Re: [PATCH net] net: vertexcom: mse102x: Fix possible double free of TX skb

quoted

Isn't it easier to change this function to free the copy rather than
the original? That way the original will remain valid for the callers.  

You mean something like this?

diff --git a/drivers/net/ethernet/vertexcom/mse102x.c

b/drivers/net/ethernet/vertexcom/mse102x.c
index a04d4073def9..2c37957478fb 100644

--- a/drivers/net/ethernet/vertexcom/mse102x.c
+++ b/drivers/net/ethernet/vertexcom/mse102x.c

@@ -222,7 +222,7 @@ static int mse102x_tx_frame_spi(struct mse102x_net

*mse, struct sk_buff *txp,
      struct mse102x_net_spi *mses = to_mse102x_spi(mse);
      struct spi_transfer *xfer = &mses->spi_xfer;
      struct spi_message *msg = &mses->spi_msg;
-    struct sk_buff *tskb;
+    struct sk_buff *tskb = NULL;
      int ret;

      netif_dbg(mse, tx_queued, mse->ndev, "%s: skb %p, %d@%p\n",

@@ -235,7 +235,6 @@ static int mse102x_tx_frame_spi(struct mse102x_net

*mse, struct sk_buff *txp,
          if (!tskb)
              return -ENOMEM;

-        dev_kfree_skb(txp);
          txp = tskb;
      }

@@ -257,6 +256,8 @@ static int mse102x_tx_frame_spi(struct mse102x_net

*mse, struct sk_buff *txp,
          mse->stats.xfer_err++;
      }

+    dev_kfree_skb(tskb);
+
      return ret;
  }