Messages in this thread Patch in this message | | | Date | Thu, 11 Sep 2014 09:19:31 -0700 | From | Kees Cook <> | Subject | [PATCH] x86, kaslr: avoid setup_data 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 --- arch/x86/boot/compressed/aslr.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)
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; } -- 1.9.1
-- Kees Cook Chrome OS Security
| |