56 lines
2.1 KiB
Diff
56 lines
2.1 KiB
Diff
From: Sven Eckelmann <sven@narfation.org>
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Date: Thu, 6 Sep 2018 14:35:28 +0200
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Subject: batman-adv: Prevent duplicated tvlv handler
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The function batadv_tvlv_handler_register is responsible for adding new
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tvlv_handler to the handler_list. It first checks whether the entry
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already is in the list or not. If it is, then the creation of a new entry
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is aborted.
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But the lock for the list is only held when the list is really modified.
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This could lead to duplicated entries because another context could create
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an entry with the same key between the check and the list manipulation.
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The check and the manipulation of the list must therefore be in the same
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locked code section.
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Fixes: 0b6aa0d43767 ("batman-adv: tvlv - basic infrastructure")
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Signed-off-by: Sven Eckelmann <sven@narfation.org>
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Acked-by: Marek Lindner <mareklindner@neomailbox.ch>
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Origin: upstream, https://git.open-mesh.org/batman-adv.git/commit/acabad79e01740525cf4ff8ce6e9a210b683d420
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diff --git a/net/batman-adv/tvlv.c b/net/batman-adv/tvlv.c
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index a637458205d16bf838f796383d8cc15ac861801b..40e69c9346d22c09481544b8b4dec56cad88b64a 100644
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--- a/net/batman-adv/tvlv.c
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+++ b/net/batman-adv/tvlv.c
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@@ -529,15 +529,20 @@ void batadv_tvlv_handler_register(struct batadv_priv *bat_priv,
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{
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struct batadv_tvlv_handler *tvlv_handler;
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+ spin_lock_bh(&bat_priv->tvlv.handler_list_lock);
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+
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tvlv_handler = batadv_tvlv_handler_get(bat_priv, type, version);
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if (tvlv_handler) {
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+ spin_unlock_bh(&bat_priv->tvlv.handler_list_lock);
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batadv_tvlv_handler_put(tvlv_handler);
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return;
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}
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tvlv_handler = kzalloc(sizeof(*tvlv_handler), GFP_ATOMIC);
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- if (!tvlv_handler)
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+ if (!tvlv_handler) {
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+ spin_unlock_bh(&bat_priv->tvlv.handler_list_lock);
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return;
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+ }
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tvlv_handler->ogm_handler = optr;
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tvlv_handler->unicast_handler = uptr;
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@@ -547,7 +552,6 @@ void batadv_tvlv_handler_register(struct batadv_priv *bat_priv,
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kref_init(&tvlv_handler->refcount);
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INIT_HLIST_NODE(&tvlv_handler->list);
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- spin_lock_bh(&bat_priv->tvlv.handler_list_lock);
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kref_get(&tvlv_handler->refcount);
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hlist_add_head_rcu(&tvlv_handler->list, &bat_priv->tvlv.handler_list);
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spin_unlock_bh(&bat_priv->tvlv.handler_list_lock);
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