free_task_struct() called too early?

[Chen, Kenneth W]

When a process terminates, it appears that the task structure is freed too
early.  There are memory references to the kernel task area (task_struct and
stack space) after free_task_struct(p) is called.

If I modify the following line in include/asm-i386/processor.h

#define free_task_struct(p)   free_pages((unsigned long) (p), 1) to
#define free_task_struct(p)   memset((void*) (p), 0xf, PAGE_SIZE*2);
free_pages((unsigned long) (p), 1)
then kernel will boot to init and lockup on when first task terminates.

Has anyone looked into or aware of this issue?