Print this page
11506 smatch resync
@@ -30,11 +30,11 @@
static int my_call_id;
STATE(called);
static bool func_gets_user_data;
-static const char * kstr_funcs[] = {
+static const char *kstr_funcs[] = {
"kstrtoull", "kstrtoll", "kstrtoul", "kstrtol", "kstrtouint",
"kstrtoint", "kstrtou64", "kstrtos64", "kstrtou32", "kstrtos32",
"kstrtou16", "kstrtos16", "kstrtou8", "kstrtos8", "kstrtoull_from_user"
"kstrtoll_from_user", "kstrtoul_from_user", "kstrtol_from_user",
"kstrtouint_from_user", "kstrtoint_from_user", "kstrtou16_from_user",
@@ -43,14 +43,17 @@
"kstrtos32_from_user",
};
static const char *returns_user_data[] = {
"simple_strtol", "simple_strtoll", "simple_strtoul", "simple_strtoull",
- "kvm_register_read", "nlmsg_data", "nla_data", "memdup_user",
- "kmap_atomic", "skb_network_header",
+ "kvm_register_read",
};
+static const char *returns_pointer_to_user_data[] = {
+ "nlmsg_data", "nla_data", "memdup_user", "kmap_atomic", "skb_network_header",
+};
+
static void set_points_to_user_data(struct expression *expr);
static struct stree *start_states;
static struct stree_stack *saved_stack;
static void save_start_states(struct statement *stmt)
@@ -82,65 +85,104 @@
static void pre_merge_hook(struct sm_state *sm)
{
struct smatch_state *user;
struct smatch_state *extra;
+ struct smatch_state *state;
struct range_list *rl;
sval_t dummy;
sval_t sval_100;
sval_100.value = 100;
sval_100.type = &int_ctype;
- user = get_state(my_id, sm->name, sm->sym);
- if (!user)
+ user = __get_state(my_id, sm->name, sm->sym);
+ if (!user || !estate_rl(user))
return;
- if (!__in_function_def && !estate_rl(sm->state)) {
- /*
- * If the one side is capped and the other side is empty then
- * let's just mark it as not-user data because the information
- * isn't going to be useful. How this looks is:
- *
- * if (user_var > trusted)
- * user_var = trusted; <-- empty state
- * else
- * <-- capped
- *
- * The problem is that sometimes things are capped to a literal
- * and we'd like to keep the state in that case... Ugh. I've
- * added a check which assumes that everything less than 100 is
- * probably capped against a literal.
- *
- */
- if (is_capped_var_sym(sm->name, sm->sym) &&
- sval_cmp(estate_max(user), sval_100) > 0)
- set_state(my_id, sm->name, sm->sym, alloc_estate_empty());
+ extra = __get_state(SMATCH_EXTRA, sm->name, sm->sym);
+ if (!extra)
return;
- }
- extra = get_state(SMATCH_EXTRA, sm->name, sm->sym);
- if (!extra || !estate_rl(extra))
- return;
rl = rl_intersection(estate_rl(user), estate_rl(extra));
if (rl_to_sval(rl, &dummy))
rl = NULL;
- set_state(my_id, sm->name, sm->sym, alloc_estate_rl(clone_rl(rl)));
+ state = alloc_estate_rl(clone_rl(rl));
+ if (estate_capped(user) || is_capped_var_sym(sm->name, sm->sym))
+ estate_set_capped(state);
+ set_state(my_id, sm->name, sm->sym, state);
}
static void extra_nomod_hook(const char *name, struct symbol *sym, struct expression *expr, struct smatch_state *state)
{
- struct smatch_state *user;
+ struct smatch_state *user, *new;
struct range_list *rl;
- user = get_state(my_id, name, sym);
+ user = __get_state(my_id, name, sym);
if (!user)
return;
rl = rl_intersection(estate_rl(user), estate_rl(state));
if (rl_equiv(rl, estate_rl(user)))
return;
- set_state(my_id, name, sym, alloc_estate_rl(rl));
+ new = alloc_estate_rl(rl);
+ if (estate_capped(user))
+ estate_set_capped(new);
+ set_state(my_id, name, sym, new);
}
+static bool binop_capped(struct expression *expr)
+{
+ struct range_list *left_rl;
+ int comparison;
+
+ if (expr->op == '-' && get_user_rl(expr->left, &left_rl)) {
+ if (user_rl_capped(expr->left))
+ return true;
+ comparison = get_comparison(expr->left, expr->right);
+ if (comparison && show_special(comparison)[0] == '>')
+ return true;
+ return false;
