From f88982679f54f75daa5b8eff3da72508f1e7422f Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Tue, 30 Jan 2018 23:11:24 -0800 Subject: [PATCH] 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 Fixes: 457b9a6f09f0 ("Staging: android: add binder driver") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers Signed-off-by: Greg Kroah-Hartman --- drivers/android/binder.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 15e3d3c2260d..ad5e662e3e14 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -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; -- 2.30.2