brcmfmac: fix memory leakage in msgbuf

Author: Arend van Spriel <arend@broadcom.com>

The kbuild robot came up with the following warning:

tree:   .../kernel/git/linville/wireless-next.git master
head:   dc6be9f54a4ecb0a09765d1f515ed947d86b7528
commit: 9a1bb60250d2b6b546a62e5b73f55c4f1d22016b
	 [5/13] brcmfmac: Adding msgbuf protocol.

coccinelle warnings:
 drivers/net/wireless/brcm80211/brcmfmac/msgbuf.c:1309:1-28:
   alloc with no test, possible model on line 1318

Looking into the issue, it turned out that the referred allocation
buffer was not being released in failure path nor upon module
unload.

Reported-by: Fengguang Wu 
Reviewed-by: Franky (Zhenhui) Lin 
Reviewed-by: Daniel (Deognyoun) Kim 
Reviewed-by: Pieter-Paul Giesberts 
Signed-off-by: Arend van Spriel 
Signed-off-by: John W. Linville 
---
 drivers/net/wireless/brcm80211/brcmfmac/msgbuf.c | 4 ++++
 1 file changed, 4 insertions(+)
 
diff --git a/drivers/net/wireless/brcm80211/brcmfmac/msgbuf.c b/drivers/net/wireless/brcm80211/brcmfmac/msgbuf.c
index 535c7eb..8f8b937 100644
--- a/drivers/net/wireless/brcm80211/brcmfmac/msgbuf.c
+++ b/drivers/net/wireless/brcm80211/brcmfmac/msgbuf.c
@@ -1318,6 +1318,8 @@ int brcmf_proto_msgbuf_attach(struct brcmf_pub *drvr)
 	msgbuf->nrof_flowrings = if_msgbuf->nrof_flowrings;
 	msgbuf->flowring_dma_handle = kzalloc(msgbuf->nrof_flowrings *
 		sizeof(*msgbuf->flowring_dma_handle), GFP_ATOMIC);
+	if (!msgbuf->flowring_dma_handle)
+		goto fail;
 
 	msgbuf->rx_dataoffset = if_msgbuf->rx_dataoffset;
 	msgbuf->max_rxbufpost = if_msgbuf->max_rxbufpost;
@@ -1362,6 +1364,7 @@ fail:
 		kfree(msgbuf->flow_map);
 		kfree(msgbuf->txstatus_done_map);
 		brcmf_msgbuf_release_pktids(msgbuf);
+		kfree(msgbuf->flowring_dma_handle);
 		if (msgbuf->ioctbuf)
 			dma_free_coherent(drvr->bus_if->dev,
 					  BRCMF_TX_IOCTL_MAX_MSG_SIZE,
@@ -1391,6 +1394,7 @@ void brcmf_proto_msgbuf_detach(struct brcmf_pub *drvr)
 				  BRCMF_TX_IOCTL_MAX_MSG_SIZE,
 				  msgbuf->ioctbuf, msgbuf->ioctbuf_handle);
 		brcmf_msgbuf_release_pktids(msgbuf);
+		kfree(msgbuf->flowring_dma_handle);
 		kfree(msgbuf);
 		drvr->proto->pd = NULL;
 	}