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. Implement error handling code on device_init_rd*, device_init_td* and vnt_start for the allocation failures. Signed-off-by: Ji-Hun Kim <ji_hun.kim@xxxxxxxxxxx> --- Changes v5: - Add error handling case for device_alloc_rx_buf() failures. - Add device_free_rx_buf() which is corresponding free function of device_allocated_rx_buf(). And change duplicated codes by this function. - Modify error handling code about freeing allocated value in the loops to more proper ways. - Change goto label names following coding-style conventions. Changes v4: - Fix potential memory leaks from error handling code from device init functions in vnt_start(). Changes v3: - Modify return type of device_init_rd*, device_init_td*. Then add returns error code at those functions and vnt_start as well. Changes v2: - 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, add if statement for freeing to only allocated values. drivers/staging/vt6655/device_main.c | 144 ++++++++++++++++++++++++++++------- 1 file changed, 118 insertions(+), 26 deletions(-) diff --git a/drivers/staging/vt6655/device_main.c b/drivers/staging/vt6655/device_main.c index fbc4bc6..700c03c 100644 --- a/drivers/staging/vt6655/device_main.c +++ b/drivers/staging/vt6655/device_main.c @@ -19,6 +19,7 @@ * device_print_info - print out resource * device_rx_srv - rx service function * device_alloc_rx_buf - rx buffer pre-allocated function + * device_free_rx_buf - free rx buffer function * device_free_tx_buf - free tx buffer function * device_init_rd0_ring- initial rd dma0 ring * device_init_rd1_ring- initial rd dma1 ring @@ -124,14 +125,15 @@ static void device_free_info(struct vnt_private *priv); static void device_print_info(struct vnt_private *priv); -static void device_init_rd0_ring(struct vnt_private *priv); -static void device_init_rd1_ring(struct vnt_private *priv); -static void device_init_td0_ring(struct vnt_private *priv); -static void device_init_td1_ring(struct vnt_private *priv); +static int device_init_rd0_ring(struct vnt_private *priv); +static int device_init_rd1_ring(struct vnt_private *priv); +static int device_init_td0_ring(struct vnt_private *priv); +static int device_init_td1_ring(struct vnt_private *priv); static int device_rx_srv(struct vnt_private *priv, unsigned int idx); static int device_tx_srv(struct vnt_private *priv, unsigned int idx); static bool device_alloc_rx_buf(struct vnt_private *, struct vnt_rx_desc *); +static void device_free_rx_buf(struct vnt_private *priv, struct vnt_rx_desc *rd); static void device_init_registers(struct vnt_private *priv); static void device_free_tx_buf(struct vnt_private *, struct vnt_tx_desc *); static void device_free_td0_ring(struct vnt_private *priv); @@ -528,20 +530,28 @@ static void device_free_rings(struct vnt_private *priv) priv->tx0_bufs, priv->tx_bufs_dma0); } -static void device_init_rd0_ring(struct vnt_private *priv) +static int device_init_rd0_ring(struct vnt_private *priv) { int i; dma_addr_t curr = priv->rd0_pool_dma; struct vnt_rx_desc *desc; + int ret; /* Init the RD0 ring entries */ for (i = 0; i < priv->opts.rx_descs0; 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) { + ret = -ENOMEM; + goto err_free_desc; + } - if (!device_alloc_rx_buf(priv, desc)) + if (!device_alloc_rx_buf(priv, desc)) { dev_err(&priv->pcid->dev, "can not alloc rx bufs\n"); + ret = -ENOMEM; + goto err_free_rd; + } desc->next = &priv->aRD0Ring[(i + 1) % priv->opts.rx_descs0]; desc->next_desc = cpu_to_le32(curr + sizeof(struct vnt_rx_desc)); @@ -550,22 +560,44 @@ 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 0; + +err_free_rd: + kfree(desc->rd_info); + +err_free_desc: + while (--i) { + desc = &priv->aRD0Ring[i]; + device_free_rx_buf(priv, desc); + kfree(desc->rd_info); + } + + return ret; } -static void device_init_rd1_ring(struct vnt_private *priv) +static int device_init_rd1_ring(struct vnt_private *priv) { int i; dma_addr_t curr = priv->rd1_pool_dma; struct