batman-adv: Make bat_priv->curr_gw an rcu protected pointer
The rcu protected macros rcu_dereference() and rcu_assign_pointer() for the bat_priv->curr_gw need to be used, as well as spin/rcu locking. Otherwise we might end up using a curr_gw pointer pointing to already freed memory. Reported-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Linus Lüssing <linus.luessing@ascom.ch> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
This commit is contained in:
Linus Lüssing
Marek Lindner
Родитель
f3e0008f01
Коммит
5d02b3cdfa
|
|
@ -44,19 +44,29 @@ static void gw_node_free_ref(struct gw_node *gw_node)
|
|||
|
||||
void *gw_get_selected(struct bat_priv *bat_priv)
|
||||
{
|
||||
struct gw_node *curr_gateway_tmp = bat_priv->curr_gw;
|
||||
struct gw_node *curr_gateway_tmp;
|
||||
struct orig_node *orig_node = NULL;
|
||||
|
||||
rcu_read_lock();
|
||||
curr_gateway_tmp = rcu_dereference(bat_priv->curr_gw);
|
||||
if (!curr_gateway_tmp)
|
||||
return NULL;
|
||||
goto out;
|
||||
|
||||
return curr_gateway_tmp->orig_node;
|
||||
orig_node = curr_gateway_tmp->orig_node;
|
||||
|
||||
out:
|
||||
rcu_read_unlock();
|
||||
return orig_node;
|
||||
}
|
||||
|
||||
void gw_deselect(struct bat_priv *bat_priv)
|
||||
{
|
||||
struct gw_node *gw_node = bat_priv->curr_gw;
|
||||
struct gw_node *gw_node;
|
||||
|
||||
bat_priv->curr_gw = NULL;
|
||||
spin_lock_bh(&bat_priv->gw_list_lock);
|
||||
gw_node = rcu_dereference(bat_priv->curr_gw);
|
||||
rcu_assign_pointer(bat_priv->curr_gw, NULL);
|
||||
spin_unlock_bh(&bat_priv->gw_list_lock);
|
||||
|
||||
if (gw_node)
|
||||
gw_node_free_ref(gw_node);
|
||||
|
|
@ -64,12 +74,15 @@ void gw_deselect(struct bat_priv *bat_priv)
|
|||
|
||||
static void gw_select(struct bat_priv *bat_priv, struct gw_node *new_gw_node)
|
||||
{
|
||||
struct gw_node *curr_gw_node = bat_priv->curr_gw;
|
||||
struct gw_node *curr_gw_node;
|
||||
|
||||
if (new_gw_node && !atomic_inc_not_zero(&new_gw_node->refcount))
|
||||
new_gw_node = NULL;
|
||||
|
||||
bat_priv->curr_gw = new_gw_node;
|
||||
spin_lock_bh(&bat_priv->gw_list_lock);
|
||||
curr_gw_node = rcu_dereference(bat_priv->curr_gw);
|
||||
rcu_assign_pointer(bat_priv->curr_gw, new_gw_node);
|
||||
spin_unlock_bh(&bat_priv->gw_list_lock);
|
||||
|
||||
if (curr_gw_node)
|
||||
gw_node_free_ref(curr_gw_node);
|
||||
|
|
@ -78,7 +91,7 @@ static void gw_select(struct bat_priv *bat_priv, struct gw_node *new_gw_node)
|
|||
void gw_election(struct bat_priv *bat_priv)
|
||||
{
|
||||
struct hlist_node *node;
|
||||
struct gw_node *gw_node, *curr_gw_tmp = NULL;
|
||||
struct gw_node *gw_node, *curr_gw, *curr_gw_tmp = NULL;
|
||||
uint8_t max_tq = 0;
|
||||
uint32_t max_gw_factor = 0, tmp_gw_factor = 0;
|
||||
int down, up;
|
||||
|
|
@ -92,19 +105,23 @@ void gw_election(struct bat_priv *bat_priv)
|
|||
if (atomic_read(&bat_priv->gw_mode) != GW_MODE_CLIENT)
|
||||
return;
|
||||
|
||||
if (bat_priv->curr_gw)
|
||||
return;
|
||||
|
||||
rcu_read_lock();
|
||||
if (hlist_empty(&bat_priv->gw_list)) {
|
||||
curr_gw = rcu_dereference(bat_priv->curr_gw);
|
||||
if (curr_gw) {
|
||||
