Messages in this thread | | | Date | Sat, 7 Jul 2007 02:13:01 +0200 (CEST) | From | Jiri Kosina <> | Subject | Re: [PATCH][RESEND] PIE randomization |
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On Thu, 5 Jul 2007, Rik van Riel wrote:
> So the original patch has: > #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE) > For some reason(?) it got changed to the clearly buggy: > #define BAD_ADDR(x) ((unsigned long)(x) >= PAGE_MASK) > Jiri's patch undoes that second buggy define, which is very > different from the original that was sent in by you and Ernie.
This is a part of execshield patch, fthe pie-compiled binary executable memory layout randomization was extracted from - see http://people.redhat.com/~mingo/exec-shield/exec-shield-nx-2.6.19.patch
Note that load_elf_interp() in vanilla kernel differs from the execshield's (and pie-randomization.patch) version.
The fix makes the BAD_ADDR check whether the address belongs to the ERR_PTR range, which seems valid for all uses of BAD_ADDR in the patched binfmt_elf.c (do_brk(), elf_map(), do_mmap() etc return valid address or err ptr) ... am I missing something obvious here?
-- Jiri Kosina SUSE Labs - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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