logd: liblog: whitelist "snet_event_log"
Dangerous bridge to cross to whitelist, who is special, who is not?
Rationalized as these events are used to catch exploits on platform.
As it stands no one should be allowed to block any messages in the
security context, not even for development purposes.
Bug: 26178938
Change-Id: Ibdc76bc0fe29ba05be168b623af1c9f41d7edbd2
diff --git a/liblog/Android.mk b/liblog/Android.mk
index a183db8..4ab5006 100644
--- a/liblog/Android.mk
+++ b/liblog/Android.mk
@@ -22,7 +22,7 @@
# 's/^\([0-9]*\)[ \t]*liblog[ \t].*/-DLIBLOG_LOG_TAG=\1/p' \
# $(LOCAL_PATH)/event.logtags)
# so make sure we do not regret hard-coding it as follows:
-liblog_cflags := -DLIBLOG_LOG_TAG=1005
+liblog_cflags := -DLIBLOG_LOG_TAG=1005 -DSNET_EVENT_LOG_TAG=1397638484
liblog_host_sources := logd_write.c log_event_write.c fake_log_device.c event.logtags
liblog_target_sources := logd_write.c log_event_write.c event_tag_map.c log_time.cpp log_is_loggable.c
diff --git a/liblog/logd_write.c b/liblog/logd_write.c
index 5406c50..ec86e6b 100644
--- a/liblog/logd_write.c
+++ b/liblog/logd_write.c
@@ -221,50 +221,48 @@
return -EPERM;
}
} else if (log_id == LOG_ID_EVENTS) {
- static atomic_uintptr_t map;
- int ret;
- const char *tag;
- EventTagMap *m, *f;
-
if (vec[0].iov_len < 4) {
return -EINVAL;
}
+ if (((uint32_t *)vec[0].iov_base)[0] != htole32(SNET_EVENT_LOG_TAG)) {
+ static atomic_uintptr_t map;
+ int ret;
+ const char *tag = NULL;
+ EventTagMap *m, *f = NULL;
- tag = NULL;
- f = NULL;
- m = (EventTagMap *)atomic_load(&map);
-
- if (!m) {
- ret = trylock();
- m = (EventTagMap *)atomic_load(&map); /* trylock flush cache */
+ m = (EventTagMap *)atomic_load(&map);
if (!m) {
- m = android_openEventTagMap(EVENT_TAG_MAP_FILE);
- if (ret) { /* trylock failed, use local copy, mark for close */
- f = m;
- } else {
- if (!m) { /* One chance to open map file */
- m = (EventTagMap *)(uintptr_t)-1LL;
+ ret = trylock();
+ m = (EventTagMap *)atomic_load(&map); /* trylock flush cache */
+ if (!m) {
+ m = android_openEventTagMap(EVENT_TAG_MAP_FILE);
+ if (ret) { /* trylock failed, local copy, mark for close */
+ f = m;
+ } else {
+ if (!m) { /* One chance to open map file */
+ m = (EventTagMap *)(uintptr_t)-1LL;
+ }
+ atomic_store(&map, (uintptr_t)m);
}
- atomic_store(&map, (uintptr_t)m);
+ }
+ if (!ret) { /* trylock succeeded, unlock */
+ unlock();
}
}
- if (!ret) { /* trylock succeeded, unlock */
- unlock();
- }
- }
- if (m && (m != (EventTagMap *)(uintptr_t)-1LL)) {
- tag = android_lookupEventTag(
+ if (m && (m != (EventTagMap *)(uintptr_t)-1LL)) {
+ tag = android_lookupEventTag(
m,
htole32(((uint32_t *)vec[0].iov_base)[0]));
- }
- ret = __android_log_is_loggable(ANDROID_LOG_INFO,
- tag,
- ANDROID_LOG_VERBOSE);
- if (f) { /* local copy marked for close */
- android_closeEventTagMap(f);
- }
- if (!ret) {
- return -EPERM;
+ }
+ ret = __android_log_is_loggable(ANDROID_LOG_INFO,
+ tag,
+ ANDROID_LOG_VERBOSE);
+ if (f) { /* local copy marked for close */
+ android_closeEventTagMap(f);
+ }
+ if (!ret) {
+ return -EPERM;
+ }
}
} else {
/* Validate the incoming tag, tag content can not split across iovec */
diff --git a/logd/Android.mk b/logd/Android.mk
index feca8d5..d19c255 100644
--- a/logd/Android.mk
+++ b/logd/Android.mk
@@ -38,7 +38,9 @@
# event_flag := $(call event_logtags,auditd)
# event_flag += $(call event_logtags,logd)
# so make sure we do not regret hard-coding it as follows:
-event_flag := -DAUDITD_LOG_TAG=1003 -DLOGD_LOG_TAG=1004
+event_flag := -DAUDITD_LOG_TAG=1003 \
+ -DLOGD_LOG_TAG=1004 \
+ -DSNET_EVENT_LOG_TAG=1397638484
LOCAL_CFLAGS := -Werror $(event_flag)
diff --git a/logd/LogBuffer.cpp b/logd/LogBuffer.cpp
index ec32393..1b829c6 100644
--- a/logd/LogBuffer.cpp
+++ b/logd/LogBuffer.cpp
@@ -205,16 +205,20 @@
LogBufferElement *elem = new LogBufferElement(log_id, realtime,
uid, pid, tid, msg, len);
- if (log_id != LOG_ID_SECURITY) {
+ if (log_id != LOG_ID_SECURITY) { // whitelist LOG_ID_SECURITY
int prio = ANDROID_LOG_INFO;
- const char *tag = NULL;
+ const char *tag = (const char *)-1;
if (log_id == LOG_ID_EVENTS) {
- tag = android::tagToName(elem->getTag());
+ // whitelist "snet_event_log"
+ if (elem->getTag() != SNET_EVENT_LOG_TAG) {
+ tag = android::tagToName(elem->getTag());
+ }
} else {
prio = *msg;
tag = msg + 1;
}
- if (!__android_log_is_loggable(prio, tag, ANDROID_LOG_VERBOSE)) {
+ if ((tag != (const char *)-1) &&
+ !__android_log_is_loggable(prio, tag, ANDROID_LOG_VERBOSE)) {
// Log traffic received to total
pthread_mutex_lock(&mLogElementsLock);
stats.add(elem);