batman-adv: initialize "struct batadv_tvlv_tt_vlan_data"->reserved field

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@syzkaller.appspotmail.com>
Tested-by: syzbot <syzbot+50ee810676e6a089487b@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
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@narfation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index 06f366d234ffb2a78ee72e9d94071104cf77029a..5f976485e8c64c0dbcf32ada2fad0a9d4aed73c4 100644 (file)
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -871,6 +871,7 @@ batadv_tt_prepare_tvlv_local_data(struct batadv_priv *bat_priv,
 
                tt_vlan->vid = htons(vlan->vid);
                tt_vlan->crc = htonl(vlan->tt.crc);
+               tt_vlan->reserved = 0;
 
                tt_vlan++;
        }