+ }
+
+ if (expr->op == '&' || expr->op == '%') {
+ if (is_capped(expr->left) || is_capped(expr->right))
+ return true;
+ if (user_rl_capped(expr->left) || user_rl_capped(expr->right))
+ return true;
+ return false;
+ }
+
+ if (user_rl_capped(expr->left) &&
+ user_rl_capped(expr->right))
+ return true;
+ return false;
+}
+
+bool user_rl_capped(struct expression *expr)
+{
+ struct smatch_state *state;
+ struct range_list *rl;
+ sval_t sval;
+
+ expr = strip_expr(expr);
+ if (!expr)
+ return false;
+ if (get_value(expr, &sval))
+ return true;
+ if (expr->type == EXPR_BINOP)
+ return binop_capped(expr);
+ if ((expr->type == EXPR_PREOP || expr->type == EXPR_POSTOP) &&
+ (expr->op == SPECIAL_INCREMENT || expr->op == SPECIAL_DECREMENT))
+ return user_rl_capped(expr->unop);
+ state = get_state_expr(my_id, expr);
+ if (state)
+ return estate_capped(state);
+
+ if (get_user_rl(expr, &rl))
+ return false; /* uncapped user data */
+
+ return true; /* not actually user data */
+}
+
static void tag_inner_struct_members(struct expression *expr, struct symbol *member)
{
struct expression *edge_member;
struct symbol *base = get_real_base_type(member);
struct symbol *tmp;
@@ -345,10 +387,26 @@
return 0;
return 1;
}
+static bool is_points_to_user_data_fn(struct expression *expr)
+{
+ int i;
+
+ expr = strip_expr(expr);
+ if (expr->type != EXPR_CALL || expr->fn->type != EXPR_SYMBOL ||
+ !expr->fn->symbol)
+ return false;
+ expr = expr->fn;
+ for (i = 0; i < ARRAY_SIZE(returns_pointer_to_user_data); i++) {
+ if (sym_name_is(returns_pointer_to_user_data[i], expr))
+ return true;
+ }
+ return false;
+}
+
static int get_rl_from_function(struct expression *expr, struct range_list **rl)
{
int i;
if (expr->type != EXPR_CALL || expr->fn->type != EXPR_SYMBOL ||
@@ -376,10 +434,12 @@
expr = strip_expr(expr);
if (!expr)
return 0;
if (is_skb_data(expr))
return 1;
+ if (is_points_to_user_data_fn(expr))
+ return 1;
if (get_rl_from_function(expr, &rl))
return 1;
if (expr->type == EXPR_BINOP && expr->op == '+') {
if (points_to_user_data(expr->left))
@@ -391,11 +451,11 @@
name = expr_to_var_sym(expr, &sym);
if (!name || !sym)
goto free;
snprintf(buf, sizeof(buf), "*%s", name);
- state = get_state(my_id, buf, sym);
+ state = __get_state(my_id, buf, sym);
if (state && estate_rl(state))
ret = 1;
free:
free_string(name);
return ret;
@@ -404,16 +464,22 @@
static void set_points_to_user_data(struct expression *expr)
{
char *name;
struct symbol *sym;
char buf[256];
+ struct symbol *type;
name = expr_to_var_sym(expr, &sym);
if (!name || !sym)
goto free;
snprintf(buf, sizeof(buf), "*%s", name);
- set_state(my_id, buf, sym, alloc_estate_whole(&llong_ctype));
+ type = get_type(expr);
+ if (type && type->type == SYM_PTR)
+ type = get_real_base_type(type);
+ if (!type || type->type != SYM_BASETYPE)
+ type = &llong_ctype;
+ set_state(my_id, buf, sym, alloc_estate_whole(type));
free:
free_string(name);
}
static int comes_from_skb_data(struct expression *expr)
@@ -487,28 +553,81 @@
free:
free_string(name);
return ret;
}
+static bool handle_op_assign(struct expression *expr)
+{
+ struct expression *binop_expr;
+ struct smatch_state *state;
+ struct range_list *rl;
+
+ switch (expr->op) {
+ case SPECIAL_ADD_ASSIGN:
+ case SPECIAL_SUB_ASSIGN:
+ case SPECIAL_AND_ASSIGN:
+ case SPECIAL_MOD_ASSIGN:
+ case SPECIAL_SHL_ASSIGN:
+ case SPECIAL_SHR_ASSIGN:
+ case SPECIAL_OR_ASSIGN:
+ case SPECIAL_XOR_ASSIGN:
+ case SPECIAL_MUL_ASSIGN:
+ case SPECIAL_DIV_ASSIGN:
+ binop_expr = binop_expression(expr->left,
+ op_remove_assign(expr->op),
+ expr->right);
+ if (!get_user_rl(binop_expr, &rl))
+ return true;
+
+ rl = cast_rl(get_type(expr->left), rl);
+ state = alloc_estate_rl(rl);
+ if (user_rl_capped(binop_expr))
+ estate_set_capped(state);
