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authorKees Cook <keescook@chromium.org>2014-09-11 20:19:31 +0400
committerIngo Molnar <mingo@kernel.org>2014-09-19 15:04:29 +0400
commit0cacbfbeb5077b63d5d3cf6df88b14ac12ad584b (patch)
tree9bb11c6c1601404990f7ed17b3573c4d155b38f3
parent43657ffb79eba5234333d8657457774c0d3bff46 (diff)
downloadlinux-0cacbfbeb5077b63d5d3cf6df88b14ac12ad584b.tar.xz
x86/kaslr: Avoid the setup_data area when picking location
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 <keescook@chromium.org> Tested-by: Baoquan He <bhe@redhat.com> Cc: stable@vger.kernel.org Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Cc: Pavel Machek <pavel@ucw.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140911161931.GA12001@www.outflux.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--arch/x86/boot/compressed/aslr.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/x86/boot/compressed/aslr.c b/arch/x86/boot/compressed/aslr.c
index fc6091abedb7..d39189ba7f8e 100644
--- 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 input, unsigned long input_size,
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;
}