Re: {2.6.22.y} CVE-2007-6434

[Oliver Pinter]

http://nvd.nist.gov/nvd.cfm?cvename=CVE-2007-6434

On 2/4/08, Oliver Pinter <oliver.pntr@xxxxxxxxx> wrote:
> mainline: ecaf18c15aac8bb9bed7b7aa0e382fe252e275d5
>
> --->8---
> commit ecaf18c15aac8bb9bed7b7aa0e382fe252e275d5
> Author: Eric Paris <eparis@xxxxxxxxxx>
> Date:   Tue Dec 4 23:45:31 2007 -0800
>
>     VM/Security: add security hook to do_brk
>
>     Given a specifically crafted binary do_brk() can be used to get low
> pages
>     available in userspace virtual memory and can thus be used to circumvent
>     the mmap_min_addr low memory protection.  Add security checks in
> do_brk().
>
>     Signed-off-by: Eric Paris <eparis@xxxxxxxxxx>
>     Acked-by: Alan Cox <alan@xxxxxxxxxx>
>     Cc: Stephen Smalley <sds@xxxxxxxxxxxxx>
>     Cc: James Morris <jmorris@xxxxxxxxx>
>     Cc: Chris Wright <chrisw@xxxxxxxxxxxx>
>     Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
>     Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
>
> diff --git a/mm/mmap.c b/mm/mmap.c
> index facc1a7..acfc13f 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -1934,6 +1934,10 @@ unsigned long do_brk(unsigned long addr, unsigned
> long le
>         if (is_hugepage_only_range(mm, addr, len))
>                 return -EINVAL;
>
> +       error = security_file_mmap(0, 0, 0, 0, addr, 1);
> +       if (error)
> +               return error;
> +
>         flags = VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags;
>
>         error = arch_mmap_check(addr, len, flags);
> ---8<---
> --
> Thanks,
> Oliver
>


-- 
Thanks,
Oliver
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