+ set_state_expr(my_id, expr->left, state);
+ return true;
+ }
+ return false;
+}
+
static void match_assign(struct expression *expr)
{
struct range_list *rl;
+ static struct expression *handled;
+ struct smatch_state *state;
+ struct expression *faked;
+ faked = get_faked_expression();
+ if (faked && faked == handled)
+ return;
if (is_fake_call(expr->right))
goto clear_old_state;
if (handle_get_user(expr))
return;
- if (points_to_user_data(expr->right))
+ if (points_to_user_data(expr->right)) {
+ handled = expr;
set_points_to_user_data(expr->left);
+ }
if (handle_struct_assignment(expr))
return;
+ if (handle_op_assign(expr))
+ return;
+ if (expr->op != '=')
+ goto clear_old_state;
+
+ /* Handled by DB code */
+ if (expr->right->type == EXPR_CALL || __in_fake_parameter_assign)
+ return;
+
if (!get_user_rl(expr->right, &rl))
goto clear_old_state;
rl = cast_rl(get_type(expr->left), rl);
- set_state_expr(my_id, expr->left, alloc_estate_rl(rl));
+ state = alloc_estate_rl(rl);
+ if (user_rl_capped(expr->right))
+ estate_set_capped(state);
+ set_state_expr(my_id, expr->left, state);
return;
clear_old_state:
if (get_state_expr(my_id, expr->left))
@@ -536,65 +655,119 @@
expr->op == SPECIAL_EQUAL ? alloc_estate_empty() : NULL,
expr->op == SPECIAL_EQUAL ? NULL : alloc_estate_empty());
}
}
-static void handle_unsigned_lt_gt(struct expression *expr)
+static struct range_list *strip_negatives(struct range_list *rl)
{
+ sval_t min = rl_min(rl);
+ sval_t minus_one;
+ sval_t over;
+ sval_t max = sval_type_max(rl_type(rl));
+
+ minus_one.type = rl_type(rl);
+ minus_one.value = INT_MAX + 1ULL;
+ over.type = rl_type(rl);
+ over.value = -1;
+
+ if (!rl)
+ return NULL;
+
+ if (type_unsigned(rl_type(rl)) && type_bits(rl_type(rl)) > 31)
+ return remove_range(rl, over, max);
+
+ return remove_range(rl, min, minus_one);
+}
+
+static void handle_compare(struct expression *expr)
+{
+ struct expression *left, *right;
+ struct range_list *left_rl = NULL;
+ struct range_list *right_rl = NULL;
+ struct range_list *user_rl;
+ struct smatch_state *capped_state;
+ struct smatch_state *left_true = NULL;
+ struct smatch_state *left_false = NULL;
+ struct smatch_state *right_true = NULL;
+ struct smatch_state *right_false = NULL;
struct symbol *type;
- struct range_list *left;
- struct range_list *right;
- struct range_list *non_negative;
- sval_t min, minus_one;
+ sval_t sval;
+ left = strip_expr(expr->left);
+ right = strip_expr(expr->right);
+
+ while (left->type == EXPR_ASSIGNMENT)
+ left = strip_expr(left->left);
+
/*
- * conditions are mostly handled by smatch_extra.c. The special case
- * here is that say you have if (user_int < unknown_u32) {
- * In Smatch extra we say that, We have no idea what value
- * unknown_u32 is so the only thin we can say for sure is that
- * user_int is not -1 (UINT_MAX). But in check_user_data2.c we should
- * assume that unless unknown_u32 is user data, it's probably less than
- * INT_MAX.
+ * Conditions are mostly handled by smatch_extra.c, but there are some
+ * times where the exact values are not known so we can't do that.
*
+ * Normally, we might consider using smatch_capped.c to supliment smatch
+ * extra but that doesn't work when we merge unknown uncapped kernel
+ * data with unknown capped user data. The result is uncapped user
+ * data. We need to keep it separate and say that the user data is
+ * capped. In the past, I would have marked this as just regular
+ * kernel data (not user data) but we can't do that these days because
+ * we need to track user data for Spectre.
+ *
+ * The other situation which we have to handle is when we do have an
+ * int and we compare against an unknown unsigned kernel variable. In
+ * that situation we assume that the kernel data is less than INT_MAX.
