commit a56b0b97ddd64a9558975c470ea6d09b4f10575e
author Nick Kralevich <nnk@google.com> Fri Mar 29 10:00:56 2013 -0700
committer Android Git Automerger <android-git-automerger@android.com> Fri Mar 29 10:00:56 2013 -0700
tree 3c63e649c86d1f6fd593d55b342f0ea52432fa73
parent f19e045c58dafbdc46e848ec5a5c935f472dea34
parent 191fe44c972e7f45f4bac1cee27522ae244da498

am 191fe44c: Merge "run-as: Don\'t require CAP_DAC_READ_SEARCH"

* commit '191fe44c972e7f45f4bac1cee27522ae244da498':
  run-as: Don't require CAP_DAC_READ_SEARCH

run-as/package.c

diff --git a/run-as/package.c b/run-as/package.c
index dce132e..27fc1eb 100644
--- a/run-as/package.c
+++ b/run-as/package.c
@@ -80,13 +80,30 @@
     struct stat  st;
     size_t  length = 0;
     void*   address = NULL;
+    gid_t   oldegid;
 
     *filesize = 0;
 
+    /*
+     * Temporarily switch effective GID to allow us to read
+     * the packages file
+     */
+
+    oldegid = getegid();
+    if (setegid(AID_SYSTEM) < 0) {
+        return NULL;
+    }
+
     /* open the file for reading */
     fd = TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
-    if (fd < 0)
+    if (fd < 0) {
         return NULL;
+    }
+
+    /* restore back to our old egid */
+    if (setegid(oldegid) < 0) {
+        goto EXIT;
+    }
 
     /* get its size */
     ret = TEMP_FAILURE_RETRY(fstat(fd, &st));