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authorSven Eckelmann <sven@narfation.org>2017-12-26 17:14:01 +0300
committerSimon Wunderlich <sw@simonwunderlich.de>2018-02-25 22:19:34 +0300
commitf22e08932c2960f29b5e828e745c9f3fb7c1bb86 (patch)
treed4c971d4feef6c4553cb659cada3cab0b159ed17 /net/batman-adv/hard-interface.c
parentfce672db548ff19e76a08a32a829544617229bc2 (diff)
downloadlinux-f22e08932c2960f29b5e828e745c9f3fb7c1bb86.tar.xz
batman-adv: Fix internal interface indices types
batman-adv uses internal indices for each enabled and active interface. It is currently used by the B.A.T.M.A.N. IV algorithm to identifify the correct position in the ogm_cnt bitmaps. The type for the number of enabled interfaces (which defines the next interface index) was set to char. This type can be (depending on the architecture) either signed (limiting batman-adv to 127 active slave interfaces) or unsigned (limiting batman-adv to 255 active slave interfaces). This limit was not correctly checked when an interface was enabled and thus an overflow happened. This was only catched on systems with the signed char type when the B.A.T.M.A.N. IV code tried to resize its counter arrays with a negative size. The if_num interface index was only a s16 and therefore significantly smaller than the ifindex (int) used by the code net code. Both &batadv_hard_iface->if_num and &batadv_priv->num_ifaces must be (unsigned) int to support the same number of slave interfaces as the net core code. And the interface activation code must check the number of active slave interfaces to avoid integer overflows. Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol") Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Diffstat (limited to 'net/batman-adv/hard-interface.c')
-rw-r--r--net/batman-adv/hard-interface.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
index 5f186bff284a..68b54a39c51d 100644
--- a/net/batman-adv/hard-interface.c
+++ b/net/batman-adv/hard-interface.c
@@ -763,6 +763,11 @@ int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
hard_iface->soft_iface = soft_iface;
bat_priv = netdev_priv(hard_iface->soft_iface);
+ if (bat_priv->num_ifaces >= UINT_MAX) {
+ ret = -ENOSPC;
+ goto err_dev;
+ }
+
ret = netdev_master_upper_dev_link(hard_iface->net_dev,
soft_iface, NULL, NULL, NULL);
if (ret)
@@ -876,7 +881,7 @@ void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface);
/* nobody uses this interface anymore */
- if (!bat_priv->num_ifaces) {
+ if (bat_priv->num_ifaces == 0) {
batadv_gw_check_client_stop(bat_priv);
if (autodel == BATADV_IF_CLEANUP_AUTO)
@@ -912,7 +917,7 @@ batadv_hardif_add_interface(struct net_device *net_dev)
if (ret)
goto free_if;
- hard_iface->if_num = -1;
+ hard_iface->if_num = 0;
hard_iface->net_dev = net_dev;
hard_iface->soft_iface = NULL;
hard_iface->if_status = BATADV_IF_NOT_IN_USE;