Commit-ID: 4abf061bf87bbd856c8d60199b2fba8b8f9b9fd6 Gitweb: http://git.kernel.org/tip/4abf061bf87bbd856c8d60199b2fba8b8f9b9fd6 Author: Yinghai Lu <ying...@kernel.org> AuthorDate: Thu, 28 Apr 2016 17:09:08 -0700 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Fri, 29 Apr 2016 11:03:30 +0200
x86/boot: Correctly bounds-check relocations Relocation handling performs bounds checking on the resulting calculated addresses. The existing code uses output_len (VO size plus relocs size) as the max address. This is not right since the max_addr check should stop at the end of VO and exclude bss, brk, etc, which follows. The valid range should be VO [_text, __bss_start] in the loaded physical address space. This patch adds an export for __bss_start in voffset.h and uses it to set the correct limit for max_addr. Signed-off-by: Yinghai Lu <ying...@kernel.org> [ Rewrote the changelog. ] Signed-off-by: Kees Cook <keesc...@chromium.org> Cc: Andrew Morton <a...@linux-foundation.org> Cc: Andy Lutomirski <l...@amacapital.net> Cc: Andy Lutomirski <l...@kernel.org> Cc: Baoquan He <b...@redhat.com> Cc: Borislav Petkov <b...@alien8.de> Cc: Brian Gerst <brge...@gmail.com> Cc: Dave Young <dyo...@redhat.com> Cc: Denys Vlasenko <dvlas...@redhat.com> Cc: H. Peter Anvin <h...@zytor.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Vivek Goyal <vgo...@redhat.com> Cc: lasse.col...@tukaani.org Link: http://lkml.kernel.org/r/1461888548-32439-7-git-send-email-keesc...@chromium.org Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/boot/compressed/Makefile | 2 +- arch/x86/boot/compressed/misc.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index adef26d..75f2233 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -57,7 +57,7 @@ LDFLAGS_vmlinux := -T hostprogs-y := mkpiggy HOST_EXTRACFLAGS += -I$(srctree)/tools/include -sed-voffset := -e 's/^\([0-9a-fA-F]*\) [ABCDGRSTVW] \(_text\|_end\)$$/\#define VO_\2 _AC(0x\1,UL)/p' +sed-voffset := -e 's/^\([0-9a-fA-F]*\) [ABCDGRSTVW] \(_text\|__bss_start\|_end\)$$/\#define VO_\2 _AC(0x\1,UL)/p' quiet_cmd_voffset = VOFFSET $@ cmd_voffset = $(NM) $< | sed -n $(sed-voffset) > $@ diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index bee6238..8f0253d 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -191,7 +191,7 @@ static void handle_relocations(void *output, unsigned long output_len) int *reloc; unsigned long delta, map, ptr; unsigned long min_addr = (unsigned long)output; - unsigned long max_addr = min_addr + output_len; + unsigned long max_addr = min_addr + (VO___bss_start - VO__text); /* * Calculate the delta between where vmlinux was linked to load
