net: cdc_eem: fix tx fixup skb leak

Message ID 20210616144044.20693-1-linyyuan@codeaurora.org
State New
Headers show
Series
  • net: cdc_eem: fix tx fixup skb leak
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Commit Message

Linyu Yuan June 16, 2021, 2:40 p.m.
when usbnet transmit a skb, eem fixup it in eem_tx_fixup(),
if skb_copy_expand() failed, it return NULL,
usbnet_start_xmit() will have no chance to free original skb.

fix it by free orginal skb in eem_tx_fixup() first,
then check skb clone status, if failed, return NULL to usbnet.

Signed-off-by: Linyu Yuan <linyyuan@codeaurora.org>
---
 drivers/net/usb/cdc_eem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Greg Kroah-Hartman June 16, 2021, 3:05 p.m. | #1
On Wed, Jun 16, 2021 at 10:40:44PM +0800, Linyu Yuan wrote:
> when usbnet transmit a skb, eem fixup it in eem_tx_fixup(),
> if skb_copy_expand() failed, it return NULL,
> usbnet_start_xmit() will have no chance to free original skb.
> 
> fix it by free orginal skb in eem_tx_fixup() first,
> then check skb clone status, if failed, return NULL to usbnet.
> 
> Signed-off-by: Linyu Yuan <linyyuan@codeaurora.org>
> ---
>  drivers/net/usb/cdc_eem.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

What commit does this "Fix:"?  Can you please add that to the
signed-off-by area?

thanks,

greg k-h

Patch

diff --git a/drivers/net/usb/cdc_eem.c b/drivers/net/usb/cdc_eem.c
index 2e60bc1b9a6b..359ea0d10e59 100644
--- a/drivers/net/usb/cdc_eem.c
+++ b/drivers/net/usb/cdc_eem.c
@@ -123,10 +123,10 @@  static struct sk_buff *eem_tx_fixup(struct usbnet *dev, struct sk_buff *skb,
 	}
 
 	skb2 = skb_copy_expand(skb, EEM_HEAD, ETH_FCS_LEN + padlen, flags);
+	dev_kfree_skb_any(skb);
 	if (!skb2)
 		return NULL;
 
-	dev_kfree_skb_any(skb);
 	skb = skb2;
 
 done: