b43: allocate receive buffers big enough for max frame len + offset

Otherwise, skb_put inside of dma_rx can fail...

	https://bugzilla.kernel.org/show_bug.cgi?id=32042

Signed-off-by: John W. Linville <linville@tuxdriver.com>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: stable@kernel.org

drivers/net/wireless/b43/dma.c

@@ -1536,7 +1536,7 @@ static void dma_rx(struct b43_dmaring *ring, int *slot)
 		dmaaddr = meta->dmaaddr;
 		goto drop_recycle_buffer;
 	}
-	if (unlikely(len > ring->rx_buffersize)) {
+	if (unlikely(len + ring->frameoffset > ring->rx_buffersize)) {
 		/* The data did not fit into one descriptor buffer
 		 * and is split over multiple buffers.
 		 * This should never happen, as we try to allocate buffers

drivers/net/wireless/b43/dma.h

@@ -163,7 +163,7 @@ struct b43_dmadesc_generic {
 /* DMA engine tuning knobs */
 #define B43_TXRING_SLOTS		256
 #define B43_RXRING_SLOTS		64
-#define B43_DMA0_RX_BUFFERSIZE		IEEE80211_MAX_FRAME_LEN
+#define B43_DMA0_RX_BUFFERSIZE		(B43_DMA0_RX_FRAMEOFFSET + IEEE80211_MAX_FRAME_LEN)
 
 /* Pointer poison */
 #define B43_DMA_PTR_POISON		((void *)ERR_PTR(-ENOMEM))