The following commit has been merged in the master branch: commit 816cd5b83e4d8f3c8106966e64a025408caee3f6 Author: Pau Koning paukoning@gmail.com Date: Tue Feb 12 00:18:45 2013 +0000
batman-adv: Fix NULL pointer dereference in DAT hash collision avoidance
An entry in DAT with the hashed position of 0 can cause a NULL pointer dereference when the first entry is checked by batadv_choose_next_candidate. This first candidate automatically has the max value of 0 and the max_orig_node of NULL. Not checking max_orig_node for NULL in batadv_is_orig_node_eligible will lead to a NULL pointer dereference when checking for the lowest address.
This problem was added in 785ea1144182c341b8b85b0f8180291839d176a8 ("batman-adv: Distributed ARP Table - create DHT helper functions").
Signed-off-by: Pau Koning paukoning@gmail.com Signed-off-by: David S. Miller davem@davemloft.net
diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c index 183f97a..5539215 100644 --- a/net/batman-adv/distributed-arp-table.c +++ b/net/batman-adv/distributed-arp-table.c @@ -440,7 +440,7 @@ static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res, /* this is an hash collision with the temporary selected node. Choose * the one with the lowest address */ - if ((tmp_max == max) && + if ((tmp_max == max) && max_orig_node && (batadv_compare_eth(candidate->orig, max_orig_node->orig) > 0)) goto out;