commit a33d970d0b54b09746d5540af8271fad4eb10229 upstream.
The batadv_tt_local_entry was specific to a batadv_softif_vlan and held an implicit reference to it. But this reference was never stored in form of a pointer in the tt_local_entry itself. Instead batadv_tt_local_remove, batadv_tt_local_table_free and batadv_tt_local_purge_pending_clients depend on a consistent state of bat_priv->softif_vlan_list and that batadv_softif_vlan_get always returns the batadv_softif_vlan object which it has a reference for. But batadv_softif_vlan_get cannot guarantee that because it is working only with rcu_read_lock on this list. It can therefore happen that an vid is in this list twice or that batadv_softif_vlan_get cannot find the batadv_softif_vlan for an vid due to some other list operations taking place at the same time.
Instead add a batadv_softif_vlan pointer directly in batadv_tt_local_entry which will be used for the reference counter decremented on release of batadv_tt_local_entry.
Fixes: 35df3b298fc8 ("batman-adv: fix TT VLAN inconsistency on VLAN re-add") Signed-off-by: Sven Eckelmann sven@narfation.org Acked-by: Antonio Quartulli a@unstable.cc Signed-off-by: Marek Lindner mareklindner@neomailbox.ch Signed-off-by: Antonio Quartulli a@unstable.cc --- net/batman-adv/translation-table.c | 44 ++++-------------------------- net/batman-adv/types.h | 2 ++ 2 files changed, 7 insertions(+), 39 deletions(-)
diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index 117febee5fa6..4014e5130879 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -197,8 +197,11 @@ batadv_tt_global_hash_find(struct batadv_priv *bat_priv, const u8 *addr, static void batadv_tt_local_entry_free_ref(struct batadv_tt_local_entry *tt_local_entry) { - if (atomic_dec_and_test(&tt_local_entry->common.refcount)) + if (atomic_dec_and_test(&tt_local_entry->common.refcount)) { + batadv_softif_vlan_free_ref(tt_local_entry->vlan); + kfree_rcu(tt_local_entry, common.rcu); + } }
/** @@ -638,7 +641,6 @@ bool batadv_tt_local_add(struct net_device *soft_iface, const u8 *addr, if (unlikely(hash_added != 0)) { /* remove the reference for the hash */ batadv_tt_local_entry_free_ref(tt_local); - batadv_softif_vlan_free_ref(vlan); goto out; }
@@ -942,7 +944,6 @@ int batadv_tt_local_seq_print_text(struct seq_file *seq, void *offset) struct batadv_tt_common_entry *tt_common_entry; struct batadv_tt_local_entry *tt_local; struct batadv_hard_iface *primary_if; - struct batadv_softif_vlan *vlan; struct hlist_head *head; unsigned short vid; u32 i; @@ -979,13 +980,6 @@ int batadv_tt_local_seq_print_text(struct seq_file *seq, void *offset)
no_purge = tt_common_entry->flags & np_flag;
- vlan = batadv_softif_vlan_get(bat_priv, vid); - if (!vlan) { - seq_printf(seq, "Cannot retrieve VLAN %d\n", - BATADV_PRINT_VID(vid)); - continue; - } - seq_printf(seq, " * %pM %4i [%c%c%c%c%c%c] %3u.%03u (%#.8x)\n", tt_common_entry->addr, @@ -1003,9 +997,7 @@ int batadv_tt_local_seq_print_text(struct seq_file *seq, void *offset) BATADV_TT_CLIENT_ISOLA) ? 'I' : '.'), no_purge ? 0 : last_seen_secs, no_purge ? 0 : last_seen_msecs, - vlan->tt.crc); - - batadv_softif_vlan_free_ref(vlan); + tt_local->vlan->tt.crc); } rcu_read_unlock(); } @@ -1050,7 +1042,6 @@ u16 batadv_tt_local_remove(struct batadv_priv *bat_priv, const u8 *addr, { struct batadv_tt_local_entry *tt_local_entry; u16 flags, curr_flags = BATADV_NO_FLAGS; - struct batadv_softif_vlan *vlan; void *tt_entry_exists;
tt_local_entry = batadv_tt_local_hash_find(bat_priv, addr, vid); @@ -1090,14 +1081,6 @@ u16 batadv_tt_local_remove(struct batadv_priv *bat_priv, const u8 *addr, /* extra call to free the local tt entry */ batadv_tt_local_entry_free_ref(tt_local_entry);
- /* decrease the reference held for this vlan */ - vlan = batadv_softif_vlan_get(bat_priv, vid); - if (!vlan) - goto out; - - batadv_softif_vlan_free_ref(vlan); - batadv_softif_vlan_free_ref(vlan); - out: if (tt_local_entry) batadv_tt_local_entry_free_ref(tt_local_entry); @@ -1170,7 +1153,6 @@ static void batadv_tt_local_table_free(struct batadv_priv *bat_priv) spinlock_t *list_lock; /* protects write access to the hash lists */ struct batadv_tt_common_entry *tt_common_entry; struct batadv_tt_local_entry *tt_local; - struct batadv_softif_vlan *vlan; struct hlist_node *node_tmp; struct hlist_head *head; u32 i; @@ -1192,14 +1174,6 @@ static void batadv_tt_local_table_free(struct batadv_priv *bat_priv) struct batadv_tt_local_entry, common);
- /* decrease the reference held for this vlan */ - vlan = batadv_softif_vlan_get(bat_priv, - tt_common_entry->vid); - if (vlan) { - batadv_softif_vlan_free_ref(vlan); - batadv_softif_vlan_free_ref(vlan); - } - batadv_tt_local_entry_free_ref(tt_local); } spin_unlock_bh(list_lock); @@ -3229,7 +3203,6 @@ static void batadv_tt_local_purge_pending_clients(struct batadv_priv *bat_priv) struct batadv_hashtable *hash = bat_priv->tt.local_hash; struct batadv_tt_common_entry *tt_common; struct batadv_tt_local_entry *tt_local; - struct batadv_softif_vlan *vlan; struct hlist_node *node_tmp; struct hlist_head *head; spinlock_t *list_lock; /* protects write access to the hash lists */ @@ -3259,13 +3232,6 @@ static void batadv_tt_local_purge_pending_clients(struct batadv_priv *bat_priv) struct batadv_tt_local_entry, common);
- /* decrease the reference held for this vlan */ - vlan = batadv_softif_vlan_get(bat_priv, tt_common->vid); - if (vlan) { - batadv_softif_vlan_free_ref(vlan); - batadv_softif_vlan_free_ref(vlan); - } - batadv_tt_local_entry_free_ref(tt_local); } spin_unlock_bh(list_lock); diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index cbd347c2e4a5..dcf285fae2e6 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -947,10 +947,12 @@ struct batadv_tt_common_entry { * struct batadv_tt_local_entry - translation table local entry data * @common: general translation table data * @last_seen: timestamp used for purging stale tt local entries + * @vlan: soft-interface vlan of the entry */ struct batadv_tt_local_entry { struct batadv_tt_common_entry common; unsigned long last_seen; + struct batadv_softif_vlan *vlan; };
/**