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-rwxr-xr-x[-rw-r--r--]init/property_service.c245
1 files changed, 137 insertions, 108 deletions
diff --git a/init/property_service.c b/init/property_service.c
index 059db97..86e35f1 100644..100755
--- a/init/property_service.c
+++ b/init/property_service.c
@@ -40,6 +40,9 @@
#include <sys/atomics.h>
#include <private/android_filesystem_config.h>
+#include <selinux/selinux.h>
+#include <selinux/label.h>
+
#include "property_service.h"
#include "init.h"
#include "util.h"
@@ -76,8 +79,10 @@ struct {
{ "sys.", AID_SYSTEM, 0 },
{ "service.", AID_SYSTEM, 0 },
{ "wlan.", AID_SYSTEM, 0 },
+ { "bluetooth.", AID_BLUETOOTH, 0 },
{ "dhcp.", AID_SYSTEM, 0 },
{ "dhcp.", AID_DHCP, 0 },
+ { "debug.", AID_SYSTEM, 0 },
{ "debug.", AID_SHELL, 0 },
{ "log.", AID_SHELL, 0 },
{ "service.adb.root", AID_SHELL, 0 },
@@ -85,6 +90,8 @@ struct {
{ "persist.sys.", AID_SYSTEM, 0 },
{ "persist.service.", AID_SYSTEM, 0 },
{ "persist.security.", AID_SYSTEM, 0 },
+ { "persist.service.bdroid.", AID_BLUETOOTH, 0 },
+ { "selinux." , AID_SYSTEM, 0 },
{ NULL, 0, 0 }
};
@@ -116,7 +123,7 @@ static int init_workspace(workspace *w, size_t size)
/* dev is a tmpfs that we can use to carve a shared workspace
* out of, so let's do that...
*/
- fd = open("/dev/__properties__", O_RDWR | O_CREAT, 0600);
+ fd = open("/dev/__properties__", O_RDWR | O_CREAT | O_NOFOLLOW, 0600);
if (fd < 0)
return -1;
@@ -129,7 +136,7 @@ static int init_workspace(workspace *w, size_t size)
close(fd);
- fd = open("/dev/__properties__", O_RDONLY);
+ fd = open("/dev/__properties__", O_RDONLY | O_NOFOLLOW);
if (fd < 0)
return -1;
@@ -145,23 +152,11 @@ out:
return -1;
}
-/* (8 header words + 247 toc words) = 1020 bytes */
-/* 1024 bytes header and toc + 247 prop_infos @ 128 bytes = 32640 bytes */
-
-#define PA_COUNT_MAX 247
-#define PA_INFO_START 1024
-#define PA_SIZE 32768
-
static workspace pa_workspace;
-static prop_info *pa_info_array;
-
-extern prop_area *__system_property_area__;
static int init_property_area(void)
{
- prop_area *pa;
-
- if(pa_info_array)
+ if (property_area_inited)
return -1;
if(init_workspace(&pa_workspace, PA_SIZE))
@@ -169,25 +164,54 @@ static int init_property_area(void)
fcntl(pa_workspace.fd, F_SETFD, FD_CLOEXEC);
- pa_info_array = (void*) (((char*) pa_workspace.data) + PA_INFO_START);
+ __system_property_area_init(pa_workspace.data);
- pa = pa_workspace.data;
- memset(pa, 0, PA_SIZE);
- pa->magic = PROP_AREA_MAGIC;
- pa->version = PROP_AREA_VERSION;
-
- /* plug into the lib property services */
- __system_property_area__ = pa;
property_area_inited = 1;
return 0;
}
-static void update_prop_info(prop_info *pi, const char *value, unsigned len)
+static int check_mac_perms(const char *name, char *sctx)
{
- pi->serial = pi->serial | 1;
- memcpy(pi->value, value, len + 1);
- pi->serial = (len << 24) | ((pi->serial + 1) & 0xffffff);
- __futex_wake(&pi->serial, INT32_MAX);
+ if (is_selinux_enabled() <= 0)
+ return 1;
+
+ char *tctx = NULL;
+ const char *class = "property_service";
+ const char *perm = "set";
+ int result = 0;
+
+ if (!sctx)
+ goto err;
+
+ if (!sehandle_prop)
+ goto err;
+
+ if (selabel_lookup(sehandle_prop, &tctx, name, 1) != 0)
+ goto err;
+
+ if (selinux_check_access(sctx, tctx, class, perm, name) == 0)
+ result = 1;
+
+ freecon(tctx);
+ err:
+ return result;
+}
+
+static int check_control_mac_perms(const char *name, char *sctx)
+{
+ /*
+ * Create a name prefix out of ctl.<service name>
+ * The new prefix allows the use of the existing
+ * property service backend labeling while avoiding
+ * mislabels based on true property prefixes.
