binder: allow freeze notification for dead nodes

binder: allow freeze notification for dead nodes

commit ca63c66935b978441055e3d87d30225267f99329 upstream.

Alice points out that binder_request_freeze_notification() should not
return EINVAL when the relevant node is dead [1]. The node can die at
any point even if the user input is valid. Instead, allow the request
to be allocated but skip the initial notification for dead nodes. This
avoids propagating unnecessary errors back to userspace.

Fixes: d579b04a52a1 ("binder: frozen notification")
Cc: stable@vger.kernel.org
Suggested-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/all/CAH5fLghapZJ4PbbkC8V5A6Zay-_sgTzwVpwqk6RWWUNKKyJC_Q@mail.gmail.com/
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Acked-by: Todd Kjos <tkjos@google.com>
Link: https://lore.kernel.org/r/20240926233632.821189-7-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>