[PATCH 4.4 75/85] batman-adv: bla: fix type misuse for backbone_gw hash indexing

From: Greg Kroah-Hartman
Date: Tue Sep 29 2020 - 07:06:20 EST


From: Linus Lüssing <ll@xxxxxxxxxxxxxxxxxx>

[ Upstream commit 097930e85f90f252c44dc0d084598265dd44ca48 ]

It seems that due to a copy & paste error the void pointer
in batadv_choose_backbone_gw() is cast to the wrong type.

Fixing this by using "struct batadv_bla_backbone_gw" instead of "struct
batadv_bla_claim" which better matches the caller's side.

For now it seems that we were lucky because the two structs both have
their orig/vid and addr/vid in the beginning. However I stumbled over
this issue when I was trying to add some debug variables in front of
"orig" in batadv_backbone_gw, which caused hash lookups to fail.

Fixes: 07568d0369f9 ("batman-adv: don't rely on positions in struct for hashing")
Signed-off-by: Linus Lüssing <ll@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Sven Eckelmann <sven@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/batman-adv/bridge_loop_avoidance.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c
index 9aa5daa551273..1267cbb1a329a 100644
--- a/net/batman-adv/bridge_loop_avoidance.c
+++ b/net/batman-adv/bridge_loop_avoidance.c
@@ -73,11 +73,12 @@ static inline u32 batadv_choose_claim(const void *data, u32 size)
/* return the index of the backbone gateway */
static inline u32 batadv_choose_backbone_gw(const void *data, u32 size)
{
- const struct batadv_bla_claim *claim = (struct batadv_bla_claim *)data;
+ const struct batadv_bla_backbone_gw *gw;
u32 hash = 0;

- hash = jhash(&claim->addr, sizeof(claim->addr), hash);
- hash = jhash(&claim->vid, sizeof(claim->vid), hash);
+ gw = (struct batadv_bla_backbone_gw *)data;
+ hash = jhash(&gw->orig, sizeof(gw->orig), hash);
+ hash = jhash(&gw->vid, sizeof(gw->vid), hash);

return hash % size;
}
--
2.25.1