releases/5.0.19/dm-mpath-always-free-attached_handler_name-in-parse_path.patch

   1 From 940bc471780b004a5277c1931f52af363c2fc9da Mon Sep 17 00:00:00 2001
   2 From: Martin Wilck <mwilck@suse.com>
   3 Date: Mon, 29 Apr 2019 11:48:15 +0200
   4 Subject: dm mpath: always free attached_handler_name in parse_path()
   5
   6 From: Martin Wilck <mwilck@suse.com>
   7
   8 commit 940bc471780b004a5277c1931f52af363c2fc9da upstream.
   9
  10 Commit b592211c33f7 ("dm mpath: fix attached_handler_name leak and
  11 dangling hw_handler_name pointer") fixed a memory leak for the case
  12 where setup_scsi_dh() returns failure. But setup_scsi_dh may return
  13 success and not "use" attached_handler_name if the
  14 retain_attached_hwhandler flag is not set on the map. As setup_scsi_sh
  15 properly "steals" the pointer by nullifying it, freeing it
  16 unconditionally in parse_path() is safe.
  17
  18 Fixes: b592211c33f7 ("dm mpath: fix attached_handler_name leak and dangling hw_handler_name pointer")
  19 Cc: stable@vger.kernel.org
  20 Reported-by: Yufen Yu <yuyufen@huawei.com>
  21 Signed-off-by: Martin Wilck <mwilck@suse.com>
  22 Signed-off-by: Mike Snitzer <snitzer@redhat.com>
  23 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  24
  25 ---
  26  drivers/md/dm-mpath.c |    2 +-
  27  1 file changed, 1 insertion(+), 1 deletion(-)
  28
  29 --- a/drivers/md/dm-mpath.c
  30 +++ b/drivers/md/dm-mpath.c
  31 @@ -882,6 +882,7 @@ static struct pgpath *parse_path(struct
  32         if (attached_handler_name || m->hw_handler_name) {
  33                 INIT_DELAYED_WORK(&p->activate_path, activate_path_work);
  34                 r = setup_scsi_dh(p->path.dev->bdev, m, &attached_handler_name, &ti->error);
  35 +               kfree(attached_handler_name);
  36                 if (r) {
  37                         dm_put_device(ti, p->path.dev);
  38                         goto bad;
  39 @@ -896,7 +897,6 @@ static struct pgpath *parse_path(struct
  40
  41         return p;
  42   bad:
  43 -       kfree(attached_handler_name);
  44         free_pgpath(p);
  45         return ERR_PTR(r);
  46  }