Messages in this thread Patch in this message |  | | | Date | Wed, 6 Feb 2008 15:54:01 -0800 | | From | Greg KH <> | | Subject | [patch 57/73] security: protect from stack expantion into low vm addresses |
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2.6.23-stable review patch. If anyone has any objections, please let us know. ------------------ From: Eric Paris <eparis@redhat.com> patch 8869477a49c3e99def1fcdadd6bbc407fea14b45 in mainline.
Add security checks to make sure we are not attempting to expand the stack into memory protected by mmap_min_addr
Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- mm/mmap.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1619,6 +1619,12 @@ static inline int expand_downwards(struc */ if (unlikely(anon_vma_prepare(vma))) return -ENOMEM; + + address &= PAGE_MASK; + error = security_file_mmap(0, 0, 0, 0, address, 1); + if (error) + return error; + anon_vma_lock(vma); /* @@ -1626,8 +1632,6 @@ static inline int expand_downwards(struc * is required to hold the mmap_sem in read mode. We need the * anon_vma lock to serialize against concurrent expand_stacks. */ - address &= PAGE_MASK; - error = 0; /* Somebody else might have raced and expanded it already */ if (address < vma->vm_start) { --
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