There are no null pointer checking on rd_info and td_info values which are allocated by kzalloc. It has potential null pointer dereferencing issues. Add return when allocation is failed. Signed-off-by: Ji-Hun Kim <ji_hun.kim@xxxxxxxxxxx> --- Change: since v1: - Delete WARN_ON which can makes crashes on some machines. - Instead of return directly, goto freeing function for freeing previously allocated memory in the for loop after kzalloc() failed. - In the freeing function, if td_info and rd_info are not allocated, no needs to free. drivers/staging/vt6655/device_main.c | 64 +++++++++++++++++++++++++----------- 1 file changed, 44 insertions(+), 20 deletions(-) diff --git a/drivers/staging/vt6655/device_main.c b/drivers/staging/vt6655/device_main.c index fbc4bc6..ecbba43 100644 --- a/drivers/staging/vt6655/device_main.c +++ b/drivers/staging/vt6655/device_main.c @@ -539,7 +539,8 @@ static void device_init_rd0_ring(struct vnt_private *priv) i ++, curr += sizeof(struct vnt_rx_desc)) { desc = &priv->aRD0Ring[i]; desc->rd_info = kzalloc(sizeof(*desc->rd_info), GFP_KERNEL); - + if (!desc->rd_info) + goto error; if (!device_alloc_rx_buf(priv, desc)) dev_err(&priv->pcid->dev, "can not alloc rx bufs\n"); @@ -550,6 +551,10 @@ static void device_init_rd0_ring(struct vnt_private *priv) if (i > 0) priv->aRD0Ring[i-1].next_desc = cpu_to_le32(priv->rd0_pool_dma); priv->pCurrRD[0] = &priv->aRD0Ring[0]; + + return; +error: + device_free_rd0_ring(priv); } static void device_init_rd1_ring(struct vnt_private *priv) @@ -563,7 +568,8 @@ static void device_init_rd1_ring(struct vnt_private *priv) i ++, curr += sizeof(struct vnt_rx_desc)) { desc = &priv->aRD1Ring[i]; desc->rd_info = kzalloc(sizeof(*desc->rd_info), GFP_KERNEL); - + if (!desc->rd_info) + goto error; if (!device_alloc_rx_buf(priv, desc)) dev_err(&priv->pcid->dev, "can not alloc rx bufs\n"); @@ -574,6 +580,10 @@ static void device_init_rd1_ring(struct vnt_private *priv) if (i > 0) priv->aRD1Ring[i-1].next_desc = cpu_to_le32(priv->rd1_pool_dma); priv->pCurrRD[1] = &priv->aRD1Ring[0]; + + return; +error: + device_free_rd1_ring(priv); } static void device_free_rd0_ring(struct vnt_private *priv) @@ -584,12 +594,12 @@ static void device_free_rd0_ring(struct vnt_private *priv) struct vnt_rx_desc *desc = &priv->aRD0Ring[i]; struct vnt_rd_info *rd_info = desc->rd_info; - dma_unmap_single(&priv->pcid->dev, rd_info->skb_dma, - priv->rx_buf_sz, DMA_FROM_DEVICE); - - dev_kfree_skb(rd_info->skb); - - kfree(desc->rd_info); + if (rd_info) { + dma_unmap_single(&priv->pcid->dev, rd_info->skb_dma, + priv->rx_buf_sz, DMA_FROM_DEVICE); + dev_kfree_skb(rd_info->skb); + kfree(desc->rd_info); + } } } @@ -601,12 +611,12 @@ static void device_free_rd1_ring(struct vnt_private *priv) struct vnt_rx_desc *desc = &priv->aRD1Ring[i]; struct vnt_rd_info *rd_info = desc->rd_info; - dma_unmap_single(&priv->pcid->dev, rd_info->skb_dma, - priv->rx_buf_sz, DMA_FROM_DEVICE); - - dev_kfree_skb(rd_info->skb); - - kfree(desc->rd_info); + if (rd_info) { + dma_unmap_single(&priv->pcid->dev, rd_info->skb_dma, + priv->rx_buf_sz, DMA_FROM_DEVICE); + dev_kfree_skb(rd_info->skb); + kfree(desc->rd_info); + } } } @@ -621,7 +631,8 @@ static void device_init_td0_ring(struct vnt_private *priv) i++, curr += sizeof(struct vnt_tx_desc)) { desc = &priv->apTD0Rings[i]; desc->td_info = kzalloc(sizeof(*desc->td_info), GFP_KERNEL); - + if (!desc->td_info) + goto error; desc->td_info->buf = priv->tx0_bufs + i * PKT_BUF_SZ; desc->td_info->buf_dma = priv->tx_bufs_dma0 + i * PKT_BUF_SZ; @@ -632,6 +643,10 @@ static void device_init_td0_ring(struct vnt_private *priv) if (i > 0) priv->apTD0Rings[i-1].next_desc = cpu_to_le32(priv->td0_pool_dma); priv->apTailTD[0] = priv->apCurrTD[0] = &priv->apTD0Rings[0]; + + return; +error: + device_free_td0_ring(priv); } static void device_init_td1_ring(struct vnt_private *priv) @@ -646,7 +661,8 @@ static void device_init_td1_ring(struct vnt_private *priv) i++, curr += sizeof(struct vnt_tx_desc)) { desc = &priv->apTD1Rings[i]; desc->td_info = kzalloc(sizeof(*desc->td_info), GFP_KERNEL); - + if (!desc->td_info) + goto error; desc->td_info->buf = priv->tx1_bufs + i * PKT_BUF_SZ; desc->td_info->buf_dma = priv->tx_bufs_dma1 + i * PKT_BUF_SZ; @@ -657,6 +673,10 @@ static void device_init_td1_ring(struct vnt_private *priv) if (i > 0) priv->apTD1Rings[i-1].next_desc = cpu_to_le32(priv->td1_pool_dma); priv->apTailTD[1] = priv->apCurrTD[1] = &priv->apTD1Rings[0]; + + return; +error: + device_free_td1_ring(priv); } static void device_free_td0_ring(struct vnt_private *priv) @@ -667,8 +687,10 @@ static void device_free_td0_ring(struct vnt_private *priv) struct vnt_tx_desc *desc = &priv->apTD0Rings[i]; struct vnt_td_info *td_info = desc->td_info; - dev_kfree_skb(td_info->skb); - kfree(desc->td_info); + if (td_info) { + dev_kfree_skb(td_info->skb); + kfree(desc->td_info); + } } } @@ -680,8 +702,10 @@ static void device_free_td1_ring(struct vnt_private *priv) struct vnt_tx_desc *desc = &priv->apTD1Rings[i]; struct vnt_td_info *td_info = desc->td_info; - dev_kfree_skb(td_info->skb); - kfree(desc->td_info); + if (td_info) { + dev_kfree_skb(td_info->skb); + kfree(desc->td_info); + } } } -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html