tree cc8a72212f2e7995608fc829a3b4c039b94012c6
parent dbeeb0a5d058351258394f300aa2a55068804204
author Daniel Rosenberg <drosen@google.com> 1486183026 -0800
committer John Dias <joaodias@google.com> 1487192021 +0000

ANDROID: ion: Protect kref from userspace manipulation

This separates the kref for ion handles into two components.
Userspace requests through the ioctl will hold at most one
reference to the internally used kref. All additional requests
will increment a separate counter, and the original reference is
only put once that counter hits 0. This protects the kernel from
a poorly behaving userspace.

Bug: 34276203

Change-Id: Ibc36bc4405788ed0fea7337b541cad3be2b934c0
Signed-off-by: Daniel Rosenberg <drosen@google.com>