) || is_capped(expr->right))
140 return true;
158 expr = strip_expr(expr);
159 if (!expr)
160 return false;
161 if (get_value(expr, &sval))
162 return true;
163 if (expr->type == EXPR_BINOP)
164 return binop_capped(expr);
165 if ((expr->type == EXPR_PREOP || expr->type == EXPR_POSTOP) &&
166 (expr->op == SPECIAL_INCREMENT || expr->op == SPECIAL_DECREMENT))
167 return user_rl_capped(expr->unop);
168 state = get_state_expr(my_id, expr);
169 if (state)
170 return estate_capped(state);
171
172 if (get_user_rl(expr, &rl))
173 return false; /* uncapped user data */
174
175 return true; /* not actually user data */
176 }
177
178 bool user_rl_treat_untagged(struct expression *expr)
179 {
180 struct smatch_state *state;
181 struct range_list *rl;
182 sval_t sval;
183
184 expr = strip_expr(expr);
185 if (!expr)
186 return false;
187 if (get_value(expr, &sval))
188 return true;
189
190 state = get_state_expr(my_id, expr);
191 if (state)
192 return estate_treat_untagged(state);
193
194 if (get_user_rl(expr, &rl))
195 return false; /* uncapped user data */
196
197 return true; /* not actually user data */
198 }
199
200 static void tag_inner_struct_members(struct expression *expr, struct symbol *member)
201 {
202 struct expression *edge_member;
203 struct symbol *base = get_real_base_type(member);
204 struct symbol *tmp;
205
206 if (member->ident)
207 expr = member_expression(expr, '.', member->ident);
208
209 FOR_EACH_PTR(base->symbol_list, tmp) {
210 struct symbol *type;
211
212 type = get_real_base_type(tmp);
213 if (!type)
214 continue;
215
216 if (type->type == SYM_UNION || type->type == SYM_STRUCT) {
217 tag_inner_struct_members(expr, tmp);
218 continue;
219 }
545 if (right_type == left_type)
546 return 0;
547
548 if (!points_to_user_data(right))
549 return 0;
550
551 tag_as_user_data(expr->left);
552 return 1;
553 }
554
555 static int handle_get_user(struct expression *expr)
556 {
557 char *name;
558 int ret = 0;
559
560 name = get_macro_name(expr->pos);
561 if (!name || strcmp(name, "get_user") != 0)
562 return 0;
563
564 name = expr_to_var(expr->right);
565 if (!name || (strcmp(name, "__val_gu") != 0 && strcmp(name, "__gu_val") != 0))
566 goto free;
567 set_state_expr(my_id, expr->left, alloc_estate_whole(get_type(expr->left)));
568 ret = 1;
569 free:
570 free_string(name);
571 return ret;
572 }
573
574 static bool handle_op_assign(struct expression *expr)
575 {
576 struct expression *binop_expr;
577 struct smatch_state *state;
578 struct range_list *rl;
579
580 switch (expr->op) {
581 case SPECIAL_ADD_ASSIGN:
582 case SPECIAL_SUB_ASSIGN:
583 case SPECIAL_AND_ASSIGN:
584 case SPECIAL_MOD_ASSIGN:
585 case SPECIAL_SHL_ASSIGN:
586 case SPECIAL_SHR_ASSIGN:
587 case SPECIAL_OR_ASSIGN:
588 case SPECIAL_XOR_ASSIGN:
589 case SPECIAL_MUL_ASSIGN:
590 case SPECIAL_DIV_ASSIGN:
591 binop_expr = binop_expression(expr->left,
592 op_remove_assign(expr->op),
593 expr->right);
594 if (!get_user_rl(binop_expr, &rl))
595 return true;
596
597 rl = cast_rl(get_type(expr->left), rl);
598 state = alloc_estate_rl(rl);
599 if (user_rl_capped(binop_expr))
600 estate_set_capped(state);
601 if (user_rl_treat_untagged(expr->left))
602 estate_set_treat_untagged(state);
603 set_state_expr(my_id, expr->left, state);
