Patch "binder: use group leader instead of open thread" has been added to the 4.12-stable tree

Patch "binder: use group leader instead of open thread" has been added to the 4.12-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    binder: use group leader instead of open thread

to the 4.12-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     binder-use-group-leader-instead-of-open-thread.patch
and it can be found in the queue-4.12 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From c4ea41ba195d01c9af66fb28711a16cc97caa9c5 Mon Sep 17 00:00:00 2001
From: Todd Kjos <tkjos@android.com>
Date: Thu, 29 Jun 2017 12:01:36 -0700
Subject: binder: use group leader instead of open thread

From: Todd Kjos <tkjos@android.com>

commit c4ea41ba195d01c9af66fb28711a16cc97caa9c5 upstream.

The binder allocator assumes that the thread that
called binder_open will never die for the lifetime of
that proc. That thread is normally the group_leader,
however it may not be. Use the group_leader instead
of current.

Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/android/binder.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -3460,8 +3460,8 @@ static int binder_open(struct inode *nod
 	proc = kzalloc(sizeof(*proc), GFP_KERNEL);
 	if (proc == NULL)
 		return -ENOMEM;
-	get_task_struct(current);
-	proc->tsk = current;
+	get_task_struct(current->group_leader);
+	proc->tsk = current->group_leader;
 	INIT_LIST_HEAD(&proc->todo);
 	init_waitqueue_head(&proc->wait);
 	proc->default_priority = task_nice(current);


Patches currently in stable-queue which might be from tkjos@android.com are

queue-4.12/binder-use-group-leader-instead-of-open-thread.patch
queue-4.12/revert-android-binder-sanity-check-at-binder-ioctl.patch