From d0c5f515c05d05c9d24971695337daf9d6ce409c Mon Sep 17 00:00:00 2001
From: Dianne Hackborn <hackbod@google.com>
Date: Thu, 7 Jun 2012 16:53:59 -0700
Subject: Fix issue #6295373: "Package com.google.android.apps.authenticator2
 has...

...mismatched uid: X on disk, Y in settings" errors on Froyo and Gingerbread

Deal more gracefully with the uid changing in three ways:

1. If the uid on disk has become root, then have installd change it to
   the application's uid.  This is to correct a potential case where
   installd was interrupted while linking or unlinking the libs dir,
   during which it temporarily changes the owner of the dir to root
   so that a malicious app can not get in its way.  So if the uid on
   disk has become root, we assume we can safely just change it back
   to the correct uid.

2. When scaning packages at boot, use the same "delete and rebuild data
   directory" code for third party applications as we have for system
   applications.  This allows us to at least end up in a state where the
   app will run, even if its data is lost.

3. But we really don't want to get in to case 2, so if an application
   update is being installed and we find that the uid we now have for
   the app is different than the one on disk, fail the update.  This will
   protect against for example a developer changing the sharedUserId of
   their app and getting into this bad state.

Bug: 6295373
Change-Id: Ic802fdd818ac62449ff3c61d1fff1aa4d4942f39
---
 cmds/installd/commands.c | 41 +++++++++++++++++++++++++++++++++++++++--
 1 file changed, 39 insertions(+), 2 deletions(-)

(limited to 'cmds/installd/commands.c')

diff --git a/cmds/installd/commands.c b/cmds/installd/commands.c
index 203d180a6439..0bc737185b91 100644
--- a/cmds/installd/commands.c
+++ b/cmds/installd/commands.c
@@ -106,6 +106,43 @@ int renamepkg(const char *oldpkgname, const char *newpkgname)
     return 0;
 }
 
+int fix_uid(const char *pkgname, uid_t uid, gid_t gid)
+{
+    char pkgdir[PKG_PATH_MAX];
+    struct stat s;
+    int rc = 0;
+
+    if ((uid < AID_SYSTEM) || (gid < AID_SYSTEM)) {
+        ALOGE("invalid uid/gid: %d %d\n", uid, gid);
+        return -1;
+    }
+
+    if (create_pkg_path(pkgdir, pkgname, PKG_DIR_POSTFIX, 0)) {
+        ALOGE("cannot create package path\n");
+        return -1;
+    }
+
+    if (stat(pkgdir, &s) < 0) return -1;
+
+    if (s.st_uid != 0 || s.st_gid != 0) {
+        ALOGE("fixing uid of non-root pkg: %s %d %d\n", pkgdir, s.st_uid, s.st_gid);
+        return -1;
+    }
+
+    if (chmod(pkgdir, 0751) < 0) {
+        ALOGE("cannot chmod dir '%s': %s\n", pkgdir, strerror(errno));
+        unlink(pkgdir);
+        return -errno;
+    }
+    if (chown(pkgdir, uid, gid) < 0) {
+        ALOGE("cannot chown dir '%s': %s\n", pkgdir, strerror(errno));
+        unlink(pkgdir);
+        return -errno;
+    }
+
+    return 0;
+}
+
 int delete_user_data(const char *pkgname, uid_t persona)
 {
     char pkgdir[PKG_PATH_MAX];
@@ -950,7 +987,7 @@ int linklib(const char* dataDir, const char* asecLibDir)
 out:
     if (chmod(dataDir, s.st_mode) < 0) {
         ALOGE("failed to chmod '%s': %s\n", dataDir, strerror(errno));
-        return -errno;
+        rc = -errno;
     }
 
     if (chown(dataDir, s.st_uid, s.st_gid) < 0) {
@@ -1027,7 +1064,7 @@ int unlinklib(const char* dataDir)
 out:
     if (chmod(dataDir, s.st_mode) < 0) {
         ALOGE("failed to chmod '%s': %s\n", dataDir, strerror(errno));
-        return -1;
+        rc = -1;
     }
 
     if (chown(dataDir, s.st_uid, s.st_gid) < 0) {
-- 
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