604 return true;
605 }
606 return false;
607 }
608
609 static void match_assign(struct expression *expr)
610 {
611 struct range_list *rl;
612 static struct expression *handled;
613 struct smatch_state *state;
614 struct expression *faked;
615
616 faked = get_faked_expression();
617 if (faked && faked == handled)
618 return;
619 if (is_fake_call(expr->right))
620 goto clear_old_state;
621 if (handle_get_user(expr))
622 return;
624 handled = expr;
625 set_points_to_user_data(expr->left);
626 }
627 if (handle_struct_assignment(expr))
628 return;
629
630 if (handle_op_assign(expr))
631 return;
632 if (expr->op != '=')
633 goto clear_old_state;
634
635 /* Handled by DB code */
636 if (expr->right->type == EXPR_CALL || __in_fake_parameter_assign)
637 return;
638
639 if (!get_user_rl(expr->right, &rl))
640 goto clear_old_state;
641
642 rl = cast_rl(get_type(expr->left), rl);
643 state = alloc_estate_rl(rl);
644
645 if (user_rl_capped(expr->right))
646 estate_set_capped(state);
647 if (user_rl_treat_untagged(expr->right))
648 estate_set_treat_untagged(state);
649 set_state_expr(my_id, expr->left, state);
650
651 return;
652
653 clear_old_state:
654 if (get_state_expr(my_id, expr->left))
655 set_state_expr(my_id, expr->left, alloc_estate_empty());
656 }
657
658 static void handle_eq_noteq(struct expression *expr)
659 {
660 struct smatch_state *left_orig, *right_orig;
661
662 left_orig = get_state_expr(my_id, expr->left);
663 right_orig = get_state_expr(my_id, expr->right);
664
665 if (!left_orig && !right_orig)
666 return;
667 if (left_orig && right_orig)
668 return;
669
670 if (left_orig) {
671 set_true_false_states_expr(my_id, expr->left,
672 expr->op == SPECIAL_EQUAL ? alloc_estate_empty() : NULL,
673 expr->op == SPECIAL_EQUAL ? NULL : alloc_estate_empty());
674 } else {
675 set_true_false_states_expr(my_id, expr->right,
676 expr->op == SPECIAL_EQUAL ? alloc_estate_empty() : NULL,
677 expr->op == SPECIAL_EQUAL ? NULL : alloc_estate_empty());
678 }
679 }
680
681 static struct range_list *strip_negatives(struct range_list *rl)
682 {
683 sval_t min = rl_min(rl);
684 sval_t minus_one = { .type = rl_type(rl), .value = -1 };
685 sval_t over = { .type = rl_type(rl), .value = INT_MAX + 1ULL };
686 sval_t max = sval_type_max(rl_type(rl));
687
688 if (!rl)
689 return NULL;
690
691 if (type_unsigned(rl_type(rl)) && type_bits(rl_type(rl)) > 31)
692 return remove_range(rl, over, max);
693
694 return remove_range(rl, min, minus_one);
695 }
696
697 static void handle_compare(struct expression *expr)
698 {
699 struct expression *left, *right;
700 struct range_list *left_rl = NULL;
701 struct range_list *right_rl = NULL;
702 struct range_list *user_rl;
703 struct smatch_state *capped_state;
704 struct smatch_state *left_true = NULL;
705 struct smatch_state *left_false = NULL;
706 struct smatch_state *right_true = NULL;
707 struct smatch_state *right_false = NULL;
1019 int get_user_rl_var_sym(const char *name, struct symbol *sym, struct range_list **rl)
1020 {
1021 struct smatch_state *state;
1022
1023 state = get_state(my_id, name, sym);
1024 if (state && estate_rl(state)) {
1025 *rl = estate_rl(state);
1026 return 1;
1027 }
1028 return 0;
1029 }
1030
