diff options
| author | Linus Lüssing <linus.luessing@c0d3.blue> | 2019-04-24 03:19:14 +0200 |
|---|---|---|
| committer | Simon Wunderlich <sw@simonwunderlich.de> | 2019-05-06 11:40:46 +0200 |
| commit | a3c7cd0cdf1107f891aff847ad481e34df727055 (patch) | |
| tree | 7e22ab7d0e0ec6a22b1095bd2af1b61bf79ad9a2 /net | |
| parent | bdc76fd299600736e832f1525f4f23dd210b97cb (diff) | |
batman-adv: mcast: fix multicast tt/tvlv worker locking
Syzbot has reported some issues with the locking assumptions made for
the multicast tt/tvlv worker: It was able to trigger the WARN_ON() in
batadv_mcast_mla_tt_retract() and batadv_mcast_mla_tt_add().
While hard/not reproduceable for us so far it seems that the
delayed_work_pending() we use might not be quite safe from reordering.
Therefore this patch adds an explicit, new spinlock to protect the
update of the mla_list and flags in bat_priv and then removes the
WARN_ON(delayed_work_pending()).
Reported-by: syzbot+83f2d54ec6b7e417e13f@syzkaller.appspotmail.com
Reported-by: syzbot+050927a651272b145a5d@syzkaller.appspotmail.com
Reported-by: syzbot+979ffc89b87309b1b94b@syzkaller.appspotmail.com
Reported-by: syzbot+f9f3f388440283da2965@syzkaller.appspotmail.com
Fixes: cbebd363b2e9 ("batman-adv: Use own timer for multicast TT and TVLV updates")
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Diffstat (limited to 'net')
| -rw-r--r-- | net/batman-adv/main.c | 1 | ||||
| -rw-r--r-- | net/batman-adv/multicast.c | 11 | ||||
| -rw-r--r-- | net/batman-adv/types.h | 5 |
3 files changed, 9 insertions, 8 deletions
diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c index 75750870cf04..f8725786b596 100644 --- a/net/batman-adv/main.c +++ b/net/batman-adv/main.c @@ -161,6 +161,7 @@ int batadv_mesh_init(struct net_device *soft_iface) spin_lock_init(&bat_priv->tt.commit_lock); spin_lock_init(&bat_priv->gw.list_lock); #ifdef CONFIG_BATMAN_ADV_MCAST + spin_lock_init(&bat_priv->mcast.mla_lock); spin_lock_init(&bat_priv->mcast.want_lists_lock); #endif spin_lock_init(&bat_priv->tvlv.container_list_lock); diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c index f91b1b6265cf..1b985ab89c08 100644 --- a/net/batman-adv/multicast.c +++ b/net/batman-adv/multicast.c @@ -325,8 +325,6 @@ static void batadv_mcast_mla_list_free(struct hlist_head *mcast_list) * translation table except the ones listed in the given mcast_list. * * If mcast_list is NULL then all are retracted. - * - * Do not call outside of the mcast worker! (or cancel mcast worker first) */ static void batadv_mcast_mla_tt_retract(struct batadv_priv *bat_priv, struct hlist_head *mcast_list) @@ -334,8 +332,6 @@ static void batadv_mcast_mla_tt_retract(struct batadv_priv *bat_priv, struct batadv_hw_addr *mcast_entry; struct hlist_node *tmp; - WARN_ON(delayed_work_pending(&bat_priv->mcast.work)); - hlist_for_each_entry_safe(mcast_entry, tmp, &bat_priv->mcast.mla_list, list) { if (mcast_list && @@ -359,8 +355,6 @@ static void batadv_mcast_mla_tt_retract(struct batadv_priv *bat_priv, * * Adds multicast listener announcements from the given mcast_list to the * translation table if they have not been added yet. - * - * Do not call outside of the mcast worker! (or cancel mcast worker first) */ static void batadv_mcast_mla_tt_add(struct batadv_priv *bat_priv, struct hlist_head *mcast_list) @@ -368,8 +362,6 @@ static void batadv_mcast_mla_tt_add(struct batadv_priv *bat_priv, struct batadv_hw_addr *mcast_entry; struct hlist_node *tmp; - WARN_ON(delayed_work_pending(&bat_priv->mcast.work)); - if (!mcast_list) return; @@ -658,7 +650,10 @@ static void batadv_mcast_mla_update(struct work_struct *work) priv_mcast = container_of(delayed_work, struct batadv_priv_mcast, work); bat_priv = container_of(priv_mcast, struct batadv_priv, mcast); + spin_lock(&bat_priv->mcast.mla_lock); __batadv_mcast_mla_update(bat_priv); + spin_unlock(&bat_priv->mcast.mla_lock); + batadv_mcast_start_timer(bat_priv); } diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index a21b34ed6548..ed0f6a519de5 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -1224,6 +1224,11 @@ struct batadv_priv_mcast { unsigned char bridged:1; /** + * @mla_lock: a lock protecting mla_list and mla_flags + */ + spinlock_t mla_lock; + + /** * @num_want_all_unsnoopables: number of nodes wanting unsnoopable IP * traffic */ |