rcu_read_unlock();
|
||||
return;
|
||||
}
|
||||
|
||||
if (bat_priv->curr_gw) {
|
||||
if (hlist_empty(&bat_priv->gw_list)) {
|
||||
|
||||
if (curr_gw) {
|
||||
rcu_read_unlock();
|
||||
bat_dbg(DBG_BATMAN, bat_priv,
|
||||
"Removing selected gateway - "
|
||||
"no gateway in range\n");
|
||||
gw_deselect(bat_priv);
|
||||
}
|
||||
} else
|
||||
rcu_read_unlock();
|
||||
|
||||
return;
|
||||
}
|
||||
|
|
@ -153,12 +170,12 @@ void gw_election(struct bat_priv *bat_priv)
|
|||
max_gw_factor = tmp_gw_factor;
|
||||
}
|
||||
|
||||
if (bat_priv->curr_gw != curr_gw_tmp) {
|
||||
if ((bat_priv->curr_gw) && (!curr_gw_tmp))
|
||||
if (curr_gw != curr_gw_tmp) {
|
||||
if ((curr_gw) && (!curr_gw_tmp))
|
||||
bat_dbg(DBG_BATMAN, bat_priv,
|
||||
"Removing selected gateway - "
|
||||
"no gateway in range\n");
|
||||
else if ((!bat_priv->curr_gw) && (curr_gw_tmp))
|
||||
else if ((!curr_gw) && (curr_gw_tmp))
|
||||
bat_dbg(DBG_BATMAN, bat_priv,
|
||||
"Adding route to gateway %pM "
|
||||
"(gw_flags: %i, tq: %i)\n",
|
||||
|
|
@ -181,31 +198,35 @@ void gw_election(struct bat_priv *bat_priv)
|
|||
|
||||
void gw_check_election(struct bat_priv *bat_priv, struct orig_node *orig_node)
|
||||
{
|
||||
struct gw_node *curr_gateway_tmp = bat_priv->curr_gw;
|
||||
struct gw_node *curr_gateway_tmp;
|
||||
uint8_t gw_tq_avg, orig_tq_avg;
|
||||
|
||||
rcu_read_lock();
|
||||
curr_gateway_tmp = rcu_dereference(bat_priv->curr_gw);
|
||||
if (!curr_gateway_tmp)
|
||||
return;
|
||||
goto out_rcu;
|
||||
|
||||
if (!curr_gateway_tmp->orig_node)
|
||||
goto deselect;
|
||||
goto deselect_rcu;
|
||||
|
||||
if (!curr_gateway_tmp->orig_node->router)
|
||||
goto deselect;
|
||||
goto deselect_rcu;
|
||||
|
||||
/* this node already is the gateway */
|
||||
if (curr_gateway_tmp->orig_node == orig_node)
|
||||
return;
|
||||
goto out_rcu;
|
||||
|
||||
if (!orig_node->router)
|
||||
return;
|
||||
goto out_rcu;
|
||||
|
||||
gw_tq_avg = curr_gateway_tmp->orig_node->router->tq_avg;
|
||||
rcu_read_unlock();
|
||||
|
||||
orig_tq_avg = orig_node->router->tq_avg;
|
||||
|
||||
/* the TQ value has to be better */
|
||||
if (orig_tq_avg < gw_tq_avg)
|
||||
return;
|
||||
goto out;
|
||||
|
||||
/**
|
||||
* if the routing class is greater than 3 the value tells us how much
|
||||
|
|
@ -213,15 +234,23 @@ void gw_check_election(struct bat_priv *bat_priv, struct orig_node *orig_node)
|
|||
**/
|
||||
if ((atomic_read(&bat_priv->gw_sel_class) > 3) &&
|
||||
(orig_tq_avg - gw_tq_avg < atomic_read(&bat_priv->gw_sel_class)))
|
||||
return;
|
||||
goto out;
|
||||
|
||||
bat_dbg(DBG_BATMAN, bat_priv,
|
||||
"Restarting gateway selection: better gateway found (tq curr: "
|
||||
"%i, tq new: %i)\n",
|
||||
gw_tq_avg, orig_tq_avg);
|
||||
goto deselect;
|
||||
|
||||
out_rcu:
|
||||
rcu_read_unlock();
|
||||
goto out;
|
||||
deselect_rcu:
|
||||
rcu_read_unlock();
|
||||
deselect:
|
||||
gw_deselect(bat_priv);
|
||||
out:
|
||||
return;
|
||||
}
|
||||
|
||||
static void gw_node_add(struct bat_priv *bat_priv,
|
||||
|
|
@ -278,7 +307,7 @@ void gw_node_update(struct bat_priv *bat_priv,
|
