From 0c8fed7d9e198347cd9b5ece3dd0010dc507957d Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 11 Sep 2014 09:19:31 -0700 Subject: [PATCH] x86/kaslr: Avoid the setup_data area when picking location 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 Tested-by: Baoquan He Cc: Vivek Goyal Cc: Rafael J. Wysocki Cc: Wei Yongjun Cc: Pavel Machek Cc: Linus Torvalds Link: http://lkml.kernel.org/r/20140911161931.GA12001@www.outflux.net Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- 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 4dbf967da50d..6cfcf2a2eb93 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; }