+ */
+ char ctl_name[PROP_VALUE_MAX+4];
+ int ret = snprintf(ctl_name, sizeof(ctl_name), "ctl.%s", name);
+
+ if (ret < 0 || (size_t) ret >= sizeof(ctl_name))
+ return 0;
+
+ return check_mac_perms(ctl_name, sctx);
}
/*
@@ -196,17 +220,18 @@ static void update_prop_info(prop_info *pi, const char *value, unsigned len)
*
* Returns 1 if uid allowed, 0 otherwise.
*/
-static int check_control_perms(const char *name, unsigned int uid, unsigned int gid) {
+static int check_control_perms(const char *name, unsigned int uid, unsigned int gid, char *sctx) {
+
int i;
if (uid == AID_SYSTEM || uid == AID_ROOT)
- return 1;
+ return check_control_mac_perms(name, sctx);
/* Search the ACL */
for (i = 0; control_perms[i].service; i++) {
if (strcmp(control_perms[i].service, name) == 0) {
if ((uid && control_perms[i].uid == uid) ||
(gid && control_perms[i].gid == gid)) {
- return 1;
+ return check_control_mac_perms(name, sctx);
}
}
}
@@ -217,22 +242,22 @@ static int check_control_perms(const char *name, unsigned int uid, unsigned int
* Checks permissions for setting system properties.
* Returns 1 if uid allowed, 0 otherwise.
*/
-static int check_perms(const char *name, unsigned int uid, unsigned int gid)
+static int check_perms(const char *name, unsigned int uid, unsigned int gid, char *sctx)
{
int i;
- if (uid == 0)
- return 1;
-
if(!strncmp(name, "ro.", 3))
name +=3;
+ if (uid == 0)
+ return check_mac_perms(name, sctx);
+
for (i = 0; property_perms[i].prefix; i++) {
- int tmp;
if (strncmp(property_perms[i].prefix, name,
strlen(property_perms[i].prefix)) == 0) {
if ((uid && property_perms[i].uid == uid) ||
(gid && property_perms[i].gid == gid)) {
- return 1;
+
+ return check_mac_perms(name, sctx);
}
}
}
@@ -240,30 +265,19 @@ static int check_perms(const char *name, unsigned int uid, unsigned int gid)
return 0;
}
-const char* property_get(const char *name)
+int __property_get(const char *name, char *value)
{
- prop_info *pi;
-
- if(strlen(name) >= PROP_NAME_MAX) return 0;
-
- pi = (prop_info*) __system_property_find(name);
-
- if(pi != 0) {
- return pi->value;
- } else {
- return 0;
- }
+ return __system_property_get(name, value);
}
static void write_persistent_property(const char *name, const char *value)
{
- const char *tempPath = PERSISTENT_PROPERTY_DIR "/.temp";
+ char tempPath[PATH_MAX];
char path[PATH_MAX];
- int fd, length;
-
- snprintf(path, sizeof(path), "%s/%s", PERSISTENT_PROPERTY_DIR, name);
+ int fd;
- fd = open(tempPath, O_WRONLY|O_CREAT|O_TRUNC, 0600);
+ snprintf(tempPath, sizeof(tempPath), "%s/.temp.XXXXXX", PERSISTENT_PROPERTY_DIR);
+ fd = mkstemp(tempPath);
if (fd < 0) {
ERROR("Unable to write persistent property to temp file %s errno: %d\n", tempPath, errno);
return;
@@ -271,6 +285,7 @@ static void write_persistent_property(const char *name, const char *value)
write(fd, value, strlen(value));
close(fd);
+ snprintf(path, sizeof(path), "%s/%s", PERSISTENT_PROPERTY_DIR, name);
if (rename(tempPath, path)) {
unlink(tempPath);
ERROR("Unable to rename persistent property file %s to %s\n", tempPath, path);
@@ -279,11 +294,11 @@ static void write_persistent_property(const char *name, const char *value)
int property_set(const char *name, const char *value)
{
- prop_area *pa;
prop_info *pi;
+ int ret;
- int namelen = strlen(name);
- int valuelen = strlen(value);
+ size_t namelen = strlen(name);
+ size_t valuelen = strlen(value);
if(namelen >= PROP_NAME_MAX) return -1;
if(valuelen >= PROP_VALUE_MAX) return -1;
