releases/3.14.57/ib-cm-fix-rb-tree-duplicate-free-and-use-after-free.patch

   1 From 0ca81a2840f77855bbad1b9f172c545c4dc9e6a4 Mon Sep 17 00:00:00 2001
   2 From: Doron Tsur <doront@mellanox.com>
   3 Date: Sun, 11 Oct 2015 15:58:17 +0300
   4 Subject: IB/cm: Fix rb-tree duplicate free and use-after-free
   5
   6 From: Doron Tsur <doront@mellanox.com>
   7
   8 commit 0ca81a2840f77855bbad1b9f172c545c4dc9e6a4 upstream.
   9
  10 ib_send_cm_sidr_rep could sometimes erase the node from the sidr
  11 (depending on errors in the process). Since ib_send_cm_sidr_rep is
  12 called both from cm_sidr_req_handler and cm_destroy_id, cm_id_priv
  13 could be either erased from the rb_tree twice or not erased at all.
  14 Fixing that by making sure it's erased only once before freeing
  15 cm_id_priv.
  16
  17 Fixes: a977049dacde ('[PATCH] IB: Add the kernel CM implementation')
  18 Signed-off-by: Doron Tsur <doront@mellanox.com>
  19 Signed-off-by: Matan Barak <matanb@mellanox.com>
  20 Signed-off-by: Doug Ledford <dledford@redhat.com>
  21 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  22
  23 ---
  24  drivers/infiniband/core/cm.c |   10 +++++++++-
  25  1 file changed, 9 insertions(+), 1 deletion(-)
  26
  27 --- a/drivers/infiniband/core/cm.c
  28 +++ b/drivers/infiniband/core/cm.c
  29 @@ -860,6 +860,11 @@ retest:
  30         case IB_CM_SIDR_REQ_RCVD:
  31                 spin_unlock_irq(&cm_id_priv->lock);
  32                 cm_reject_sidr_req(cm_id_priv, IB_SIDR_REJECT);
  33 +               spin_lock_irq(&cm.lock);
  34 +               if (!RB_EMPTY_NODE(&cm_id_priv->sidr_id_node))
  35 +                       rb_erase(&cm_id_priv->sidr_id_node,
  36 +                                &cm.remote_sidr_table);
  37 +               spin_unlock_irq(&cm.lock);
  38                 break;
  39         case IB_CM_REQ_SENT:
  40                 ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
  41 @@ -3099,7 +3104,10 @@ int ib_send_cm_sidr_rep(struct ib_cm_id
  42         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
  43
  44         spin_lock_irqsave(&cm.lock, flags);
  45 -       rb_erase(&cm_id_priv->sidr_id_node, &cm.remote_sidr_table);
  46 +       if (!RB_EMPTY_NODE(&cm_id_priv->sidr_id_node)) {
  47 +               rb_erase(&cm_id_priv->sidr_id_node, &cm.remote_sidr_table);
  48 +               RB_CLEAR_NODE(&cm_id_priv->sidr_id_node);
  49 +       }
  50         spin_unlock_irqrestore(&cm.lock, flags);
  51         return 0;
  52