+ * Otherwise then we get all sorts of array underflow false positives.
+ *
*/
- type = get_type(expr);
- if (!type_unsigned(type))
+ /* Handled in smatch_extra.c */
+ if (get_implied_value(left, &sval) ||
+ get_implied_value(right, &sval))
return;
- /*
- * Assume if (user < trusted) { ... because I am lazy and because this
- * is the correct way to write code.
- */
- if (!get_user_rl(expr->left, &left))
+ get_user_rl(left, &left_rl);
+ get_user_rl(right, &right_rl);
+
+ /* nothing to do */
+ if (!left_rl && !right_rl)
return;
- if (get_user_rl(expr->right, &right))
+ /* if both sides are user data that's not a good limit */
+ if (left_rl && right_rl)
return;
- if (!sval_is_negative(rl_min(left)))
- return;
- min = rl_min(left);
- minus_one.type = rl_type(left);
- minus_one.value = -1;
- non_negative = remove_range(left, min, minus_one);
+ if (left_rl)
+ user_rl = left_rl;
+ else
+ user_rl = right_rl;
+ type = get_type(expr);
+ if (type_unsigned(type))
+ user_rl = strip_negatives(user_rl);
+ capped_state = alloc_estate_rl(user_rl);
+ estate_set_capped(capped_state);
+
switch (expr->op) {
case '<':
case SPECIAL_UNSIGNED_LT:
case SPECIAL_LTE:
case SPECIAL_UNSIGNED_LTE:
- set_true_false_states_expr(my_id, expr->left,
- alloc_estate_rl(non_negative), NULL);
+ if (left_rl)
+ left_true = capped_state;
+ else
+ right_false = capped_state;
break;
case '>':
case SPECIAL_UNSIGNED_GT:
case SPECIAL_GTE:
case SPECIAL_UNSIGNED_GTE:
- set_true_false_states_expr(my_id, expr->left,
- NULL, alloc_estate_rl(non_negative));
+ if (left_rl)
+ left_false = capped_state;
+ else
+ right_true = capped_state;
break;
}
+
+ set_true_false_states_expr(my_id, left, left_true, left_false);
+ set_true_false_states_expr(my_id, right, right_true, right_false);
}
static void match_condition(struct expression *expr)
{
if (expr->type != EXPR_COMPARE)
@@ -604,11 +777,11 @@
expr->op == SPECIAL_NOTEQUAL) {
handle_eq_noteq(expr);
return;
}
- handle_unsigned_lt_gt(expr);
+ handle_compare(expr);
}
static void match_user_assign_function(const char *fn, struct expression *expr, void *unused)
{
tag_as_user_data(expr->left);
@@ -652,42 +825,10 @@
return 1;
}
return 0;
}
-struct db_info {
- struct range_list *rl;
- struct expression *call;
-};
-static int returned_rl_callback(void *_info, int argc, char **argv, char **azColName)
-{
- struct db_info *db_info = _info;
- struct range_list *rl;
- char *return_ranges = argv[0];
- char *user_ranges = argv[1];
- struct expression *arg;
- int comparison;
-
- if (argc != 2)
- return 0;
-
- call_results_to_rl(db_info->call, get_type(db_info->call), user_ranges, &rl);
- if (str_to_comparison_arg(return_ranges, db_info->call, &comparison, &arg) &&
- comparison == SPECIAL_EQUAL) {
- struct range_list *orig_rl;
-
- if (!get_user_rl(arg, &orig_rl))
- return 0;
- rl = rl_intersection(rl, orig_rl);
- if (!rl)
- return 0;
- }
- db_info->rl = rl_union(db_info->rl, rl);
-
- return 0;
-}
-
static int has_user_data(struct symbol *sym)
{
struct sm_state *tmp;
FOR_EACH_MY_SM(my_id, __get_cur_stree(), tmp) {
@@ -713,54 +854,41 @@
return 0;
}
static int db_returned_user_rl(struct expression *call, struct range_list **rl)
{
- struct db_info db_info = {};
+ struct smatch_state *state;
+ char buf[48];
- /* for function pointers assume everything is used */
- if (call->fn->type != EXPR_SYMBOL)
- return 0;
if (is_fake_call(call))
return 0;
-
- db_info.call = call;
