tree ce6b61f5023d0a173a7b606df9b3edae217e2c22
parent 17c9cf4b63cd695a13797c04865e65b0bc64e17d
author Jasraj Bedi <jasrajb@google.com> 1591407725 +0000
committer Anis Assi <anisassi@google.com> 1605210328 -0800

RESTRICT AUTOMERGE
ANDROID: Fix negative stack write in sgdisk

A maliciously formatted USB or SD Card device when inserted into an Android device could crash sgdisk. This crash occurs because sgdisk does does not validate the number of cyclic partitions, which leads to an integer underflow ultimately causing a negative indexed stack write.

Fix this by making sure the number of partitions don't go negative.

After the fix, sgdisk detects the broken GPT and partitions it correctly

Author: jasrajb@google.com
Bug: 158063095
Test: before fix, sgdisk crashed when USB with malicious GPT was inserted
Test: after fix, sgdisk didn't crash
Test: went through the "formatting" wizard with a malicious GPT and sgdisk successfully reformatted it to vfat
Change-Id: Ie0257a68f6a0140b98fb7d104dc2ffd1f5c2afde
(cherry picked from commit a96e0e16dd686338254e1c82b3621d0ce5847e36)