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authorLennart Poettering <lennart@poettering.net>2013-03-22 00:42:53 +0100
committerLennart Poettering <lennart@poettering.net>2013-03-22 00:42:53 +0100
commitac89bf1d53268d39025a2a00c2effdb3fa447ead (patch)
tree8a1ed549ab3b4938d3d2c296cd66b5c57fd4fc03 /src
parentb8beb2781682738f3a59aab993bf2869447a77c9 (diff)
bus: properly validate object path values
Diffstat (limited to 'src')
-rw-r--r--src/libsystemd-bus/bus-internal.c40
-rw-r--r--src/libsystemd-bus/bus-internal.h6
-rw-r--r--src/libsystemd-bus/bus-message.c65
3 files changed, 91 insertions, 20 deletions
diff --git a/src/libsystemd-bus/bus-internal.c b/src/libsystemd-bus/bus-internal.c
index 19398af6cb..e58a8b1da1 100644
--- a/src/libsystemd-bus/bus-internal.c
+++ b/src/libsystemd-bus/bus-internal.c
@@ -20,3 +20,43 @@
***/
#include "bus-internal.h"
+
+bool object_path_is_valid(const char *p) {
+ const char *q;
+ bool slash;
+
+ if (!p)
+ return false;
+
+ if (p[0] != '/')
+ return false;
+
+ if (p[1] == 0)
+ return true;
+
+ for (slash = true, q = p+1; *q; q++)
+ if (*q == '/') {
+ if (slash)
+ return false;
+
+ slash = true;
+ } else {
+ bool good;
+
+ good =
+ (*q >= 'a' && *q <= 'z') ||
+ (*q >= 'A' && *q <= 'Z') ||
+ (*q >= '0' && *q <= '9') ||
+ *q == '_';
+
+ if (!good)
+ return false;
+
+ slash = false;
+ }
+
+ if (slash)
+ return false;
+
+ return true;
+}
diff --git a/src/libsystemd-bus/bus-internal.h b/src/libsystemd-bus/bus-internal.h
index 636e998c30..809ad823fc 100644
--- a/src/libsystemd-bus/bus-internal.h
+++ b/src/libsystemd-bus/bus-internal.h
@@ -117,3 +117,9 @@ static inline void bus_unrefp(sd_bus **b) {
#define BUS_MESSAGE_SIZE_MAX (64*1024*1024)
#define BUS_AUTH_SIZE_MAX (64*1024)
+
+/* Defined by the specification as maximum size of an array in
+ * bytes */
+#define BUS_ARRAY_MAX_SIZE 67108864
+
+bool object_path_is_valid(const char *p);
diff --git a/src/libsystemd-bus/bus-message.c b/src/libsystemd-bus/bus-message.c
index 524f17eb9f..f5b60f2728 100644
--- a/src/libsystemd-bus/bus-message.c
+++ b/src/libsystemd-bus/bus-message.c
@@ -1374,8 +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))
@@ -1385,6 +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;
@@ -1393,12 +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 */
@@ -1408,6 +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;
@@ -1447,8 +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;
@@ -1565,7 +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);
@@ -2104,6 +2123,7 @@ static int message_peek_fields(
static int message_peek_field_string(
sd_bus_message *m,
+ char type,
size_t *ri,
const char **ret) {
@@ -2123,8 +2143,13 @@ static int message_peek_field_string(
if (r < 0)
return r;
- 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;
+ }
if (ret)
*ret = q;
@@ -2214,7 +2239,7 @@ static int message_skip_fields(
if (t == SD_BUS_TYPE_STRING ||
t == SD_BUS_TYPE_OBJECT_PATH) {
- r = message_peek_field_string(m, ri, NULL);
+ r = message_peek_field_string(m, t, ri, NULL);
if (r < 0)
return r;
@@ -2264,7 +2289,7 @@ 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);
@@ -2341,42 +2366,42 @@ 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, 'o', &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, 's', &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, 's', &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, 's', &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, 's', &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, 's', &ri, &m->sender);
break;