Eric Lee / smarc-fsl-linux-kernel

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Commit 377fe0f968b30a1a714fab53a908061914f30e26

Authored by Antonio Quartulli
Committed by Antonio Quartulli
1 parent be181015a1

batman-adv: increase orig refcount when storing ref in gw_node 

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>

Showing 1 changed file with 9 additions and 2 deletions Side-by-side Diff

net/batman-adv/gateway_client.c
Diff comments   View file @ 377fe0f
... ... @@ -42,8 +42,10 @@
42 42  
43 43 static void batadv_gw_node_free_ref(struct batadv_gw_node *gw_node)
44 44 {
45   - if (atomic_dec_and_test(&gw_node->refcount))
  45 + if (atomic_dec_and_test(&gw_node->refcount)) {
  46 + batadv_orig_node_free_ref(gw_node->orig_node);
46 47 kfree_rcu(gw_node, rcu);
  48 + }
47 49 }
48 50  
49 51 static struct batadv_gw_node *
50 52  
51 53  
... ... @@ -406,9 +408,14 @@
406 408 if (gateway->bandwidth_down == 0)
407 409 return;
408 410  
  411 + if (!atomic_inc_not_zero(&orig_node->refcount))
  412 + return;
  413 +
409 414 gw_node = kzalloc(sizeof(*gw_node), GFP_ATOMIC);
410   - if (!gw_node)
  415 + if (!gw_node) {
  416 + batadv_orig_node_free_ref(orig_node);
411 417 return;
  418 + }
412 419  
413 420 INIT_HLIST_NODE(&gw_node->list);
414 421 gw_node->orig_node = orig_node;