A basic PoC leak for CVE-2021-28663 (Internal of the Android kernel backdoor vulnerability)
This is a basic PoC for CVE-2021-28663. A design flaw in Mali GPU Android Kernel Driver.
- Create a
GPU_VA
and alsommap
to it so we can virtual addr for phys pages. - Create an alias for pages, but don't do
mmap
sogpu_mapping
remain as 1 - Change flags of
GPU_VA
toBASE_MEM_DONT_NEED
. Mali will make them evictable - Since we have
reg
for aliased page now we can mmap. This will give us RDONLY access from CPU