4.9-stable review patch. If anyone has any objections, please let me know.
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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 @@ -2628,6 +2628,8 @@ 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;