diff options
| author | Sven Eckelmann <sven@narfation.org> | 2016-05-21 12:48:17 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-06-08 04:23:39 +0300 |
| commit | f38db9379af750cf0d6ecf957af129100dc62a9e (patch) | |
| tree | f1372fc2eb7f4b04db992e0d2f0b31ac8bdcc272 | |
| parent | 1c291d3adad88eb74a5d9a38a75266bfb527bfa2 (diff) | |
| download | linux-f38db9379af750cf0d6ecf957af129100dc62a9e.tar.xz | |
batman-adv: Fix double neigh_node_put in batadv_v_ogm_route_update
The router is put down twice when it was non-NULL and either orig_ifinfo is
NULL afterwards or batman-adv receives a packet with the same sequence
number. This will end up in a use-after-free when the batadv_neigh_node is
removed because the reference counter ended up too early at 0.
This patch is skipping netdev and is being sent directly to stable in
accordance with David S. Miller[1].
The reason is that this patch applies only on linux-4.6 and not on
linux-4.7/net because it was "accidentally" fixed by a refactoring
commit (more details in [2]).
It addresses a reference imbalance which systematically leads to a
use-after-free and then a kernel crash.
[1] https://www.mail-archive.com/b.a.t.m.a.n@lists.open-mesh.org/msg15258.html
[2] https://www.mail-archive.com/b.a.t.m.a.n@lists.open-mesh.org/msg15252.html
Fixes: 9323158ef9f4 ("batman-adv: OGMv2 - implement originators logic")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Antonio Quartulli <a@unstable.cc>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/batman-adv/bat_v_ogm.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/net/batman-adv/bat_v_ogm.c b/net/batman-adv/bat_v_ogm.c index d9bcbe6e7d65..91df28a100f9 100644 --- a/net/batman-adv/bat_v_ogm.c +++ b/net/batman-adv/bat_v_ogm.c @@ -529,8 +529,10 @@ static void batadv_v_ogm_route_update(struct batadv_priv *bat_priv, goto out; } - if (router) + if (router) { batadv_neigh_node_put(router); + router = NULL; + } /* Update routes, and check if the OGM is from the best next hop */ batadv_v_ogm_orig_update(bat_priv, orig_node, neigh_node, ogm2, |