@@ -295,25 +310,13 @@ int property_set(const char *name, const char *value)
/* ro.* properties may NEVER be modified once set */
if(!strncmp(name, "ro.", 3)) return -1;
- pa = __system_property_area__;
- update_prop_info(pi, value, valuelen);
- pa->serial++;
- __futex_wake(&pa->serial, INT32_MAX);
+ __system_property_update(pi, value, valuelen);
} else {
- pa = __system_property_area__;
- if(pa->count == PA_COUNT_MAX) return -1;
-
- pi = pa_info_array + pa->count;
- pi->serial = (valuelen << 24);
- memcpy(pi->name, name, namelen + 1);
- memcpy(pi->value, value, valuelen + 1);
-
- pa->toc[pa->count] =
- (namelen << 24) | (((unsigned) pi) - ((unsigned) pa));
-
- pa->count++;
- pa->serial++;
- __futex_wake(&pa->serial, INT32_MAX);
+ ret = __system_property_add(name, namelen, value, valuelen);
+ if (ret < 0) {
+ ERROR("Failed to set '%s'='%s'", name, value);
+ return ret;
+ }
}
/* If name starts with "net." treat as a DNS property. */
if (strncmp("net.", name, strlen("net.")) == 0) {
@@ -333,26 +336,14 @@ int property_set(const char *name, const char *value)
* to prevent them from being overwritten by default values.
*/
write_persistent_property(name, value);
+ } else if (strcmp("selinux.reload_policy", name) == 0 &&
+ strcmp("1", value) == 0) {
+ selinux_reload_policy();
}
property_changed(name, value);
return 0;
}
-static int property_list(void (*propfn)(const char *key, const char *value, void *cookie),
- void *cookie)
-{
- char name[PROP_NAME_MAX];
- char value[PROP_VALUE_MAX];
- const prop_info *pi;
- unsigned n;
-
- for(n = 0; (pi = __system_property_find_nth(n)); n++) {
- __system_property_read(pi, name, value);
- propfn(name, value, cookie);
- }
- return 0;
-}
-
void handle_property_set_fd()
{
prop_msg msg;
@@ -363,6 +354,7 @@ void handle_property_set_fd()
struct sockaddr_un addr;
socklen_t addr_size = sizeof(addr);
socklen_t cr_size = sizeof(cr);
+ char * source_ctx = NULL;
if ((s = accept(property_set_fd, (struct sockaddr *) &addr, &addr_size)) < 0) {
return;
@@ -371,13 +363,13 @@ void handle_property_set_fd()
/* Check socket options here */
if (getsockopt(s, SOL_SOCKET, SO_PEERCRED, &cr, &cr_size) < 0) {
close(s);
- ERROR("Unable to recieve socket options\n");
+ ERROR("Unable to receive socket options\n");
return;
}
r = TEMP_FAILURE_RETRY(recv(s, &msg, sizeof(msg), 0));
if(r != sizeof(prop_msg)) {
- ERROR("sys_prop: mis-match msg size recieved: %d expected: %d errno: %d\n",
+ ERROR("sys_prop: mis-match msg size received: %d expected: %d errno: %d\n",
r, sizeof(prop_msg), errno);
close(s);
return;
@@ -388,18 +380,20 @@ void handle_property_set_fd()
msg.name[PROP_NAME_MAX-1] = 0;
msg.value[PROP_VALUE_MAX-1] = 0;
+ getpeercon(s, &source_ctx);
+
if(memcmp(msg.name,"ctl.",4) == 0) {
// Keep the old close-socket-early behavior when handling
// ctl.* properties.
close(s);
- if (check_control_perms(msg.value, cr.uid, cr.gid)) {
+ if (check_control_perms(msg.value, cr.uid, cr.gid, source_ctx)) {
handle_control_message((char*) msg.name + 4, (char*) msg.value);
} else {
ERROR("sys_prop: Unable to %s service ctl [%s] uid:%d gid:%d pid:%d\n",
msg.name + 4, msg.value, cr.uid, cr.gid, cr.pid);
}
} else {
- if (check_perms(msg.name, cr.uid, cr.gid)) {
+ if (check_perms(msg.name, cr.uid, cr.gid, source_ctx)) {
property_set((char*) msg.name, (char*) msg.value);
} else {
ERROR("sys_prop: permission denied uid:%d name:%s\n",
@@ -411,6 +405,7 @@ void handle_property_set_fd()
// the property is written to memory.
