Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 3.16 216/357] x86/kaslr: Avoid the setup_data area when picking location | Date | Fri, 3 Oct 2014 14:30:02 -0700 |
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3.16-stable review patch. If anyone has any objections, please let me know.
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From: Kees Cook <keescook@chromium.org>
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 <keescook@chromium.org> Tested-by: Baoquan He <bhe@redhat.com> 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- 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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