Messages in this thread | | | Date | Wed, 1 Oct 2014 11:08:56 -0700 | Subject | Re: [PATCH] x86, kaslr: avoid setup_data when picking location | From | Kees Cook <> |
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On Wed, Oct 1, 2014 at 11:01 AM, H. Peter Anvin <hpa@zytor.com> wrote: > On 09/11/2014 09:19 AM, Kees Cook wrote: >> --- 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; >> } >> >> > > The use of (u64) in the assignment to avoid.start gives a nuisance > warning on 32 bits.
Ah, good catch! This should be (unsigned long), I think. Shall I send a follow-up patch, or do you want to fix this directly?
-Kees
-- Kees Cook Chrome OS Security
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