diff options
| author | Sasha Levin <sasha.levin@oracle.com> | 2014-05-22 10:54:39 +1000 |
|---|---|---|
| committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2014-05-27 18:24:35 +1000 |
| commit | 11a7f25c1a9da4857679b81b3f3b87835c4beea2 (patch) | |
| tree | 0efa94e942bc7230233394822963cc83a15d78e2 | |
| parent | 3386a1e8d1a2036633a17e82c740658cbf330e12 (diff) | |
mm: remap_file_pages: grab file ref to prevent race while mmaping
A file reference should be held while a file is mmaped, otherwise it might
be freed while being used.
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Suggested-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | mm/mmap.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index 7564c4f34248..bd80310e0c59 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2590,6 +2590,7 @@ 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", @@ -2633,8 +2634,10 @@ 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) |