On Tue, May 13, 2014 at 11:35:42PM -0400, Sasha Levin wrote:
> A file reference should be held while a file is mmaped, otherwise it might
> be freed while being used.
>
> Suggested-by: Hugh Dickins <hughd@xxxxxxxxxx>
> Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
Sorry, again. :-/
Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
> ---
> mm/mmap.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/mm/mmap.c b/mm/mmap.c
> index 2a0e0a8..da3c212 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -2593,6 +2593,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
> struct vm_area_struct *vma;
> unsigned long populate = 0;
> unsigned long ret = -EINVAL;
> + struct file *file;
>
> pr_warn_once("%s (%d) uses deprecated remap_file_pages() syscall. "
> "See Documentation/vm/remap_file_pages.txt.\n",
> @@ -2636,8 +2637,10 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
> munlock_vma_pages_range(vma, start, start + size);
> }
>
> + file = get_file(vma->vm_file);
> ret = do_mmap_pgoff(vma->vm_file, start, size,
> prot, flags, pgoff, &populate);
> + fput(file);
> out:
> up_write(&mm->mmap_sem);
> if (populate)
> --
> 1.7.10.4
>
> --
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--
Kirill A. Shutemov
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