From: Eric Biggers ebiggers@google.com
This patch has been added to the 4.1 stable tree. If you have any objections, please let us know.
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[ Upstream commit f88982679f54f75daa5b8eff3da72508f1e7422f ]
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 Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- drivers/android/binder.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 235ba1fbabdb..b834278c0c4d 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -2618,6 +2618,8 @@ static unsigned int binder_poll(struct file *filp, 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;