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author | Sven Eckelmann <sven@narfation.org> | 2016-03-11 16:44:06 +0100 |
---|---|---|
committer | Antonio Quartulli <a@unstable.cc> | 2016-04-29 19:46:11 +0800 |
commit | abe59c65225ccd63a5964e2f2a73dd2995b948e7 (patch) | |
tree | c4d0400fc0300e70782296e1ac8375a98625d2ac /net/batman-adv/types.h | |
parent | a33d970d0b54b09746d5540af8271fad4eb10229 (diff) | |
download | linux-abe59c65225ccd63a5964e2f2a73dd2995b948e7.tar.bz2 |
batman-adv: Fix reference counting of hardif_neigh_node object for neigh_node
The batadv_neigh_node was specific to a batadv_hardif_neigh_node and held
an implicit reference to it. But this reference was never stored in form of
a pointer in the batadv_neigh_node itself. Instead
batadv_neigh_node_release depends on a consistent state of
hard_iface->neigh_list and that batadv_hardif_neigh_get always returns the
batadv_hardif_neigh_node object which it has a reference for. But
batadv_hardif_neigh_get cannot guarantee that because it is working only
with rcu_read_lock on this list. It can therefore happen that a neigh_addr
is in this list twice or that batadv_hardif_neigh_get cannot find the
batadv_hardif_neigh_node for an neigh_addr due to some other list
operations taking place at the same time.
Instead add a batadv_hardif_neigh_node pointer directly in
batadv_neigh_node which will be used for the reference counter decremented
on release of batadv_neigh_node.
Fixes: cef63419f7db ("batman-adv: add list of unique single hop neighbors per hard-interface")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a@unstable.cc>
Diffstat (limited to 'net/batman-adv/types.h')
-rw-r--r-- | net/batman-adv/types.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index 65afd090ab3e..1e47fbe8bb7b 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -433,6 +433,7 @@ struct batadv_hardif_neigh_node { * @ifinfo_lock: lock protecting private ifinfo members and list * @if_incoming: pointer to incoming hard-interface * @last_seen: when last packet via this neighbor was received + * @hardif_neigh: hardif_neigh of this neighbor * @refcount: number of contexts the object is used * @rcu: struct used for freeing in an RCU-safe manner */ @@ -444,6 +445,7 @@ struct batadv_neigh_node { spinlock_t ifinfo_lock; /* protects ifinfo_list and its members */ struct batadv_hard_iface *if_incoming; unsigned long last_seen; + struct batadv_hardif_neigh_node *hardif_neigh; struct kref refcount; struct rcu_head rcu; }; |