1031 static char *get_user_rl_str(struct expression *expr, struct symbol *type)
1032 {
1033 struct range_list *rl;
1034 static char buf[64];
1035
1036 if (!get_user_rl(expr, &rl))
1037 return NULL;
1038 rl = cast_rl(type, rl);
1039 snprintf(buf, sizeof(buf), "%s%s%s",
1040 show_rl(rl),
1041 user_rl_capped(expr) ? "[c]" : "",
1042 user_rl_treat_untagged(expr) ? "[u]" : "");
1043 return buf;
1044 }
1045
1046 static void match_call_info(struct expression *expr)
1047 {
1048 struct expression *arg;
1049 struct symbol *type;
1050 char *str;
1051 int i;
1052
1053 i = -1;
1054 FOR_EACH_PTR(expr->args, arg) {
1055 i++;
1056 type = get_arg_type(expr->fn, i);
1057 str = get_user_rl_str(arg, type);
1058 if (!str)
1059 continue;
1060
1061 sql_insert_caller_info(expr, USER_DATA, i, "$", str);
1062 } END_FOR_EACH_PTR(arg);
1094 type = get_arg_type(call->fn, param);
1095 if (type && type_bits(type) < type_bits(&ptr_ctype))
1096 return;
1097
1098 if (strcmp(sm->state->name, "") == 0)
1099 return;
1100
1101 if (strcmp(printed_name, "*$") == 0 &&
1102 is_struct_ptr(sm->sym))
1103 return;
1104
1105 state = __get_state(SMATCH_EXTRA, sm->name, sm->sym);
1106 if (!state || !estate_rl(state))
1107 rl = estate_rl(sm->state);
1108 else
1109 rl = rl_intersection(estate_rl(sm->state), estate_rl(state));
1110
1111 if (!rl)
1112 return;
1113
1114 snprintf(buf, sizeof(buf), "%s%s%s", show_rl(rl),
1115 estate_capped(sm->state) ? "[c]" : "",
1116 estate_treat_untagged(sm->state) ? "[u]" : "");
1117 sql_insert_caller_info(call, USER_DATA, param, printed_name, buf);
1118 }
1119
1120 static void db_param_set(struct expression *expr, int param, char *key, char *value)
1121 {
1122 struct expression *arg;
1123 char *name;
1124 struct symbol *sym;
1125 struct smatch_state *state;
1126
1127 while (expr->type == EXPR_ASSIGNMENT)
1128 expr = strip_expr(expr->right);
1129 if (expr->type != EXPR_CALL)
1130 return;
1131
1132 arg = get_argument_from_call_expr(expr->args, param);
1133 if (!arg)
1134 return;
1135 name = get_variable_from_key(arg, key, &sym);
1136 if (!name || !sym)
1137 goto free;
1138
1139 state = get_state(my_id, name, sym);
1140 if (!state)
1141 goto free;
1142
1143 set_state(my_id, name, sym, alloc_estate_empty());
1144 free:
1145 free_string(name);
1146 }
1147
1148 static bool param_data_capped(const char *value)
1149 {
1150 if (strstr(value, ",c") || strstr(value, "[c"))
1151 return true;
1152 return false;
1153 }
1154
1155 static bool param_data_treat_untagged(const char *value)
1156 {
1157 if (strstr(value, ",u") || strstr(value, "[u"))
1158 return true;
1159 return false;
1160 }
1161
1162 static void set_param_user_data(const char *name, struct symbol *sym, char *key, char *value)
1163 {
1164 struct range_list *rl = NULL;
1165 struct smatch_state *state;
1166 struct expression *expr;
1167 struct symbol *type;
1168 char fullname[256];
1169 char *key_orig = key;
1170 bool add_star = false;
1171
1172 if (strcmp(key, "**$") == 0) {
1173 snprintf(fullname, sizeof(fullname), "**%s", name);
1174 } else {
1175 if (key[0] == '*') {
1176 add_star = true;
1177 key++;
1178 }
1179
1180 snprintf(fullname, 256, "%s%s%s", add_star ? "*" : "", name, key + 1);
1181 }
1189 * as user data or we could pass foo->bar, foo->baz as user data.
