Commit f8898267 authored Jan 30, 2018 by Eric Biggers Committed by Greg Kroah-Hartman Feb 16, 2018

binder: check for binder_thread allocation failure in binder_poll()



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: 457b9a6f ("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>

parent 7928b2cb

drivers/android/binder.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -4391,6 +4391,8 @@ static __poll_t binder_poll(struct file *filp,
		bool wait_for_proc_work;

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

		binder_inner_proc_lock(thread->proc);
		thread->looper \|= BINDER_LOOPER_STATE_POLL;

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