- run_sql(&returned_rl_callback, &db_info,
- "select return, value from return_states where %s and type = %d and parameter = -1 and key = '$';",
- get_static_filter(call->fn->symbol), USER_DATA3_SET);
- if (db_info.rl) {
- func_gets_user_data = true;
- *rl = db_info.rl;
- return 1;
- }
-
- run_sql(&returned_rl_callback, &db_info,
- "select return, value from return_states where %s and type = %d and parameter = -1 and key = '$';",
- get_static_filter(call->fn->symbol), USER_DATA3);
- if (db_info.rl) {
- if (!we_pass_user_data(call))
+ snprintf(buf, sizeof(buf), "return %p", call);
+ state = get_state(my_id, buf, NULL);
+ if (!state || !estate_rl(state))
return 0;
- *rl = db_info.rl;
+ *rl = estate_rl(state);
return 1;
- }
-
- return 0;
}
struct stree *get_user_stree(void)
{
return get_all_states_stree(my_id);
}
static int user_data_flag;
static int no_user_data_flag;
-static struct range_list *var_user_rl(struct expression *expr)
+struct range_list *var_user_rl(struct expression *expr)
{
struct smatch_state *state;
struct range_list *rl;
struct range_list *absolute_rl;
+ if (expr->type == EXPR_PREOP && expr->op == '&') {
+ no_user_data_flag = 1;
+ return NULL;
+ }
+
if (expr->type == EXPR_BINOP && expr->op == '%') {
struct range_list *left, *right;
if (!get_user_rl(expr->right, &right))
return NULL;
@@ -767,11 +895,11 @@
get_absolute_rl(expr->left, &left);
rl = rl_binop(left, '%', right);
goto found;
}
- if (!option_spammy && expr->type == EXPR_BINOP && expr->op == '/') {
+ if (expr->type == EXPR_BINOP && expr->op == '/') {
struct range_list *left = NULL;
struct range_list *right = NULL;
struct range_list *abs_right;
/*
@@ -837,37 +965,41 @@
user_data_flag = 1;
absolute_rl = var_to_absolute_rl(expr);
return clone_rl(rl_intersection(rl, absolute_rl));
}
+static bool is_ptr_subtract(struct expression *expr)
+{
+ expr = strip_expr(expr);
+ if (!expr)
+ return false;
+ if (expr->type == EXPR_BINOP && expr->op == '-' &&
+ type_is_ptr(get_type(expr->left))) {
+ return true;
+ }
+ return false;
+}
+
int get_user_rl(struct expression *expr, struct range_list **rl)
{
+ if (is_ptr_subtract(expr))
+ return 0;
+
user_data_flag = 0;
no_user_data_flag = 0;
custom_get_absolute_rl(expr, &var_user_rl, rl);
if (!user_data_flag || no_user_data_flag)
*rl = NULL;
return !!*rl;
}
-int get_user_rl_spammy(struct expression *expr, struct range_list **rl)
-{
- int ret;
-
- option_spammy++;
- ret = get_user_rl(expr, rl);
- option_spammy--;
-
- return ret;
-}
-
int is_user_rl(struct expression *expr)
{
struct range_list *tmp;
- return get_user_rl_spammy(expr, &tmp);
+ return !!get_user_rl(expr, &tmp);
}
int get_user_rl_var_sym(const char *name, struct symbol *sym, struct range_list **rl)
{
struct smatch_state *state;
@@ -878,27 +1010,39 @@
return 1;
}
return 0;
}
-static void match_call_info(struct expression *expr)
+static char *get_user_rl_str(struct expression *expr, struct symbol *type)
{
struct range_list *rl;
+ static char buf[64];
+
+ if (!get_user_rl(expr, &rl))
+ return NULL;
+ rl = cast_rl(type, rl);
+ snprintf(buf, sizeof(buf), "%s%s",
+ show_rl(rl), user_rl_capped(expr) ? "[c]" : "");
+ return buf;
+}
+
+static void match_call_info(struct expression *expr)
+{
struct expression *arg;
struct symbol *type;
- int i = 0;
+ char *str;
+ int i;
i = -1;
FOR_EACH_PTR(expr->args, arg) {
i++;
type = get_arg_type(expr->fn, i);
-
- if (!get_user_rl(arg, &rl))