1190 * The second option is easier to implement so we do that.
1191 *
1192 */
1193 if (strcmp(key_orig, "*$") == 0) {
1194 struct symbol *tmp = type;
1195
1196 while (tmp && tmp->type == SYM_PTR)
1197 tmp = get_real_base_type(tmp);
1198
1199 if (tmp && (tmp->type == SYM_STRUCT || tmp->type == SYM_UNION)) {
1200 tag_as_user_data(symbol_expression(sym));
1201 return;
1202 }
1203 }
1204
1205 str_to_rl(type, value, &rl);
1206 state = alloc_estate_rl(rl);
1207 if (param_data_capped(value) || is_capped(expr))
1208 estate_set_capped(state);
1209 if (param_data_treat_untagged(value) || sym->ctype.as == 5)
1210 estate_set_treat_untagged(state);
1211 set_state(my_id, fullname, sym, state);
1212 }
1213
1214 static void set_called(const char *name, struct symbol *sym, char *key, char *value)
1215 {
1216 set_state(my_call_id, "this_function", NULL, &called);
1217 }
1218
1219 static void match_syscall_definition(struct symbol *sym)
1220 {
1221 struct symbol *arg;
1222 char *macro;
1223 char *name;
1224 int is_syscall = 0;
1225
1226 macro = get_macro_name(sym->pos);
1227 if (macro &&
1228 (strncmp("SYSCALL_DEFINE", macro, strlen("SYSCALL_DEFINE")) == 0 ||
1229 strncmp("COMPAT_SYSCALL_DEFINE", macro, strlen("COMPAT_SYSCALL_DEFINE")) == 0))
1230 is_syscall = 1;
1263 }
1264
1265 static void set_to_user_data(struct expression *expr, char *key, char *value)
1266 {
1267 struct smatch_state *state;
1268 char *name;
1269 struct symbol *sym;
1270 struct symbol *type;
1271 struct range_list *rl = NULL;
1272
1273 type = get_member_type_from_key(expr, key);
1274 name = get_variable_from_key(expr, key, &sym);
1275 if (!name || !sym)
1276 goto free;
1277
1278 call_results_to_rl(expr, type, value, &rl);
1279
1280 state = alloc_estate_rl(rl);
1281 if (param_data_capped(value))
1282 estate_set_capped(state);
1283 if (param_data_treat_untagged(value))
1284 estate_set_treat_untagged(state);
1285 set_state(my_id, name, sym, state);
1286 free:
1287 free_string(name);
1288 }
1289
1290 static void returns_param_user_data(struct expression *expr, int param, char *key, char *value)
1291 {
1292 struct expression *arg;
1293 struct expression *call;
1294
1295 call = expr;
1296 while (call->type == EXPR_ASSIGNMENT)
1297 call = strip_expr(call->right);
1298 if (call->type != EXPR_CALL)
1299 return;
1300
1301 if (!we_pass_user_data(call))
1302 return;
1303
1304 if (param == -1) {
1372 if (!param_was_set_var_sym(sm->name, sm->sym))
1373 continue;
1374
1375 /* The logic here was that if we were passed in a user data then
1376 * we don't record that. It's like the difference between
1377 * param_filter and param_set. When I think about it, I'm not
1378 * sure it actually works. It's probably harmless because we
1379 * checked earlier that we're not returning a parameter...
1380 * Let's mark this as a TODO.
