Description: binder: fix race that allows malicious free of live buffer
References:
 https://source.android.com/security/bulletin/2019-03-01
Notes:
 bwh> The upstream fix is marked for 4.14 onward and I think this was
 bwh> introduced by commit a60b890f607d "binder: remove global binder lock".
Bugs:
upstream: released (4.20-rc5) [7bada55ab50697861eee6bb7d60b41e68a961a9c]
4.19-upstream-stable: released (4.19.7) [553927d6aab993e1297d0c69274cd0c2df5440ca]
4.9-upstream-stable: N/A "Vulnerability introduced later"
3.16-upstream-stable: N/A "Vulnerability introduced later"
sid: released (4.19.9-1)
4.9-stretch-security: N/A "Vulnerability introduced later"
3.16-jessie-security: N/A "Vulnerability introduced later"