When dropping privileges, check return values.

setuid() and family can fail.  Check return values to make
sure this doesn't happen unexpectedly.

Also call setgid() to drop root group permissions.

Change-Id: Id06fbe6239e2ed2fe23368695e333514e0581e6d

1 files changed, 12 insertions, 2 deletions

diff --git a/cmds/dumpstate/dumpstate.c b/cmds/dumpstate/dumpstate.c
index 082e704..6e9caaf 100644
--- a/cmds/dumpstate/dumpstate.c
+++ b/cmds/dumpstate/dumpstate.c
@@ -218,8 +218,18 @@ int main(int argc, char *argv[]) {
 
     /* switch to non-root user and group */
     gid_t groups[] = { AID_LOG, AID_SDCARD_RW, AID_MOUNT };
-    setgroups(sizeof(groups)/sizeof(groups[0]), groups);
-    setuid(AID_SHELL);
+    if (setgroups(sizeof(groups)/sizeof(groups[0]), groups) != 0) {
+        LOGE("Unable to setgroups, aborting: %s\n", strerror(errno));
+        return -1;
+    }
+    if (setgid(AID_SHELL) != 0) {
+        LOGE("Unable to setgid, aborting: %s\n", strerror(errno));
+        return -1;
+    }
+    if (setuid(AID_SHELL) != 0) {
+        LOGE("Unable to setuid, aborting: %s\n", strerror(errno));
+        return -1;
+    }
 
     char path[PATH_MAX], tmp_path[PATH_MAX];
     pid_t gzip_pid = -1;