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

binder: check for binder_thread allocation failure in binder_poll()

to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: binder-check-for-binder_thread-allocation-failure-in-binder_poll.patch and it can be found in the queue-4.4 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 f88982679f54f75daa5b8eff3da72508f1e7422f Mon Sep 17 00:00:00 2001

From: Eric Biggers ebiggers@google.com Date: Tue, 30 Jan 2018 23:11:24 -0800 Subject: binder: check for binder_thread allocation failure in binder_poll()

From: Eric Biggers ebiggers@google.com

commit f88982679f54f75daa5b8eff3da72508f1e7422f upstream.

If the kzalloc() in binder_get_thread() fails, binder_poll() dereferences the resulting NULL pointer.

Fix it by returning POLLERR if the memory allocation failed.

This bug was found by syzkaller using fault injection.

Reported-by: syzbot syzkaller@googlegroups.com Fixes: 457b9a6f09f0 ("Staging: android: add binder driver") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers ebiggers@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

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

--- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -2622,6 +2622,8 @@ static unsigned int binder_poll(struct f binder_lock(__func__);

thread = binder_get_thread(proc); + if (!thread) + return POLLERR;

wait_for_proc_work = thread->transaction_stack == NULL && list_empty(&thread->todo) && thread->return_error == BR_OK;

Patches currently in stable-queue which might be from ebiggers@google.com are

queue-4.4/crypto-x86-twofish-3way-fix-rbp-usage.patch queue-4.4/binder-check-for-binder_thread-allocation-failure-in-binder_poll.patch