3c505: do not set pcb->data.raw beyond its size

Ensure that we do not set pcb->data.raw beyond its size, print an error message
and return false if we attempt to. A timout message was printed one too early.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 10 deletions

diff --git a/drivers/net/3c505.c b/drivers/net/3c505.c
index 6124605bef0..a8107f992fb 100644
--- a/drivers/net/3c505.c
+++ b/drivers/net/3c505.c
@@ -493,21 +493,27 @@ static bool receive_pcb(struct net_device *dev, pcb_struct * pcb)
         }
         /* read the data */
         spin_lock_irqsave(&adapter->lock, flags);
-        i = 0;
-        do {
-                j = 0;
-                while (((stat = get_status(dev->base_addr)) & ACRF) == 0 && j++ < 20000);
-                pcb->data.raw[i++] = inb_command(dev->base_addr);
-                if (i > MAX_PCB_DATA)
-                        INVALID_PCB_MSG(i);
-        } while ((stat & ASF_PCB_MASK) != ASF_PCB_END && j < 20000);
+        for (i = 0; i < MAX_PCB_DATA; i++) {
+                for (j = 0; j < 20000; j++) {
+                        stat = get_status(dev->base_addr);
+                        if (stat & ACRF)
+                                break;
+                }
+                pcb->data.raw[i] = inb_command(dev->base_addr);
+                if ((stat & ASF_PCB_MASK) == ASF_PCB_END || j >= 20000)
+                        break;
+        }
         spin_unlock_irqrestore(&adapter->lock, flags);
+        if (i >= MAX_PCB_DATA) {
+                INVALID_PCB_MSG(i);
+                return false;
+        }
         if (j >= 20000) {
                 TIMEOUT_MSG(__LINE__);
                 return false;
         }
-        /* woops, the last "data" byte was really the length! */
-        total_length = pcb->data.raw[--i];
+        /* the last "data" byte was really the length! */
+        total_length = pcb->data.raw[i];
 
         /* safety check total length vs data length */
         if (total_length != (pcb->length + 2)) {