On Fri, Nov 12, 2021 at 05:11:38PM +0100, Greg KH wrote:

On Wed, Nov 10, 2021 at 02:59:10PM -0800, Todd Kjos wrote:

quoted

commit 52f88693378a58094c538662ba652aff0253c4fe 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: 79af73079d75 ("Add security hooks to binder and implement the hooks for SELinux.")
Suggested-by: Jann Horn <jannh@google.com>
Signed-off-by: Todd Kjos <redacted>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Change-Id: Id7157515d2b08f11683aeb8ad9b8f1da075d34e7
---
 drivers/android/binder.c  | 18 +++++++++---------
 include/linux/lsm_hooks.h | 32 ++++++++++++++++----------------
 include/linux/security.h  | 28 ++++++++++++++--------------
 security/security.c       | 14 +++++++-------
 security/selinux/hooks.c  | 31 +++++++++++++------------------
 5 files changed, 59 insertions(+), 64 deletions(-)

This doesn't apply at all.  I've applied patch 1/2 here, but can you
redo this one and submit it again?

Ugh, nope, my fault, sorry, this worked just fine.

It's been a long day...

greg k-h