bus: validate the entire header more closely

[elogind.git] / src / libsystemd-bus / bus-message.c

diff --git a/src/libsystemd-bus/bus-message.c b/src/libsystemd-bus/bus-message.c
index c385ef5ed05b1e39387e6e447677a827c6b2a25c..a22962559de8ed94c298443981c938e70da536ed 100644 (file)
--- a/src/libsystemd-bus/bus-message.c
+++ b/src/libsystemd-bus/bus-message.c
@@ -403,6 +403,8 @@ static int message_new_reply(
 
         if (!call)
                 return -EINVAL;
+        if (!call->sealed)
+                return -EPERM;
         if (call->header->type != SD_BUS_MESSAGE_TYPE_METHOD_CALL)
                 return -EINVAL;
         if (!m)
@@ -766,11 +768,27 @@ int message_append_basic(sd_bus_message *m, char type, const void *p, const void
 
         case SD_BUS_TYPE_STRING:
         case SD_BUS_TYPE_OBJECT_PATH:
+
+                if (!p) {
+                        if (e)
+                                c->signature[c->index] = 0;
+
+                        return -EINVAL;
+                }
+
                 align = 4;
                 sz = 4 + strlen(p) + 1;
                 break;
 
         case SD_BUS_TYPE_SIGNATURE:
+
+                if (!p) {
+                        if (e)
+                                c->signature[c->index] = 0;
+
+                        return -EINVAL;
+                }
+
                 align = 1;
                 sz = 1 + strlen(p) + 1;
                 break;
@@ -1356,8 +1374,7 @@ static int message_peek_body(sd_bus_message *m, size_t *rindex, size_t align, si
         return buffer_peek(m->body, BUS_MESSAGE_BODY_SIZE(m), rindex, align, nbytes, ret);
 }
 
-static bool validate_string(const char *s, size_t l) {
-        assert(s);
+static bool validate_nul(const char *s, size_t l) {
 
         /* Check for NUL chars in the string */
         if (memchr(s, 0, l))
@@ -1367,6 +1384,14 @@ static bool validate_string(const char *s, size_t l) {
         if (s[l] != 0)
                 return false;
 
+        return true;
+}
+
+static bool validate_string(const char *s, size_t l) {
+
+        if (!validate_nul(s, l))
+                return false;
+
         /* Check if valid UTF8 */
         if (!utf8_is_valid(s))
                 return false;
@@ -1375,12 +1400,8 @@ static bool validate_string(const char *s, size_t l) {
 }
 
 static bool validate_signature(const char *s, size_t l) {
-        /* Check for NUL chars in the signature */
-        if (memchr(s, 0, l))
-                return false;
 
-        /* Check for NUL termination */
-        if (s[l] != 0)
+        if (!validate_nul(s, l))
                 return false;
 
         /* Check if valid signature */
@@ -1390,6 +1411,17 @@ static bool validate_signature(const char *s, size_t l) {
         return true;
 }
 
+static bool validate_object_path(const char *s, size_t l) {
+
+        if (!validate_nul(s, l))
+                return false;
+
+        if (!object_path_is_valid(s))
+                return false;
+
+        return true;
+}
+
 int sd_bus_message_read_basic(sd_bus_message *m, char type, void *p) {
         struct bus_container *c;
         int r;
@@ -1429,8 +1461,13 @@ int sd_bus_message_read_basic(sd_bus_message *m, char type, void *p) {
                 if (r == 0)
                         return -EBADMSG;
 
-                if (!validate_string(q, l))
-                        return -EBADMSG;
+                if (type == SD_BUS_TYPE_OBJECT_PATH) {
+                        if (!validate_object_path(q, l))
+                                return -EBADMSG;
+                } else {
+                        if (!validate_string(q, l))
+                                return -EBADMSG;
+                }
 
                 m->rindex = rindex;
                 *(const char**) p = q;
@@ -1547,7 +1584,7 @@ static int bus_message_enter_array(
         if (r <= 0)
                 return r;
 
-        if (BUS_MESSAGE_BSWAP32(m, *(uint32_t*) q) > 67108864)
+        if (BUS_MESSAGE_BSWAP32(m, *(uint32_t*) q) > BUS_ARRAY_MAX_SIZE)
                 return -EBADMSG;
 
         r = message_peek_body(m, &rindex, alignment, 0, NULL);
@@ -2086,6 +2123,7 @@ static int message_peek_fields(
 
 static int message_peek_field_string(
                 sd_bus_message *m,
+                bool (*validate)(const char *p),
                 size_t *ri,
                 const char **ret) {
 
@@ -2105,8 +2143,16 @@ static int message_peek_field_string(
         if (r < 0)
                 return r;
 
-        if (!validate_string(q, l))
-                return -EBADMSG;
+        if (validate) {
+                if (!validate_nul(q, l))
+                        return -EBADMSG;
+
+                if (!validate(q))
+                        return -EBADMSG;
+        } else {
+                if (!validate_string(q, l))
+                        return -EBADMSG;
+        }
 
         if (ret)
                 *ret = q;
@@ -2193,10 +2239,17 @@ static int message_skip_fields(
                 if (!t)
                         return 0;
 
