3.16-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Kees Cook <[email protected]>

commit 0cacbfbeb5077b63d5d3cf6df88b14ac12ad584b upstream.

The KASLR location-choosing logic needs to avoid the setup_data
list memory areas as well. Without this, it would be possible to
have the ASLR position stomp on the memory, ultimately causing
the boot to fail.

Signed-off-by: Kees Cook <[email protected]>
Tested-by: Baoquan He <[email protected]>
Cc: Vivek Goyal <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: Wei Yongjun <[email protected]>
Cc: Pavel Machek <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 arch/x86/boot/compressed/aslr.c |   15 +++++++++++++++
 1 file changed, 15 insertions(+)

--- a/arch/x86/boot/compressed/aslr.c
+++ b/arch/x86/boot/compressed/aslr.c
@@ -183,12 +183,27 @@ static void mem_avoid_init(unsigned long
 static bool mem_avoid_overlap(struct mem_vector *img)
 {
        int i;
+       struct setup_data *ptr;
 
        for (i = 0; i < MEM_AVOID_MAX; i++) {
                if (mem_overlaps(img, &mem_avoid[i]))
                        return true;
        }
 
+       /* Avoid all entries in the setup_data linked list. */
+       ptr = (struct setup_data *)(unsigned long)real_mode->hdr.setup_data;
+       while (ptr) {
+               struct mem_vector avoid;
+
+               avoid.start = (u64)ptr;
+               avoid.size = sizeof(*ptr) + ptr->len;
+
+               if (mem_overlaps(img, &avoid))
+                       return true;
+
+               ptr = (struct setup_data *)(unsigned long)ptr->next;
+       }
+
        return false;
 }
 


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