[PATCH net] bnx2: Fix bug in bnx2_free_tx_skbs().

[PATCH net] bnx2: Fix bug in bnx2_free_tx_skbs().

[Michael Chan]

In rare cases, bnx2x_free_tx_skbs() can unmap the wrong DMA address
when it gets to the last entry of the tx ring.  We were not using
the proper macro to skip the last entry when advancing the tx index.

Reported-by: Zongyun Lai <zlai@vmware.com>
Reviewed-by: Jeffrey Huang <huangjw@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
---
 drivers/net/ethernet/broadcom/bnx2.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnx2.c b/drivers/net/ethernet/broadcom/bnx2.c
index ac7b744..1fa4927 100644
--- a/drivers/net/ethernet/broadcom/bnx2.c
+++ b/drivers/net/ethernet/broadcom/bnx2.c
@@ -5372,7 +5372,7 @@ bnx2_free_tx_skbs(struct bnx2 *bp)
 			int k, last;
 
 			if (skb == NULL) {
-				j++;
+				j = NEXT_TX_BD(j);
 				continue;
 			}
 
@@ -5384,8 +5384,8 @@ bnx2_free_tx_skbs(struct bnx2 *bp)
 			tx_buf->skb = NULL;
 
 			last = tx_buf->nr_frags;
-			j++;
-			for (k = 0; k < last; k++, j++) {
+			j = NEXT_TX_BD(j);
+			for (k = 0; k < last; k++, j = NEXT_TX_BD(j)) {
 				tx_buf = &txr->tx_buf_ring[TX_RING_IDX(j)];
 				dma_unmap_page(&bp->pdev->dev,
 					dma_unmap_addr(tx_buf, mapping),
-- 
1.7.1

Re: [PATCH net] bnx2: Fix bug in bnx2_free_tx_skbs().

[David Miller]

From: "Michael Chan" <mchan@broadcom.com>
Date: Tue, 10 Jul 2012 13:04:40 -0700

> In rare cases, bnx2x_free_tx_skbs() can unmap the wrong DMA address
> when it gets to the last entry of the tx ring.  We were not using
> the proper macro to skip the last entry when advancing the tx index.
> 
> Reported-by: Zongyun Lai <zlai@vmware.com>
> Reviewed-by: Jeffrey Huang <huangjw@broadcom.com>
> Signed-off-by: Michael Chan <mchan@broadcom.com>

Applied and queued up for -stable.