Re: [PATCH] install_special_mapping skips security_file_mmap check.

[Randy Dunlap]

On Thu, 9 Dec 2010 15:29:42 +0100 Tavis Ormandy wrote:

> Signed-off-by: Tavis Ormandy <taviso@xxxxxxxxxx>
> Acked-by: Kees Cook <kees@xxxxxxxxxx>
> Acked-by: Robert Swiecki <swiecki@xxxxxxxxxx>
> ---
> 
>  fs/exec.c |    7 +++++++
>  mm/mmap.c |    5 +++++
>  2 files changed, 12 insertions(+), 0 deletions(-)
> 
> diff --git a/fs/exec.c b/fs/exec.c
> index d68c378..7e8c4b6 100644
> --- a/fs/exec.c
> +++ b/fs/exec.c
> @@ -275,7 +275,14 @@ static int __bprm_mm_init(struct linux_binprm *bprm)
>     vma->vm_flags = VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP;
>     vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
>     INIT_LIST_HEAD(&vma->anon_vma_chain);
> +
> +   err = security_file_mmap(NULL, 0, 0, 0, vma->vm_start, 1);
> +
> +   if (err)
> +       goto err;
> +
>     err = insert_vm_struct(mm, vma);
> +
>     if (err)
>         goto err;
>  

Uh, something happened to the tabs at the beginning of each line...
I.e., the original file content has been mucked up.


> diff --git a/mm/mmap.c b/mm/mmap.c
> index b179abb..1de3f4b 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -2479,6 +2479,11 @@ int install_special_mapping(struct mm_struct *mm,
>     vma->vm_ops = &special_mapping_vmops;
>     vma->vm_private_data = pages;
>  
> +   if (security_file_mmap(NULL, 0, 0, 0, vma->vm_start, 1)) {
> +       kmem_cache_free(vm_area_cachep, vma);
> +       return -EPERM;
> +   }
> +
>     if (unlikely(insert_vm_struct(mm, vma))) {
>         kmem_cache_free(vm_area_cachep, vma);
>         return -ENOMEM;
> 
> 
> -- 
> -------------------------------------


---
~Randy
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