mmap: call unlink_anon_vmas() in __split_vma() in case of error

If __split_vma fails because of an out of memory condition the
anon_vma_chain isn't teardown and freed potentially leading to rmap walks
accessing freed vma information plus there's a memleak.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Johannes Weiner <jweiner@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/mmap.c b/mm/mmap.c
index 6128dc8e5ede709cada129438fbac101895aa09d..00161a48a45100c611ebaa053f0b1f1486d09f29 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2009,6 +2009,7 @@ static int __split_vma(struct mm_struct * mm, struct vm_area_struct * vma,
                        removed_exe_file_vma(mm);
                fput(new->vm_file);
        }
+       unlink_anon_vmas(new);
  out_free_mpol:
        mpol_put(pol);
  out_free_vma: