releases/4.9.126/pnfs-blocklayout-off-by-one-in-bl_map_stripe.patch

   1 From 0914bb965e38a055e9245637aed117efbe976e91 Mon Sep 17 00:00:00 2001
   2 From: Dan Carpenter <dan.carpenter@oracle.com>
   3 Date: Wed, 4 Jul 2018 12:59:58 +0300
   4 Subject: pnfs/blocklayout: off by one in bl_map_stripe()
   5
   6 From: Dan Carpenter <dan.carpenter@oracle.com>
   7
   8 commit 0914bb965e38a055e9245637aed117efbe976e91 upstream.
   9
  10 "dev->nr_children" is the number of children which were parsed
  11 successfully in bl_parse_stripe().  It could be all of them and then, in
  12 that case, it is equal to v->stripe.volumes_count.  Either way, the >
  13 should be >= so that we don't go beyond the end of what we're supposed
  14 to.
  15
  16 Fixes: 5c83746a0cf2 ("pnfs/blocklayout: in-kernel GETDEVICEINFO XDR parsing")
  17 Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
  18 Reviewed-by: Christoph Hellwig <hch@lst.de>
  19 Cc: stable@vger.kernel.org # 3.17+
  20 Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
  21 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  22
  23 ---
  24  fs/nfs/blocklayout/dev.c |    2 +-
  25  1 file changed, 1 insertion(+), 1 deletion(-)
  26
  27 --- a/fs/nfs/blocklayout/dev.c
  28 +++ b/fs/nfs/blocklayout/dev.c
  29 @@ -203,7 +203,7 @@ static bool bl_map_stripe(struct pnfs_bl
  30         chunk = div_u64(offset, dev->chunk_size);
  31         div_u64_rem(chunk, dev->nr_children, &chunk_idx);
  32
  33 -       if (chunk_idx > dev->nr_children) {
  34 +       if (chunk_idx >= dev->nr_children) {
  35                 dprintk("%s: invalid chunk idx %d (%lld/%lld)\n",
  36                         __func__, chunk_idx, offset, dev->chunk_size);
  37                 /* error, should not happen */