[PATCH 5.4 021/111] batman-adv: initialize "struct batadv_tvlv_tt_vlan_data"->reserved field

[Greg Kroah-Hartman]

From: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>

commit 08c27f3322fec11950b8f1384aa0f3b11d028528 upstream.

KMSAN found uninitialized value at batadv_tt_prepare_tvlv_local_data()
[1], for commit ced72933a5e8ab52 ("batman-adv: use CRC32C instead of CRC16
in TT code") inserted 'reserved' field into "struct batadv_tvlv_tt_data"
and commit 7ea7b4a142758dea ("batman-adv: make the TT CRC logic VLAN
specific") moved that field to "struct batadv_tvlv_tt_vlan_data" but left
that field uninitialized.

[1] https://syzkaller.appspot.com/bug?id=07f3e6dba96f0eb3cabab986adcd8a58b9bdbe9d

Reported-by: syzbot <syzbot+50ee810676e6a089487b@xxxxxxxxxxxxxxxxxxxxxxxxx>
Tested-by: syzbot <syzbot+50ee810676e6a089487b@xxxxxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Fixes: ced72933a5e8ab52 ("batman-adv: use CRC32C instead of CRC16 in TT code")
Fixes: 7ea7b4a142758dea ("batman-adv: make the TT CRC logic VLAN specific")
Acked-by: Sven Eckelmann <sven@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 net/batman-adv/translation-table.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -891,6 +891,7 @@ batadv_tt_prepare_tvlv_global_data(struc
 	hlist_for_each_entry_rcu(vlan, &orig_node->vlan_list, list) {
 		tt_vlan->vid = htons(vlan->vid);
 		tt_vlan->crc = htonl(vlan->tt.crc);
+		tt_vlan->reserved = 0;
 
 		tt_vlan++;
 	}
@@ -974,6 +975,7 @@ batadv_tt_prepare_tvlv_local_data(struct
 
 		tt_vlan->vid = htons(vlan->vid);
 		tt_vlan->crc = htonl(vlan->tt.crc);
+		tt_vlan->reserved = 0;
 
 		tt_vlan++;
 	}