Commit aed86f8a authored by Schspa Shi's avatar Schspa Shi Committed by Greg Kroah-Hartman
Browse files

binder: fix atomic sleep when get extended error 



binder_inner_proc_lock(thread->proc) is a spin lock, copy_to_user can't
be called with in this lock.

Copy it as a local variable to fix it.

Fixes: bd32889e ("binder: add BINDER_GET_EXTENDED_ERROR ioctl")
Reported-by: default avatar <syzbot+46fff6434a7f968ecb39@syzkaller.appspotmail.com>
Reviewed-by: default avatarCarlos Llamas <cmllamas@google.com>
Signed-off-by: default avatarSchspa Shi <schspa@gmail.com>
Link: https://lore.kernel.org/r/20220518011754.49348-1-schspa@gmail.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent dafa5e9a

drivers/android/binder.c

+6 −9
Original line number Diff line number Diff line
@@ -5163,18 +5163,15 @@ static int binder_ioctl_get_freezer_info( 
static int binder_ioctl_get_extended_error(struct binder_thread *thread,

					   void __user *ubuf)

{

	struct binder_extended_error *ee = &thread->ee;

	struct binder_extended_error ee;



	binder_inner_proc_lock(thread->proc);

	if (copy_to_user(ubuf, ee, sizeof(*ee))) {

	ee = thread->ee;

	binder_set_extended_error(&thread->ee, 0, BR_OK, 0);

	binder_inner_proc_unlock(thread->proc);

		return -EFAULT;

	}



	ee->id = 0;

	ee->command = BR_OK;

	ee->param = 0;

	binder_inner_proc_unlock(thread->proc);

	if (copy_to_user(ubuf, &ee, sizeof(ee)))

		return -EFAULT;



	return 0;

}