[net,1/3] net: dsa: rtl4_a: Pad using __skb_put_padto()

Message ID 20210301133241.1277164-1-linus.walleij@linaro.org
State New
Headers show
Series
  • [net,1/3] net: dsa: rtl4_a: Pad using __skb_put_padto()
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Commit Message

Linus Walleij March 1, 2021, 1:32 p.m.
The eth_skb_pad() function will cause a double free
on failure since dsa_slave_xmit() will try to free
the frame if we return NULL. Fix this by using
__skb_put_padto() instead.

Fixes: 86dd9868b878 ("net: dsa: tag_rtl4_a: Support also egress tags")
Reported-by: DENG Qingfang <dqfext@gmail.com>
Cc: Mauri Sandberg <sandberg@mailfence.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

---
 net/dsa/tag_rtl4_a.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

-- 
2.29.2

Comments

Florian Fainelli March 2, 2021, 1:41 a.m. | #1
On 3/1/2021 5:32 AM, Linus Walleij wrote:
> The eth_skb_pad() function will cause a double free
> on failure since dsa_slave_xmit() will try to free
> the frame if we return NULL. Fix this by using
> __skb_put_padto() instead.
> 
> Fixes: 86dd9868b878 ("net: dsa: tag_rtl4_a: Support also egress tags")
> Reported-by: DENG Qingfang <dqfext@gmail.com>
> Cc: Mauri Sandberg <sandberg@mailfence.com>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>

Patch

diff --git a/net/dsa/tag_rtl4_a.c b/net/dsa/tag_rtl4_a.c
index c17d39b4a1a0..804d756dd80a 100644
--- a/net/dsa/tag_rtl4_a.c
+++ b/net/dsa/tag_rtl4_a.c
@@ -40,7 +40,7 @@  static struct sk_buff *rtl4a_tag_xmit(struct sk_buff *skb,
 	u16 out;
 
 	/* Pad out to at least 60 bytes */
-	if (unlikely(eth_skb_pad(skb)))
+	if (__skb_put_padto(skb, ETH_ZLEN, false))
 		return NULL;
 	if (skb_cow_head(skb, RTL4_A_HDR_LEN) < 0)
 		return NULL;