batman-adv: Merge bugfixes from 2019.5

[feed/routing.git] / batman-adv / patches / 0070-batman-adv-Avoid-free-alloc-race-when-handling-OGM2-.patch

diff --git a/batman-adv/patches/0070-batman-adv-Avoid-free-alloc-race-when-handling-OGM2-.patch b/batman-adv/patches/0070-batman-adv-Avoid-free-alloc-race-when-handling-OGM2-.patch
new file mode 100644 (file)
index 0000000..d545a13
--- /dev/null
+++ b/batman-adv/patches/0070-batman-adv-Avoid-free-alloc-race-when-handling-OGM2-.patch
@@ -0,0 +1,117 @@
+From: Sven Eckelmann <sven@narfation.org>
+Date: Thu, 3 Oct 2019 17:02:01 +0200
+Subject: batman-adv: Avoid free/alloc race when handling OGM2 buffer
+
+A B.A.T.M.A.N. V virtual interface has an OGM2 packet buffer which is
+initialized using data from the RTNL lock protected netdevice notifier and
+other rtnetlink related hooks. It is sent regularly via various slave
+interfaces of the batadv virtual interface and in this process also
+modified (realloced) to integrate additional state information via TVLV
+containers.
+
+It must be avoided that the worker item is executed without a common lock
+with the netdevice notifier/rtnetlink helpers. Otherwise it can either
+happen that half modified data is sent out or the functions modifying the
+OGM2 buffer try to access already freed memory regions.
+
+Fixes: 632835348e65 ("batman-adv: OGMv2 - add basic infrastructure")
+Signed-off-by: Sven Eckelmann <sven@narfation.org>
+
+Origin: upstream, https://git.open-mesh.org/batman-adv.git/commit/14ee24576213ff02272b7f8d975c7c61d5448aa2
+
+diff --git a/net/batman-adv/bat_v_ogm.c b/net/batman-adv/bat_v_ogm.c
+index 5f4fe1889053d4ea7624e4500dcefe2601371024..f5feaa8c4fd228228fea519771e2c9e123b10345 100644
+--- a/net/batman-adv/bat_v_ogm.c
++++ b/net/batman-adv/bat_v_ogm.c
+@@ -32,6 +32,7 @@
+ #include <linux/random.h>
+ #include <linux/rculist.h>
+ #include <linux/rcupdate.h>
++#include <linux/rtnetlink.h>
+ #include <linux/skbuff.h>
+ #include <linux/slab.h>
+ #include <linux/stddef.h>
+@@ -127,14 +128,12 @@ static void batadv_v_ogm_send_to_if(struct sk_buff *skb,
+ }
+ 
+ /**
+- * batadv_v_ogm_send - periodic worker broadcasting the own OGM
+- * @work: work queue item
++ * batadv_v_ogm_send_softif() - periodic worker broadcasting the own OGM
++ *  @bat_priv: the bat priv with all the soft interface information
+  */
+-static void batadv_v_ogm_send(struct work_struct *work)
++static void batadv_v_ogm_send_softif(struct batadv_priv *bat_priv)
+ {
+       struct batadv_hard_iface *hard_iface;
+-      struct batadv_priv_bat_v *bat_v;
+-      struct batadv_priv *bat_priv;
+       struct batadv_ogm2_packet *ogm_packet;
+       struct sk_buff *skb, *skb_tmp;
+       unsigned char *ogm_buff, *pkt_buff;
+@@ -142,8 +141,7 @@ static void batadv_v_ogm_send(struct work_struct *work)
+       u16 tvlv_len = 0;
+       int ret;
+ 
+-      bat_v = container_of(work, struct batadv_priv_bat_v, ogm_wq.work);
+-      bat_priv = container_of(bat_v, struct batadv_priv, bat_v);
++      ASSERT_RTNL();
+ 
+       if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
+               goto out;
+@@ -235,6 +233,22 @@ out:
+       return;
+ }
+ 
++/**
++ * batadv_v_ogm_send() - periodic worker broadcasting the own OGM
++ * @work: work queue item
++ */
++static void batadv_v_ogm_send(struct work_struct *work)
++{
++      struct batadv_priv_bat_v *bat_v;
++      struct batadv_priv *bat_priv;
++
++      rtnl_lock();
++      bat_v = container_of(work, struct batadv_priv_bat_v, ogm_wq.work);
++      bat_priv = container_of(bat_v, struct batadv_priv, bat_v);
++      batadv_v_ogm_send_softif(bat_priv);
++      rtnl_unlock();
++}
++
+ /**
+  * batadv_v_ogm_iface_enable - prepare an interface for B.A.T.M.A.N. V
+  * @hard_iface: the interface to prepare
+@@ -261,6 +275,8 @@ void batadv_v_ogm_primary_iface_set(struct batadv_hard_iface *primary_iface)
+       struct batadv_priv *bat_priv = netdev_priv(primary_iface->soft_iface);
+       struct batadv_ogm2_packet *ogm_packet;
+ 
++      ASSERT_RTNL();
++
+       if (!bat_priv->bat_v.ogm_buff)
+               return;
+ 
+@@ -870,6 +886,8 @@ int batadv_v_ogm_init(struct batadv_priv *bat_priv)
+       unsigned char *ogm_buff;
+       u32 random_seqno;
+ 
++      ASSERT_RTNL();
++
+       bat_priv->bat_v.ogm_buff_len = BATADV_OGM2_HLEN;
+       ogm_buff = kzalloc(bat_priv->bat_v.ogm_buff_len, GFP_ATOMIC);
+       if (!ogm_buff)
+diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
+index 5c5762f0f89c8b79b52288104d975dc3753bbf82..11ced015ab639f0d82f12ae533a92f356734cafa 100644
+--- a/net/batman-adv/types.h
++++ b/net/batman-adv/types.h
+@@ -990,8 +990,8 @@ struct batadv_softif_vlan {
+ 
+ /**
+  * struct batadv_priv_bat_v - B.A.T.M.A.N. V per soft-interface private data
+- * @ogm_buff: buffer holding the OGM packet
+- * @ogm_buff_len: length of the OGM packet buffer
++ * @ogm_buff: buffer holding the OGM packet. rtnl protected
++ * @ogm_buff_len: length of the OGM packet buffer. rtnl protected
+  * @ogm_seqno: OGM sequence number - used to identify each OGM
+  * @ogm_wq: workqueue used to schedule OGM transmissions
+  */