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;a=summary
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@xxxxxxxxxxxxxxx> know about it.
>From f88982679f54f75daa5b8eff3da72508f1e7422f Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers@xxxxxxxxxx>
Date: Tue, 30 Jan 2018 23:11:24 -0800
Subject: binder: check for binder_thread allocation failure in binder_poll()
From: Eric Biggers <ebiggers@xxxxxxxxxx>
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@xxxxxxxxxxxxxxxx>
Fixes: 457b9a6f09f0 ("Staging: android: add binder driver")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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@xxxxxxxxxx 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