tree 76c7885516deb0f9159cc8684bd35558cf283e7c
parent b756e7ee8fa23e0c30f89ef1046d58aa6f82ea07
author Todd Kjos <tkjos@google.com> 1634057772 -0700
committer Karsten Tausche <karsten@fairphone.com> 1648458789 +0200

UPSTREAM: binder: use euid from cred instead of using task

commit 29bc22ac5e5bc63275e850f0c8fc549e3d0e306b upstream.

Save the 'struct cred' associated with a binder process
at initial open to avoid potential race conditions
when converting to an euid.

Set a transaction's sender_euid from the 'struct cred'
saved at binder_open() instead of looking up the euid
from the binder proc's 'struct task'. This ensures
the euid is associated with the security context that
of the task that opened binder.

Cc: stable@vger.kernel.org # 4.4+
Fixes: 457b9a6f09f0 ("Staging: android: add binder driver")
Signed-off-by: Todd Kjos <tkjos@google.com>
Suggested-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Suggested-by: Jann Horn <jannh@google.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Change-Id: I91922e7f359df5901749f1b09094c3c68d45aed4
Bug: 200688826
Signed-off-by: Todd Kjos <tkjos@google.com>
Issue: FP3SEC-266
(cherry picked from commit a0e450acb13f84048cdd9e863df0e2c45653635a)