+ str = get_user_rl_str(arg, type);
+ if (!str)
continue;
- rl = cast_rl(type, rl);
- sql_insert_caller_info(expr, USER_DATA3, i, "$", show_rl(rl));
+ sql_insert_caller_info(expr, USER_DATA, i, "$", str);
} END_FOR_EACH_PTR(arg);
}
static int is_struct_ptr(struct symbol *sym)
{
@@ -918,10 +1062,11 @@
static void struct_member_callback(struct expression *call, int param, char *printed_name, struct sm_state *sm)
{
struct smatch_state *state;
struct range_list *rl;
struct symbol *type;
+ char buf[64];
/*
* Smatch uses a hack where if we get an unsigned long we say it's
* both user data and it points to user data. But if we pass it to a
* function which takes an int, then it's just user data. There's not
@@ -937,45 +1082,106 @@
if (strcmp(printed_name, "*$") == 0 &&
is_struct_ptr(sm->sym))
return;
- state = get_state(SMATCH_EXTRA, sm->name, sm->sym);
+ state = __get_state(SMATCH_EXTRA, sm->name, sm->sym);
if (!state || !estate_rl(state))
rl = estate_rl(sm->state);
else
rl = rl_intersection(estate_rl(sm->state), estate_rl(state));
- sql_insert_caller_info(call, USER_DATA3, param, printed_name, show_rl(rl));
+ if (!rl)
+ return;
+
+ snprintf(buf, sizeof(buf), "%s%s", show_rl(rl),
+ estate_capped(sm->state) ? "[c]" : "");
+ sql_insert_caller_info(call, USER_DATA, param, printed_name, buf);
}
+static void db_param_set(struct expression *expr, int param, char *key, char *value)
+{
+ struct expression *arg;
+ char *name;
+ struct symbol *sym;
+ struct smatch_state *state;
+
+ while (expr->type == EXPR_ASSIGNMENT)
+ expr = strip_expr(expr->right);
+ if (expr->type != EXPR_CALL)
+ return;
+
+ arg = get_argument_from_call_expr(expr->args, param);
+ if (!arg)
+ return;
+ name = get_variable_from_key(arg, key, &sym);
+ if (!name || !sym)
+ goto free;
+
+ state = get_state(my_id, name, sym);
+ if (!state)
+ goto free;
+
+ set_state(my_id, name, sym, alloc_estate_empty());
+free:
+ free_string(name);
+}
+
+static bool param_data_capped(const char *value)
+{
+ if (strstr(value, ",c") || strstr(value, "[c"))
+ return true;
+ return false;
+}
+
static void set_param_user_data(const char *name, struct symbol *sym, char *key, char *value)
{
struct range_list *rl = NULL;
struct smatch_state *state;
+ struct expression *expr;
struct symbol *type;
char fullname[256];
+ char *key_orig = key;
+ bool add_star = false;
- if (strcmp(key, "*$") == 0)
- snprintf(fullname, sizeof(fullname), "*%s", name);
- else if (strncmp(key, "$", 1) == 0)
- snprintf(fullname, 256, "%s%s", name, key + 1);
- else
- return;
+ if (strcmp(key, "**$") == 0) {
+ snprintf(fullname, sizeof(fullname), "**%s", name);
+ } else {
+ if (key[0] == '*') {
+ add_star = true;
+ key++;
+ }
- type = get_member_type_from_key(symbol_expression(sym), key);
+ snprintf(fullname, 256, "%s%s%s", add_star ? "*" : "", name, key + 1);
+ }
- /* if the caller passes a void pointer with user data */
- if (strcmp(key, "*$") == 0 && type && type != &void_ctype) {
- struct expression *expr = symbol_expression(sym);
+ expr = symbol_expression(sym);
+ type = get_member_type_from_key(expr, key_orig);
- tag_as_user_data(expr);
- set_points_to_user_data(expr);
+ /*
+ * Say this function takes a struct ponter but the caller passes
+ * this_function(skb->data). We have two options, we could pass *$
+ * as user data or we could pass foo->bar, foo->baz as user data.
+ * The second option is easier to implement so we do that.