1381 */
1382 start_state = get_state_stree(start_states, my_id, sm->name, sm->sym);
1383 if (start_state && rl_equiv(estate_rl(sm->state), estate_rl(start_state)))
1384 continue;
1385
1386 param_name = get_param_name(sm);
1387 if (!param_name)
1388 continue;
1389 if (strcmp(param_name, "$") == 0) /* The -1 param is handled after the loop */
1390 continue;
1391
1392 snprintf(buf, sizeof(buf), "%s%s%s",
1393 show_rl(estate_rl(sm->state)),
1394 estate_capped(sm->state) ? "[c]" : "",
1395 estate_treat_untagged(sm->state) ? "[u]" : "");
1396 sql_insert_return_states(return_id, return_ranges,
1397 func_gets_user_data ? USER_DATA_SET : USER_DATA,
1398 param, param_name, buf);
1399 } END_FOR_EACH_SM(sm);
1400
1401 /* This if for "return foo;" where "foo->bar" is user data. */
1402 FOR_EACH_MY_SM(my_id, __get_cur_stree(), sm) {
1403 if (!ret_sym)
1404 break;
1405 if (ret_sym != sm->sym)
1406 continue;
1407
1408 param_name = state_name_to_param_name(sm->name, return_str);
1409 if (!param_name)
1410 continue;
1411 if (strcmp(param_name, "$") == 0)
1412 return_found = true;
1413 if (strcmp(param_name, "*$") == 0)
1414 pointed_at_found = true;
1415 snprintf(buf, sizeof(buf), "%s%s%s",
1416 show_rl(estate_rl(sm->state)),
1417 estate_capped(sm->state) ? "[c]" : "",
1418 estate_treat_untagged(sm->state) ? "[u]" : "");
1419 sql_insert_return_states(return_id, return_ranges,
1420 func_gets_user_data ? USER_DATA_SET : USER_DATA,
1421 -1, param_name, buf);
1422 } END_FOR_EACH_SM(sm);
1423
1424 /* This if for "return ntohl(foo);" */
1425 if (!return_found && get_user_rl(expr, &rl)) {
1426 snprintf(buf, sizeof(buf), "%s%s%s",
1427 show_rl(rl),
1428 user_rl_capped(expr) ? "[c]" : "",
1429 user_rl_treat_untagged(expr) ? "[u]" : "");
1430 sql_insert_return_states(return_id, return_ranges,
1431 func_gets_user_data ? USER_DATA_SET : USER_DATA,
1432 -1, "$", buf);
1433 }
1434
1435 /*
1436 * This is to handle things like return skb->data where we don't set a
1437 * state for that.
1438 */
1439 if (!pointed_at_found && points_to_user_data(expr)) {
1440 sql_insert_return_states(return_id, return_ranges,
1441 (is_skb_data(expr) || func_gets_user_data) ?
1442 USER_DATA_SET : USER_DATA,
1443 -1, "*$", "s64min-s64max");
1444 }
1445
1446 free_string(return_str);
1447 }
1448
1449 static void returns_param_capped(struct expression *expr, int param, char *key, char *value)
1529 select_return_states_hook(PARAM_SET, &db_param_set);
1530 add_hook(&match_condition, CONDITION_HOOK);
1531
1532 add_hook(&match_call_info, FUNCTION_CALL_HOOK);
1533 add_member_info_callback(my_id, struct_member_callback);
1534 select_caller_info_hook(set_param_user_data, USER_DATA);
1535 select_return_states_hook(USER_DATA, &returns_param_user_data);
1536 select_return_states_hook(USER_DATA_SET, &returns_param_user_data_set);
1537 select_return_states_hook(CAPPED_DATA, &returns_param_capped);
1538 add_split_return_callback(¶m_set_to_user_data);
1539 }
1540
1541 void register_kernel_user_data2(int id)
1542 {
1543 my_call_id = id;
1544
1545 if (option_project != PROJ_KERNEL)
1546 return;
1547 select_caller_info_hook(set_called, INTERNAL);
1548 }
1549
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