s390/qeth: don't process empty bridge port events

Discard events that don't contain any entries. This shouldn't happen,
but subsequent code relies on being able to use entry 0. So better
be safe than accessing garbage.

Fixes: b4d72c08b358 ("qeth: bridgeport support - basic control")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c
index 38e97bbde9edcf74f8e29e7b0fd495c24baed4e1..8b342a88ff5cb9c8ab8d0c5e49ee655632fa78f9 100644 (file)
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -1140,6 +1140,10 @@ static void qeth_bridge_state_change(struct qeth_card *card,
        int extrasize;
 
        QETH_CARD_TEXT(card, 2, "brstchng");
+       if (qports->num_entries == 0) {
+               QETH_CARD_TEXT(card, 2, "BPempty");
+               return;
+       }
        if (qports->entry_length != sizeof(struct qeth_sbp_port_entry)) {
                QETH_CARD_TEXT_(card, 2, "BPsz%04x", qports->entry_length);
                return;