Kernel memory write via ROP gadget

Evasi0n cannot set the destination pointer in a memmove() operation to an arbitrary value because the vtable pointer is necessary to call the wanted function. This problem is solved by searching for a STR R1, [R2]; BX LR gadget in memory and that is being used to write four bytes at a time. With this all patches can be made.

See also

• Jailbreak Patches (like sb_evaluate() and task_for_pid())

References

• Analysis by kernelpool