|||
"Gateway %pM removed from gateway list\n",
|
||||
orig_node->orig);
|
||||
|
||||
if (gw_node == bat_priv->curr_gw) {
|
||||
if (gw_node == rcu_dereference(bat_priv->curr_gw)) {
|
||||
rcu_read_unlock();
|
||||
gw_deselect(bat_priv);
|
||||
return;
|
||||
|
|
@ -316,7 +345,7 @@ void gw_node_purge(struct bat_priv *bat_priv)
|
|||
atomic_read(&bat_priv->mesh_state) == MESH_ACTIVE)
|
||||
continue;
|
||||
|
||||
if (bat_priv->curr_gw == gw_node)
|
||||
if (rcu_dereference(bat_priv->curr_gw) == gw_node)
|
||||
gw_deselect(bat_priv);
|
||||
|
||||
hlist_del_rcu(&gw_node->list);
|
||||
|
|
@ -330,12 +359,16 @@ void gw_node_purge(struct bat_priv *bat_priv)
|
|||
static int _write_buffer_text(struct bat_priv *bat_priv,
|
||||
struct seq_file *seq, struct gw_node *gw_node)
|
||||
{
|
||||
int down, up;
|
||||
struct gw_node *curr_gw;
|
||||
int down, up, ret;
|
||||
|
||||
gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags, &down, &up);
|
||||
|
||||
return seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %3i - %i%s/%i%s\n",
|
||||
(bat_priv->curr_gw == gw_node ? "=>" : " "),
|
||||
rcu_read_lock();
|
||||
curr_gw = rcu_dereference(bat_priv->curr_gw);
|
||||
|
||||
ret = seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %3i - %i%s/%i%s\n",
|
||||
(curr_gw == gw_node ? "=>" : " "),
|
||||
gw_node->orig_node->orig,
|
||||
gw_node->orig_node->router->tq_avg,
|
||||
gw_node->orig_node->router->addr,
|
||||
|
|
@ -345,6 +378,9 @@ static int _write_buffer_text(struct bat_priv *bat_priv,
|
|||
(down > 2048 ? "MBit" : "KBit"),
|
||||
(up > 2048 ? up / 1024 : up),
|
||||
(up > 2048 ? "MBit" : "KBit"));
|
||||
|
||||
rcu_read_unlock();
|
||||
return ret;
|
||||
}
|
||||
|
||||
int gw_client_seq_print_text(struct seq_file *seq, void *offset)
|
||||
|
|
@ -465,8 +501,12 @@ int gw_is_target(struct bat_priv *bat_priv, struct sk_buff *skb)
|
|||
if (atomic_read(&bat_priv->gw_mode) == GW_MODE_SERVER)
|
||||
return -1;
|
||||
|
||||
if (!bat_priv->curr_gw)
|
||||
rcu_read_lock();
|
||||
if (!rcu_dereference(bat_priv->curr_gw)) {
|
||||
rcu_read_unlock();
|
||||
return 0;
|
||||
}
|
||||
rcu_read_unlock();
|
||||
|
||||
return 1;
|
||||
}
|
||||
|
|
|
|||
|
|
@ -162,7 +162,7 @@ struct bat_priv {
|
|||
spinlock_t forw_bcast_list_lock; /* protects */
|
||||
spinlock_t hna_lhash_lock; /* protects hna_local_hash */
|
||||
spinlock_t hna_ghash_lock; /* protects hna_global_hash */
|
||||
spinlock_t gw_list_lock; /* protects gw_list */
|
||||
spinlock_t gw_list_lock; /* protects gw_list and curr_gw */
|
||||
spinlock_t vis_hash_lock; /* protects vis_hash */
|
||||
spinlock_t vis_list_lock; /* protects vis_info::recv_list */
|
||||
spinlock_t softif_neigh_lock; /* protects soft-interface neigh list */
|
||||
|
|
@ -171,7 +171,7 @@ struct bat_priv {
|
|||
struct delayed_work hna_work;
|
||||
struct delayed_work orig_work;
|
||||
struct delayed_work vis_work;
|
||||
struct gw_node *curr_gw;
|
||||
struct gw_node __rcu *curr_gw; /* rcu protected pointer */
|
||||
struct vis_info *my_vis_info;
|
||||
};
|
||||
|
||||
|
|
|
|||
Загрузка…
Ссылка в новой задаче