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authorSven Eckelmann <sven@narfation.org>2019-07-07 23:04:57 +0200
committerSimon Wunderlich <sw@simonwunderlich.de>2019-07-22 21:34:58 +0200
commitf7af86ccf1882084293b11077deec049fd01da63 (patch)
tree522b67465b1aa16d4ec47c44d0004430efa7bf60
parentbatman-adv: Fix netlink dumping of all mcast_flags buckets (diff)
downloadlinux-dev-f7af86ccf1882084293b11077deec049fd01da63.tar.xz
linux-dev-f7af86ccf1882084293b11077deec049fd01da63.zip
batman-adv: Fix deletion of RTR(4|6) mcast list entries
The multicast code uses the lists bat_priv->mcast.want_all_rtr*_list to store all all originator nodes which don't have the flag no-RTR4 or no-RTR6 set. When an originator is purged, it has to be removed from these lists. Since all entries without the BATADV_MCAST_WANT_NO_RTR4/6 are stored in these lists, they have to be handled like entries which have these flags set to force the update routines to remove them from the lists when purging the originator. Not doing so will leave a pointer to a freed memory region inside the list. Trying to operate on these lists will then cause an use-after-free error: BUG: KASAN: use-after-free in batadv_mcast_want_rtr4_update+0x335/0x3a0 [batman_adv] Write of size 8 at addr ffff888007b41a38 by task swapper/0/0 Fixes: 61caf3d109f5 ("batman-adv: mcast: detect, distribute and maintain multicast router presence") Signed-off-by: Sven Eckelmann <sven@narfation.org> Acked-by: Linus Lüssing <linus.luessing@c0d3.blue> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
-rw-r--r--net/batman-adv/multicast.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c
index a3488cfb3d1e..1d5bdf3a4b65 100644
--- a/net/batman-adv/multicast.c
+++ b/net/batman-adv/multicast.c
@@ -2420,8 +2420,10 @@ void batadv_mcast_purge_orig(struct batadv_orig_node *orig)
batadv_mcast_want_unsnoop_update(bat_priv, orig, BATADV_NO_FLAGS);
batadv_mcast_want_ipv4_update(bat_priv, orig, BATADV_NO_FLAGS);
batadv_mcast_want_ipv6_update(bat_priv, orig, BATADV_NO_FLAGS);
- batadv_mcast_want_rtr4_update(bat_priv, orig, BATADV_NO_FLAGS);
- batadv_mcast_want_rtr6_update(bat_priv, orig, BATADV_NO_FLAGS);
+ batadv_mcast_want_rtr4_update(bat_priv, orig,
+ BATADV_MCAST_WANT_NO_RTR4);
+ batadv_mcast_want_rtr6_update(bat_priv, orig,
+ BATADV_MCAST_WANT_NO_RTR6);
spin_unlock_bh(&orig->mcast_handler_lock);
}