stable inclusion
from linux-4.19.218
commit e82f3f9638f17d58e9a217bce127e2376aefcb9d

--------------------------------

commit 52f88693 upstream.

Since binder was integrated with selinux, it has passed
'struct task_struct' associated with the binder_proc
to represent the source and target of transactions.
The conversion of task to SID was then done in the hook
implementations. It turns out that there are race conditions
which can result in an incorrect security context being used.

Fix by using the 'struct cred' saved during binder_open and pass
it to the selinux subsystem.

Cc: stable@vger.kernel.org # 5.14 (need backport for earlier stables)
Fixes: 79af7307 ("Add security hooks to binder and implement the hooks for SELinux.")
Suggested-by: NJann Horn <jannh@google.com>
Signed-off-by: NTodd Kjos <tkjos@google.com>
Acked-by: NCasey Schaufler <casey@schaufler-ca.com>
Signed-off-by: NPaul Moore <paul@paul-moore.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
conflicts:
	drivers/android/binder.c
Signed-off-by: NYongqiang Liu <liuyongqiang13@huawei.com>
Reviewed-by: NXiu Jianfeng <xiujianfeng@huawei.com>
Reviewed-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NLaibin Qiu <qiulaibin@huawei.com>