close(s);
}
+ freecon(source_ctx);
break;
default:
@@ -468,12 +463,14 @@ static void load_properties_from_file(const char *fn)
static void load_persistent_properties()
{
DIR* dir = opendir(PERSISTENT_PROPERTY_DIR);
+ int dir_fd;
struct dirent* entry;
- char path[PATH_MAX];
char value[PROP_VALUE_MAX];
int fd, length;
+ struct stat sb;
if (dir) {
+ dir_fd = dirfd(dir);
while ((entry = readdir(dir)) != NULL) {
if (strncmp("persist.", entry->d_name, strlen("persist.")))
continue;
@@ -482,20 +479,39 @@ static void load_persistent_properties()
continue;
#endif
/* open the file and read the property value */
- snprintf(path, sizeof(path), "%s/%s", PERSISTENT_PROPERTY_DIR, entry->d_name);
- fd = open(path, O_RDONLY);
- if (fd >= 0) {
- length = read(fd, value, sizeof(value) - 1);
- if (length >= 0) {
- value[length] = 0;
- property_set(entry->d_name, value);
- } else {
- ERROR("Unable to read persistent property file %s errno: %d\n", path, errno);
- }
+ fd = openat(dir_fd, entry->d_name, O_RDONLY | O_NOFOLLOW);
+ if (fd < 0) {
+ ERROR("Unable to open persistent property file \"%s\" errno: %d\n",
+ entry->d_name, errno);
+ continue;
+ }
+ if (fstat(fd, &sb) < 0) {
+ ERROR("fstat on property file \"%s\" failed errno: %d\n", entry->d_name, errno);
+ close(fd);
+ continue;
+ }
+
+ // File must not be accessible to others, be owned by root/root, and
+ // not be a hard link to any other file.
+ if (((sb.st_mode & (S_IRWXG | S_IRWXO)) != 0)
+ || (sb.st_uid != 0)
+ || (sb.st_gid != 0)
+ || (sb.st_nlink != 1)) {
+ ERROR("skipping insecure property file %s (uid=%lu gid=%lu nlink=%d mode=%o)\n",
+ entry->d_name, sb.st_uid, sb.st_gid, sb.st_nlink, sb.st_mode);
close(fd);
+ continue;
+ }
+
+ length = read(fd, value, sizeof(value) - 1);
+ if (length >= 0) {
+ value[length] = 0;
+ property_set(entry->d_name, value);
} else {
- ERROR("Unable to open persistent property file %s errno: %d\n", path, errno);
+ ERROR("Unable to read persistent property file %s errno: %d\n",
+ entry->d_name, errno);
}
+ close(fd);
}
closedir(dir);
} else {
@@ -520,6 +536,19 @@ int properties_inited(void)
return property_area_inited;
}
+static void load_override_properties() {
+#ifdef ALLOW_LOCAL_PROP_OVERRIDE
+ char debuggable[PROP_VALUE_MAX];
+ int ret;
+
+ ret = property_get("ro.debuggable", debuggable);
+ if (ret && (strcmp(debuggable, "1") == 0)) {
+ load_properties_from_file(PROP_PATH_LOCAL_OVERRIDE);
+ }
+#endif /* ALLOW_LOCAL_PROP_OVERRIDE */
+}
+
+
/* When booting an encrypted system, /data is not mounted when the
* property service is started, so any properties stored there are
* not loaded. Vold triggers init to load these properties once it
@@ -527,7 +556,7 @@ int properties_inited(void)
*/
void load_persist_props(void)
{
- load_properties_from_file(PROP_PATH_LOCAL_OVERRIDE);
+ load_override_properties();
/* Read persistent properties after all default values have been loaded. */
load_persistent_properties();
}
@@ -538,7 +567,7 @@ void start_property_service(void)
load_properties_from_file(PROP_PATH_SYSTEM_BUILD);
load_properties_from_file(PROP_PATH_SYSTEM_DEFAULT);
- load_properties_from_file(PROP_PATH_LOCAL_OVERRIDE);
+ load_override_properties();
/* Read persistent properties after all default values have been loaded. */
load_persistent_properties();
generated by cgit v1.1 at 2025-10-26 12:50:44 +0000