Android before 2.3 does not properly restrict access to the system property space, which allows local applications to bypass the application sandbox and gain privileges, as demonstrated by psneuter and KillingInTheNameOf, related to the use of Android shared memory (ashmem) and ASHMEM_SET_PROT_MASK.
android.git.kernel.org/?p=kernel/common.git%3Ba=commit%3Bh=c98a285075f26e2b17a5baa2cb3eb6356a75597e
android.git.kernel.org/?p=platform/system/core.git%3Ba=commit%3Bh=25b15be9120bcdaa0aba622c67ad2c835d9e91ca
c-skills.blogspot.com/2011/01/adb-trickery-again.html
forum.xda-developers.com/wiki/index.php?title=HTC_Vision#Rooting_the_G2
groups.google.com/group/android-security-discuss/browse_thread/thread/15f97658c88d6827/e86db04652651971?show_docid=e86db04652651971
github.com/tmzt/g2root-kmod/tree/scotty2/scotty2