vnt_rx_desc *desc; + int ret; /* Init the RD1 ring entries */ for (i = 0; i < priv->opts.rx_descs1; 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) { + ret = -ENOMEM; + goto err_free_desc; + } - if (!device_alloc_rx_buf(priv, desc)) + if (!device_alloc_rx_buf(priv, desc)) { dev_err(&priv->pcid->dev, "can not alloc rx bufs\n"); + ret = -ENOMEM; + goto err_free_rd; + } desc->next = &priv->aRD1Ring[(i+1) % priv->opts.rx_descs1]; desc->next_desc = cpu_to_le32(curr + sizeof(struct vnt_rx_desc)); @@ -574,6 +606,20 @@ 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 0; + +err_free_rd: + kfree(desc->rd_info); + +err_free_desc: + while (--i) { + desc = &priv->aRD1Ring[i]; + device_free_rx_buf(priv, desc); + kfree(desc->rd_info); + } + + return ret; } static void device_free_rd0_ring(struct vnt_private *priv) @@ -582,13 +628,8 @@ static void device_free_rd0_ring(struct vnt_private *priv) for (i = 0; i < priv->opts.rx_descs0; i++) { 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); + device_free_rx_buf(priv, desc); kfree(desc->rd_info); } } @@ -599,28 +640,28 @@ static void device_free_rd1_ring(struct vnt_private *priv) for (i = 0; i < priv->opts.rx_descs1; i++) { 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); + device_free_rx_buf(priv, desc); kfree(desc->rd_info); } } -static void device_init_td0_ring(struct vnt_private *priv) +static int device_init_td0_ring(struct vnt_private *priv) { int i; dma_addr_t curr; struct vnt_tx_desc *desc; + int ret; curr = priv->td0_pool_dma; for (i = 0; i < priv->opts.tx_descs[0]; 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) { + ret = -ENOMEM; + goto err_free_desc; + } desc->td_info->buf = priv->tx0_bufs + i * PKT_BUF_SZ; desc->td_info->buf_dma = priv->tx_bufs_dma0 + i * PKT_BUF_SZ; @@ -632,13 +673,24 @@ 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 0; + +err_free_desc: + while (--i) { + desc = &priv->apTD0Rings[i]; + kfree(desc->td_info); + } + + return ret; } -static void device_init_td1_ring(struct vnt_private *priv) +static int device_init_td1_ring(struct vnt_private *priv) { int i; dma_addr_t curr; struct vnt_tx_desc *desc; + int ret; /* Init the TD ring entries */ curr = priv->td1_pool_dma; @@ -646,6 +698,10 @@ 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) { + ret = -ENOMEM; + goto err_free_desc; + } 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 +713,16 @@ 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 0; + +err_free_desc: + while (--i) { + desc = &priv->apTD1Rings[i]; + kfree(desc->td_info); + } + + return ret; } static void device_free_td0_ring(struct vnt_private *priv) @@ -745,6 +811,16 @@ static bool device_alloc_rx_buf(struct vnt_private *priv, return true; } +static void device_free_rx_buf(struct vnt_private *priv, + struct vnt_rx_desc *rd) +{ + struct vnt_rd_info *rd_info = rd->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); +} + static const u8 fallback_rate0[5][5] = { {RATE_18M, RATE_18M, RATE_12M, RATE_12M, RATE_12M}, {RATE_24M, RATE_24M, RATE_18M, RATE_12M, RATE_12M}, @@ -1165,10 +1241,18 @@ static int vnt_start(struct ieee80211_hw *hw) } dev_dbg(&priv->pcid->dev, "call device init rd0 ring\n"); - device_init_rd0_ring(priv); - device_init_rd1_ring(priv); - device_init_td0_ring(priv); - device_init_td1_ring(priv); + ret = device_init_rd0_ring(priv); + if (ret) + return ret; + ret = device_init_rd1_ring(priv); + if (ret) + goto err_free_rd0_ring; + ret = device_init_td0_ring(priv); + if (ret) + goto err_free_rd1_ring; + ret = device_init_td1_ring(priv); + if (ret) + goto err_free_td0_ring; device_init_registers(priv); @@ -1178,6 +1262,14 @@ static int vnt_start(struct ieee80211_hw *hw) ieee80211_wake_queues(hw); return 0; + +err_free_td0_ring: + device_free_td0_ring(priv); +err_free_rd1_ring: + device_free_rd1_ring(priv); +err_free_rd0_ring: + device_free_rd0_ring(priv); + return ret; } static void vnt_stop(struct ieee80211_hw *hw) -- 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