| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.14 134/140] batman-adv: increase orig refcount when storing ref in gw_node | Date | Wed, 28 May 2014 21:34:33 -0700 |
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3.14-stable review patch. If anyone has any objections, please let me know.
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From: Antonio Quartulli <antonio@open-mesh.com>
[ Upstream commit 377fe0f968b30a1a714fab53a908061914f30e26 ]
A pointer to the orig_node representing a bat-gateway is stored in the gw_node->orig_node member, but the refcount for such orig_node is never increased. This leads to memory faults when gw_node->orig_node is accessed and the originator has already been freed.
Fix this by increasing the refcount on gw_node creation and decreasing it on gw_node free.
Signed-off-by: Antonio Quartulli <antonio@open-mesh.com> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/batman-adv/gateway_client.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
--- a/net/batman-adv/gateway_client.c +++ b/net/batman-adv/gateway_client.c @@ -42,8 +42,10 @@ static void batadv_gw_node_free_ref(struct batadv_gw_node *gw_node) { - if (atomic_dec_and_test(&gw_node->refcount)) + if (atomic_dec_and_test(&gw_node->refcount)) { + batadv_orig_node_free_ref(gw_node->orig_node); kfree_rcu(gw_node, rcu); + } } static struct batadv_gw_node * @@ -408,9 +410,14 @@ static void batadv_gw_node_add(struct ba if (gateway->bandwidth_down == 0) return; + if (!atomic_inc_not_zero(&orig_node->refcount)) + return; + gw_node = kzalloc(sizeof(*gw_node), GFP_ATOMIC); - if (!gw_node) + if (!gw_node) { + batadv_orig_node_free_ref(orig_node); return; + } INIT_HLIST_NODE(&gw_node->list); gw_node->orig_node = orig_node;
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