From 626b598aa8becc95ad1c56e721c90ddfc6a8c409 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Fri, 9 Apr 2021 15:24:28 +0300 Subject: [PATCH] net: enetc: fix array underflow in error handling code This loop will try to unmap enetc_unmap_tx_buff[-1] and crash. Fixes: 9d2b68cc108d ("net: enetc: add support for XDP_REDIRECT") Signed-off-by: Dan Carpenter Reviewed-by: Claudiu Manoil Reviewed-by: Vladimir Oltean Link: https://lore.kernel.org/r/YHBHfCY/yv3EnM9z@mwanda Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/freescale/enetc/enetc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c index 57049ae..d863957 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc.c +++ b/drivers/net/ethernet/freescale/enetc/enetc.c @@ -895,7 +895,7 @@ static int enetc_xdp_frame_to_xdp_tx_swbd(struct enetc_bdr *tx_ring, dma = dma_map_single(tx_ring->dev, data, len, DMA_TO_DEVICE); if (unlikely(dma_mapping_error(tx_ring->dev, dma))) { /* Undo the DMA mapping for all fragments */ - while (n-- >= 0) + while (--n >= 0) enetc_unmap_tx_buff(tx_ring, &xdp_tx_arr[n]); netdev_err(tx_ring->ndev, "DMA map error\n"); -- 2.7.4