+ *
+ */
+ if (strcmp(key_orig, "*$") == 0) {
+ struct symbol *tmp = type;
+
+ while (tmp && tmp->type == SYM_PTR)
+ tmp = get_real_base_type(tmp);
+
+ if (tmp && (tmp->type == SYM_STRUCT || tmp->type == SYM_UNION)) {
+ tag_as_user_data(symbol_expression(sym));
return;
}
+ }
+
str_to_rl(type, value, &rl);
state = alloc_estate_rl(rl);
+ if (param_data_capped(value) || is_capped(expr))
+ estate_set_capped(state);
set_state(my_id, fullname, sym, state);
}
static void set_called(const char *name, struct symbol *sym, char *key, char *value)
{
@@ -1010,12 +1216,29 @@
FOR_EACH_PTR(sym->ctype.base_type->arguments, arg) {
set_state(my_id, arg->ident->name, arg, alloc_estate_whole(get_real_base_type(arg)));
} END_FOR_EACH_PTR(arg);
}
+static void store_user_data_return(struct expression *expr, char *key, char *value)
+{
+ struct range_list *rl;
+ struct symbol *type;
+ char buf[48];
+
+ if (strcmp(key, "$") != 0)
+ return;
+
+ type = get_type(expr);
+ snprintf(buf, sizeof(buf), "return %p", expr);
+ call_results_to_rl(expr, type, value, &rl);
+
+ set_state(my_id, buf, NULL, alloc_estate_rl(rl));
+}
+
static void set_to_user_data(struct expression *expr, char *key, char *value)
{
+ struct smatch_state *state;
char *name;
struct symbol *sym;
struct symbol *type;
struct range_list *rl = NULL;
@@ -1024,14 +1247,16 @@
if (!name || !sym)
goto free;
call_results_to_rl(expr, type, value, &rl);
- set_state(my_id, name, sym, alloc_estate_rl(rl));
+ state = alloc_estate_rl(rl);
+ if (param_data_capped(value))
+ estate_set_capped(state);
+ set_state(my_id, name, sym, state);
free:
free_string(name);
-
}
static void returns_param_user_data(struct expression *expr, int param, char *key, char *value)
{
struct expression *arg;
@@ -1045,12 +1270,14 @@
if (!we_pass_user_data(call))
return;
if (param == -1) {
- if (expr->type != EXPR_ASSIGNMENT)
+ if (expr->type != EXPR_ASSIGNMENT) {
+ store_user_data_return(expr, key, value);
return;
+ }
set_to_user_data(expr->left, key, value);
return;
}
arg = get_argument_from_call_expr(call->args, param);
@@ -1064,12 +1291,14 @@
struct expression *arg;
func_gets_user_data = true;
if (param == -1) {
- if (expr->type != EXPR_ASSIGNMENT)
+ if (expr->type != EXPR_ASSIGNMENT) {
+ store_user_data_return(expr, key, value);
return;
+ }
if (strcmp(key, "*$") == 0) {
set_points_to_user_data(expr->left);
tag_as_user_data(expr->left);
} else {
set_to_user_data(expr->left, key, value);
@@ -1086,22 +1315,10 @@
if (!arg)
return;
set_to_user_data(arg, key, value);
}
-static int has_empty_state(struct sm_state *sm)
-{
- struct sm_state *tmp;
-
- FOR_EACH_PTR(sm->possible, tmp) {
- if (!estate_rl(tmp->state))
- return 1;
- } END_FOR_EACH_PTR(tmp);
-
- return 0;
-}
-
static void param_set_to_user_data(int return_id, char *return_ranges, struct expression *expr)
{
struct sm_state *sm;
struct smatch_state *start_state;
struct range_list *rl;
@@ -1108,23 +1325,25 @@
int param;
char *return_str;
const char *param_name;
struct symbol *ret_sym;
bool return_found = false;
+ bool pointed_at_found = false;
+ char buf[64];
expr = strip_expr(expr);
return_str = expr_to_str(expr);
ret_sym = expr_to_sym(expr);
FOR_EACH_MY_SM(my_id, __get_cur_stree(), sm) {
- if (has_empty_state(sm))
- continue;
-
param = get_param_num_from_sym(sm->sym);
if (param < 0)
continue;
+ if (!param_was_set_var_sym(sm->name, sm->sym))
+ continue;
+
/* The logic here was that if we were passed in a user data then
* we don't record that. It's like the difference between
* param_filter and param_set. When I think about it, I'm not
* sure it actually works. It's probably harmless because we
* checked earlier that we're not returning a parameter...
@@ -1138,24 +1357,19 @@
if (!param_name)
continue;
if (strcmp(param_name, "$") == 0) /* The -1 param is handled after the loop */
continue;
+ snprintf(buf, sizeof(buf), "%s%s",
+ show_rl(estate_rl(sm->state)),
+ estate_capped(sm->state) ? "[c]" : "");
sql_insert_return_states(return_id, return_ranges,
- func_gets_user_data ? USER_DATA3_SET : USER_DATA3,
- param, param_name, show_rl(estate_rl(sm->state)));
+ func_gets_user_data ? USER_DATA_SET : USER_DATA,
+ param, param_name, buf);
} END_FOR_EACH_SM(sm);
- if (points_to_user_data(expr)) {
- sql_insert_return_states(return_id, return_ranges,
- (is_skb_data(expr) || !func_gets_user_data) ?
