[PATCH] mwifiex: pcie: tighten a check in mwifiex_pcie_process_event_ready()

[Dan Carpenter]

If "evt_len" is 1 then we try to memcpy() negative 3 bytes and it would
cause memory corruption.

Fixes: d930faee141b ("mwifiex: add support for Marvell pcie8766 chipset")
Signed-off-by: Dan Carpenter <dan.carpen...@oracle.com>

diff --git a/drivers/net/wireless/marvell/mwifiex/pcie.c 
b/drivers/net/wireless/marvell/mwifiex/pcie.c
index 97a6199692ab..7538543d46fa 100644
--- a/drivers/net/wireless/marvell/mwifiex/pcie.c
+++ b/drivers/net/wireless/marvell/mwifiex/pcie.c
@@ -1881,7 +1881,8 @@ static int mwifiex_pcie_process_event_ready(struct 
mwifiex_adapter *adapter)
                mwifiex_dbg(adapter, EVENT,
                            "info: Event length: %d\n", evt_len);
 
-               if ((evt_len > 0) && (evt_len  < MAX_EVENT_SIZE))
+               if (evt_len > MWIFIEX_EVENT_HEADER_LEN &&
+                   evt_len < MAX_EVENT_SIZE)
                        memcpy(adapter->event_body, skb_cmd->data +
                               MWIFIEX_EVENT_HEADER_LEN, evt_len -
                               MWIFIEX_EVENT_HEADER_LEN);