Description
The vold volume manager daemon on Android 3.0 and 2.x before 2.3.4 trusts messages that are received from a PF_NETLINK socket, which allows local users to execute arbitrary code and gain root privileges via a negative index that bypasses a maximum-only signed integer check in the DirectVolume::handlePartitionAdded method, which triggers memory corruption, as demonstrated by Gingerbreak.
References
- http://android.git.kernel.org/?p=platform/system/netd.git%3Ba=commit%3Bh=79b579c92afc08ab12c0a5788d61f2dd2934836f
- http://android.git.kernel.org/?p=platform/system/core.git%3Ba=commit%3Bh=b620a0b1c7ae486e979826200e8e441605b0a5d6
- http://c-skills.blogspot.com/2011/04/yummy-yummy-gingerbreak.html
- http://androidcommunity.com/gingerbreak-root-for-gingerbread-app-20110421/
- http://android.git.kernel.org/?p=platform/system/vold.git%3Ba=commit%3Bh=c51920c82463b240e2be0430849837d6fdc5352e
- http://xorl.wordpress.com/2011/04/28/android-vold-mpartminors-signedness-issue/
- android-vold-priv-escalation(67977) vdb-entry
- http://www.androidpolice.com/2011/05/03/google-patches-gingerbreak-exploit-but-dont-worry-we-still-have-root-for-now/
- http://forum.xda-developers.com/showthread.php?t=1044765