logd: validate and fill in socket credentials
- android::pidToUid() additional checking. Make sure if we have to
convert a PID to an UID that the parse of /proc/<pid>/status
requires a trailing space after the number
- android::tidToPid() added, in the same vein as android::pidToUid().
- stats.tidToPid() added
- If no credentials, set PID to 0 and UID to DEFAULT_OVERFLOWUID
- If credentialed PID is 0, use stats.tidToPid()
- If credentialed UID is DEFAULT_OVERFLOWUID, use stats.pidToUid()
Test: remove +passcred from logd.rc for daemon and confirm very few
UID=65534 or PID=0 cases actually show up
Bug: 37985222
Change-Id: I7d20506e70e67beb3043d1537cf9450ab58dc278
diff --git a/logd/LogStatistics.cpp b/logd/LogStatistics.cpp
index d20d90e..af59ddc 100644
--- a/logd/LogStatistics.cpp
+++ b/logd/LogStatistics.cpp
@@ -14,6 +14,7 @@
* limitations under the License.
*/
+#include <ctype.h>
#include <fcntl.h>
#include <inttypes.h>
#include <pwd.h>
@@ -824,8 +825,10 @@
FILE* fp = fopen(buffer, "r");
if (fp) {
while (fgets(buffer, sizeof(buffer), fp)) {
- int uid;
- if (sscanf(buffer, "Uid: %d", &uid) == 1) {
+ int uid = AID_LOGD;
+ char space = 0;
+ if ((sscanf(buffer, "Uid: %d%c", &uid, &space) == 2) &&
+ isspace(space)) {
fclose(fp);
return uid;
}
@@ -834,12 +837,35 @@
}
return AID_LOGD; // associate this with the logger
}
+
+pid_t tidToPid(pid_t tid) {
+ char buffer[512];
+ snprintf(buffer, sizeof(buffer), "/proc/%u/status", tid);
+ FILE* fp = fopen(buffer, "r");
+ if (fp) {
+ while (fgets(buffer, sizeof(buffer), fp)) {
+ int pid = tid;
+ char space = 0;
+ if ((sscanf(buffer, "Tgid: %d%c", &pid, &space) == 2) &&
+ isspace(space)) {
+ fclose(fp);
+ return pid;
+ }
+ }
+ fclose(fp);
+ }
+ return tid;
+}
}
uid_t LogStatistics::pidToUid(pid_t pid) {
return pidTable.add(pid)->second.getUid();
}
+pid_t LogStatistics::tidToPid(pid_t tid) {
+ return tidTable.add(tid)->second.getPid();
+}
+
// caller must free character string
const char* LogStatistics::pidToName(pid_t pid) const {
// An inconvenient truth ... getName() can alter the object