batman-adv/patches/0009-batman-adv-fix-kernel-crash-due-to-missing-NULL-chec.patch

   1 From 2c2dfd886a400057ccbc66f1507c94ed909d2a89 Mon Sep 17 00:00:00 2001
   2 From: Marek Lindner <mareklindner@neomailbox.ch>
   3 Date: Tue, 9 Jun 2015 21:24:36 +0800
   4 Subject: [PATCH 09/17] batman-adv: fix kernel crash due to missing NULL checks
   5
   6 batadv_softif_vlan_get() may return NULL which has to be verified
   7 by the caller.
   8
   9 Fixes: 9729d20 ("batman-adv: fix TT VLAN inconsistency on VLAN re-add")
  10
  11 Reported-by: Ryan Thompson <ryan@eero.com>
  12 Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
  13 Acked-by: Antonio Quartulli <antonio@meshcoding.com>
  14 ---
  15  soft-interface.c    |  3 +++
  16  translation-table.c | 19 +++++++++++++++----
  17  2 files changed, 18 insertions(+), 4 deletions(-)
  18
  19 diff --git a/soft-interface.c b/soft-interface.c
  20 index da89336..7841a4b 100644
  21 --- a/soft-interface.c
  22 +++ b/soft-interface.c
  23 @@ -455,6 +455,9 @@ out:
  24   */
  25  void batadv_softif_vlan_free_ref(struct batadv_softif_vlan *vlan)
  26  {
  27 +       if (!vlan)
  28 +               return;
  29 +
  30         if (atomic_dec_and_test(&vlan->refcount)) {
  31                 spin_lock_bh(&vlan->bat_priv->softif_vlan_list_lock);
  32                 hlist_del_rcu(&vlan->list);
  33 diff --git a/translation-table.c b/translation-table.c
  34 index e95a424..807a4e6 100644
  35 --- a/translation-table.c
  36 +++ b/translation-table.c
  37 @@ -26,6 +26,7 @@
  38  #include "bridge_loop_avoidance.h"
  39  #include "multicast.h"
  40
  41 +#include <linux/bug.h>
  42  #include <linux/crc32c.h>
  43
  44  /* hash class keys */
  45 @@ -575,6 +576,9 @@ bool batadv_tt_local_add(struct net_device *soft_iface, const uint8_t *addr,
  46
  47         /* increase the refcounter of the related vlan */
  48         vlan = batadv_softif_vlan_get(bat_priv, vid);
  49 +       if (WARN(!vlan, "adding TT local entry %pM to non-existent VLAN %d",
  50 +                addr, BATADV_PRINT_VID(vid)))
  51 +               goto out;
  52
  53         batadv_dbg(BATADV_DBG_TT, bat_priv,
  54                    "Creating new local tt entry: %pM (vid: %d, ttvn: %d)\n",
  55 @@ -1047,6 +1051,9 @@ uint16_t batadv_tt_local_remove(struct batadv_priv *bat_priv,
  56
  57         /* decrease the reference held for this vlan */
  58         vlan = batadv_softif_vlan_get(bat_priv, vid);
  59 +       if (!vlan)
  60 +               goto out;
  61 +
  62         batadv_softif_vlan_free_ref(vlan);
  63         batadv_softif_vlan_free_ref(vlan);
  64
  65 @@ -1147,8 +1154,10 @@ static void batadv_tt_local_table_free(struct batadv_priv *bat_priv)
  66                         /* decrease the reference held for this vlan */
  67                         vlan = batadv_softif_vlan_get(bat_priv,
  68                                                       tt_common_entry->vid);
  69 -                       batadv_softif_vlan_free_ref(vlan);
  70 -                       batadv_softif_vlan_free_ref(vlan);
  71 +                       if (vlan) {
  72 +                               batadv_softif_vlan_free_ref(vlan);
  73 +                               batadv_softif_vlan_free_ref(vlan);
  74 +                       }
  75
  76                         batadv_tt_local_entry_free_ref(tt_local);
  77                 }
  78 @@ -3188,8 +3197,10 @@ static void batadv_tt_local_purge_pending_clients(struct batadv_priv *bat_priv)
  79
  80                         /* decrease the reference held for this vlan */
  81                         vlan = batadv_softif_vlan_get(bat_priv, tt_common->vid);
  82 -                       batadv_softif_vlan_free_ref(vlan);
  83 -                       batadv_softif_vlan_free_ref(vlan);
  84 +                       if (vlan) {
  85 +                               batadv_softif_vlan_free_ref(vlan);
  86 +                               batadv_softif_vlan_free_ref(vlan);
  87 +                       }
  88
  89                         batadv_tt_local_entry_free_ref(tt_local);
  90                 }
  91 --
  92 2.1.4
  93