userns: Convert binder ipc to use kuids

Cc: Arve Hjønnevåg <arve@android.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

2 files changed, 7 insertions, 10 deletions

diff --git a/drivers/staging/android/binder.c b/drivers/staging/android/binder.c
index 574e99210c36..8e35d4b2524c 100644
--- a/drivers/staging/android/binder.c
+++ b/drivers/staging/android/binder.c
@@ -47,7 +47,7 @@ static HLIST_HEAD(binder_dead_nodes);
 static struct dentry *binder_debugfs_dir_entry_root;
 static struct dentry *binder_debugfs_dir_entry_proc;
 static struct binder_node *binder_context_mgr_node;
-static uid_t binder_context_mgr_uid = -1;
+static kuid_t binder_context_mgr_uid = INVALID_UID;
 static int binder_last_id;
 static struct workqueue_struct *binder_deferred_workqueue;
 
@@ -356,7 +356,7 @@ struct binder_transaction {
         unsigned int    flags;
         long    priority;
         long    saved_priority;
-        uid_t   sender_euid;
+        kuid_t  sender_euid;
 };
 
 static void
@@ -2427,7 +2427,7 @@ retry:
                 }
                 tr.code = t->code;
                 tr.flags = t->flags;
-                tr.sender_euid = t->sender_euid;
+                tr.sender_euid = from_kuid(current_user_ns(), t->sender_euid);
 
                 if (t->from) {
                         struct task_struct *sender = t->from->proc->tsk;
@@ -2705,12 +2705,12 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
                         ret = -EBUSY;
                         goto err;
                 }
-                if (binder_context_mgr_uid != -1) {
-                        if (binder_context_mgr_uid != current->cred->euid) {
+                if (uid_valid(binder_context_mgr_uid)) {
+                        if (!uid_eq(binder_context_mgr_uid, current->cred->euid)) {
                                 pr_err("binder: BINDER_SET_"
                                        "CONTEXT_MGR bad uid %d != %d\n",
-                                       current->cred->euid,
-                                       binder_context_mgr_uid);
+                                       from_kuid(&init_user_ns, current->cred->euid),
+                                       from_kuid(&init_user_ns, binder_context_mgr_uid));
                                 ret = -EPERM;
                                 goto err;
                         }
diff --git a/init/Kconfig b/init/Kconfig
index 570cd337e961..86910982b94a 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -952,9 +952,6 @@ config UIDGID_CONVERTED
         depends on UFS_FS = n
         depends on XFS_FS = n
 
-        # The rare drivers that won't build
-        depends on ANDROID_BINDER_IPC = n
-
 config UIDGID_STRICT_TYPE_CHECKS
         bool "Require conversions between uid/gids and their internal representation"
         depends on UIDGID_CONVERTED