-                if (t == SD_BUS_TYPE_STRING ||
-                    t == SD_BUS_TYPE_OBJECT_PATH) {
+                if (t == SD_BUS_TYPE_STRING) {
 
-                        r = message_peek_field_string(m, ri, NULL);
+                        r = message_peek_field_string(m, NULL, ri, NULL);
+                        if (r < 0)
+                                return r;
+
+                        (*signature)++;
+
+                } else if (t == SD_BUS_TYPE_OBJECT_PATH) {
+
+                        r = message_peek_field_string(m, object_path_is_valid, ri, NULL);
                         if (r < 0)
                                 return r;
 
@@ -2213,8 +2266,8 @@ static int message_skip_fields(
                 } else if (bus_type_is_basic(t)) {
                         size_t align, k;
 
-                        align = bus_type_get_alignment(align);
-                        k = bus_type_get_size(align);
+                        align = bus_type_get_alignment(t);
+                        k = bus_type_get_size(t);
 
                         r = message_peek_fields(m, ri, align, k, NULL);
                         if (r < 0)
@@ -2246,7 +2299,7 @@ static int message_skip_fields(
                                         return r;
 
                                 nas = BUS_MESSAGE_BSWAP32(m, *(uint32_t*) q);
-                                if (nas > 67108864)
+                                if (nas > BUS_ARRAY_MAX_SIZE)
                                         return -EBADMSG;
 
                                 r = message_peek_fields(m, ri, alignment, 0, NULL);
@@ -2323,42 +2376,42 @@ static int message_parse_fields(sd_bus_message *m) {
                         if (!streq(signature, "o"))
                                 return -EBADMSG;
 
-                        r = message_peek_field_string(m, &ri, &m->path);
+                        r = message_peek_field_string(m, object_path_is_valid, &ri, &m->path);
                         break;
 
                 case SD_BUS_MESSAGE_HEADER_INTERFACE:
                         if (!streq(signature, "s"))
                                 return -EBADMSG;
 
-                        r = message_peek_field_string(m, &ri, &m->interface);
+                        r = message_peek_field_string(m, interface_name_is_valid, &ri, &m->interface);
                         break;
 
                 case SD_BUS_MESSAGE_HEADER_MEMBER:
                         if (!streq(signature, "s"))
                                 return -EBADMSG;
 
-                        r = message_peek_field_string(m, &ri, &m->member);
+                        r = message_peek_field_string(m, member_name_is_valid, &ri, &m->member);
                         break;
 
                 case SD_BUS_MESSAGE_HEADER_ERROR_NAME:
                         if (!streq(signature, "s"))
                                 return -EBADMSG;
 
-                        r = message_peek_field_string(m, &ri, &m->error.name);
+                        r = message_peek_field_string(m, error_name_is_valid, &ri, &m->error.name);
                         break;
 
                 case SD_BUS_MESSAGE_HEADER_DESTINATION:
                         if (!streq(signature, "s"))
                                 return -EBADMSG;
 
-                        r = message_peek_field_string(m, &ri, &m->destination);
+                        r = message_peek_field_string(m, service_name_is_valid, &ri, &m->destination);
                         break;
 
                 case SD_BUS_MESSAGE_HEADER_SENDER:
                         if (!streq(signature, "s"))
                                 return -EBADMSG;
 
-                        r = message_peek_field_string(m, &ri, &m->sender);
+                        r = message_peek_field_string(m, service_name_is_valid, &ri, &m->sender);
                         break;
 
 
@@ -2389,6 +2442,12 @@ static int message_parse_fields(sd_bus_message *m) {
                                 return -EBADMSG;
 
                         r = message_peek_field_uint32(m, &ri, &m->reply_serial);
+                        if (r < 0)
+                                return r;
+
+                        if (m->reply_serial == 0)
+                                return -EBADMSG;
+
                         break;
 
                 default:
@@ -2441,14 +2500,17 @@ static void setup_iovec(sd_bus_message *m) {
         assert(m->sealed);
 
         m->n_iovec = 0;
+        m->size = 0;
 
         m->iovec[m->n_iovec].iov_base = m->header;
         m->iovec[m->n_iovec].iov_len = sizeof(*m->header);
+        m->size += m->iovec[m->n_iovec].iov_len;
         m->n_iovec++;
 
         if (m->fields) {
                 m->iovec[m->n_iovec].iov_base = m->fields;
                 m->iovec[m->n_iovec].iov_len = m->header->fields_size;
+                m->size += m->iovec[m->n_iovec].iov_len;
                 m->n_iovec++;
 
                 if (m->header->fields_size % 8 != 0) {
@@ -2456,6 +2518,7 @@ static void setup_iovec(sd_bus_message *m) {
 
                         m->iovec[m->n_iovec].iov_base = (void*) padding;
                         m->iovec[m->n_iovec].iov_len = 8 - m->header->fields_size % 8;
+                        m->size += m->iovec[m->n_iovec].iov_len;
                         m->n_iovec++;
                 }
         }
@@ -2463,6 +2526,7 @@ static void setup_iovec(sd_bus_message *m) {
         if (m->body) {
                 m->iovec[m->n_iovec].iov_base = m->body;
                 m->iovec[m->n_iovec].iov_len = m->header->body_size;
+                m->size += m->iovec[m->n_iovec].iov_len;
                 m->n_iovec++;
         }
 }