Patch "staging: rtl8192e: rtl92e_fill_tx_desc fix write to mapped out memory." has been added to the 4.11-stable tree

This is a note to let you know that I've just added the patch titled

staging: rtl8192e: rtl92e_fill_tx_desc fix write to mapped out memory.

to the 4.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
staging-rtl8192e-rtl92e_fill_tx_desc-fix-write-to-mapped-out-memory.patch
and it can be found in the queue-4.11 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Malcolm Priestley <[email protected]>
Date: Thu, 11 May 2017 18:57:43 +0100
Subject: staging: rtl8192e: rtl92e_fill_tx_desc fix write to mapped out memory.

From: Malcolm Priestley <[email protected]>

commit baabd567f87be05330faa5140f72a91960e7405a upstream.

The driver attempts to alter memory that is mapped to PCI device.

This is because tx_fwinfo_8190pci points to skb->data

Move the pci_map_single to when completed buffer is ready to be mapped with psdec is empty to drop on mapping error.

---
 drivers/staging/rtl8192e/rtl8192e/r8192E_dev.c |   13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

@@ -1184,8 +1184,7 @@ void  rtl92e_fill_tx_desc(struct net_dev
 			  struct cb_desc *cb_desc, struct sk_buff *skb)
 {
 	struct r8192_priv *priv = rtllib_priv(dev);
-	dma_addr_t mapping = pci_map_single(priv->pdev, skb->data, skb->len,
-			 PCI_DMA_TODEVICE);
+	dma_addr_t mapping;
 	struct tx_fwinfo_8190pci *pTxFwInfo;
 
 	pTxFwInfo = (struct tx_fwinfo_8190pci *)skb->data;

@@ -1196,8 +1195,6 @@ void  rtl92e_fill_tx_desc(struct net_dev
 	pTxFwInfo->Short = _rtl92e_query_is_short(pTxFwInfo->TxHT,
 						  pTxFwInfo->TxRate, cb_desc);
 
-	if (pci_dma_mapping_error(priv->pdev, mapping))
-		netdev_err(dev, "%s(): DMA Mapping error\n", __func__);
 	if (cb_desc->bAMPDUEnable) {
 		pTxFwInfo->AllowAggregation = 1;
 		pTxFwInfo->RxMF = cb_desc->ampdu_factor;

@@ -1232,6 +1229,14 @@ void  rtl92e_fill_tx_desc(struct net_dev
 	}
 
 	memset((u8 *)pdesc, 0, 12);
+
+	mapping = pci_map_single(priv->pdev, skb->data, skb->len,
+				 PCI_DMA_TODEVICE);
+	if (pci_dma_mapping_error(priv->pdev, mapping)) {
+		netdev_err(dev, "%s(): DMA Mapping error\n", __func__);
+		return;
+	}
+
 	pdesc->LINIP = 0;
 	pdesc->CmdInit = 1;
 	pdesc->Offset = sizeof(struct tx_fwinfo_8190pci) + 8;

Patches currently in stable-queue which might be from [email protected] are

queue-4.11/staging-rtl8192e-rtl92e_get_eeprom_size-fix-read-size-of-eprom_cmd.patch queue-4.11/staging-rtl8192e-getts-fix-invalid-tid-7-warning.patch queue-4.11/staging-rtl8192e-rtl92e_fill_tx_desc-fix-write-to-mapped-out-memory.patch queue-4.11/staging-rtl8192e-fix-2-byte-alignment-of-register-bssidr.patch