- USER_DATA3_SET : USER_DATA3,
- -1, "*$", "");
- goto free_string;
- }
-
-
+ /* This if for "return foo;" where "foo->bar" is user data. */
FOR_EACH_MY_SM(my_id, __get_cur_stree(), sm) {
if (!ret_sym)
break;
if (ret_sym != sm->sym)
continue;
@@ -1163,27 +1377,65 @@
param_name = state_name_to_param_name(sm->name, return_str);
if (!param_name)
continue;
if (strcmp(param_name, "$") == 0)
return_found = true;
+ if (strcmp(param_name, "*$") == 0)
+ pointed_at_found = true;
+ snprintf(buf, sizeof(buf), "%s%s",
+ show_rl(estate_rl(sm->state)),
+ estate_capped(sm->state) ? "[c]" : "");
sql_insert_return_states(return_id, return_ranges,
- func_gets_user_data ? USER_DATA3_SET : USER_DATA3,
- -1, param_name, show_rl(estate_rl(sm->state)));
+ func_gets_user_data ? USER_DATA_SET : USER_DATA,
+ -1, param_name, buf);
} END_FOR_EACH_SM(sm);
-
+ /* This if for "return ntohl(foo);" */
if (!return_found && get_user_rl(expr, &rl)) {
+ snprintf(buf, sizeof(buf), "%s%s",
+ show_rl(rl), user_rl_capped(expr) ? "[c]" : "");
sql_insert_return_states(return_id, return_ranges,
- func_gets_user_data ? USER_DATA3_SET : USER_DATA3,
- -1, "$", show_rl(rl));
- goto free_string;
+ func_gets_user_data ? USER_DATA_SET : USER_DATA,
+ -1, "$", buf);
}
-free_string:
+ /*
+ * This is to handle things like return skb->data where we don't set a
+ * state for that.
+ */
+ if (!pointed_at_found && points_to_user_data(expr)) {
+ sql_insert_return_states(return_id, return_ranges,
+ (is_skb_data(expr) || func_gets_user_data) ?
+ USER_DATA_SET : USER_DATA,
+ -1, "*$", "s64min-s64max");
+ }
+
free_string(return_str);
}
+static void returns_param_capped(struct expression *expr, int param, char *key, char *value)
+{
+ struct smatch_state *state, *new;
+ struct symbol *sym;
+ char *name;
+
+ name = return_state_to_var_sym(expr, param, key, &sym);
+ if (!name || !sym)
+ goto free;
+
+ state = get_state(my_id, name, sym);
+ if (!state || estate_capped(state))
+ goto free;
+
+ new = clone_estate(state);
+ estate_set_capped(new);
+
+ set_state(my_id, name, sym, new);
+free:
+ free_string(name);
+}
+
static struct int_stack *gets_data_stack;
static void match_function_def(struct symbol *sym)
{
func_gets_user_data = false;
}
@@ -1196,19 +1448,21 @@
static void match_inline_end(struct expression *expr)
{
func_gets_user_data = pop_int(&gets_data_stack);
}
-void register_kernel_user_data2(int id)
+void register_kernel_user_data(int id)
{
int i;
my_id = id;
if (option_project != PROJ_KERNEL)
return;
+ set_dynamic_states(my_id);
+
add_hook(&match_function_def, FUNC_DEF_HOOK);
add_hook(&match_inline_start, INLINE_FN_START);
add_hook(&match_inline_end, INLINE_FN_END);
add_hook(&save_start_states, AFTER_DEF_HOOK);
@@ -1236,24 +1490,25 @@
add_function_hook("sscanf", &match_sscanf, NULL);
add_hook(&match_syscall_definition, AFTER_DEF_HOOK);
add_hook(&match_assign, ASSIGNMENT_HOOK);
+ select_return_states_hook(PARAM_SET, &db_param_set);
add_hook(&match_condition, CONDITION_HOOK);
add_hook(&match_call_info, FUNCTION_CALL_HOOK);
add_member_info_callback(my_id, struct_member_callback);
- select_caller_info_hook(set_param_user_data, USER_DATA3);
- select_return_states_hook(USER_DATA3, &returns_param_user_data);
- select_return_states_hook(USER_DATA3_SET, &returns_param_user_data_set);
+ select_caller_info_hook(set_param_user_data, USER_DATA);
+ select_return_states_hook(USER_DATA, &returns_param_user_data);
+ select_return_states_hook(USER_DATA_SET, &returns_param_user_data_set);
+ select_return_states_hook(CAPPED_DATA, &returns_param_capped);
add_split_return_callback(¶m_set_to_user_data);
}
-void register_kernel_user_data3(int id)
+void register_kernel_user_data2(int id)
{
my_call_id = id;
if (option_project != PROJ_KERNEL)
return;
select_caller_info_hook(set_called, INTERNAL);
}
-