Messages in this thread Patch in this message | | | From | "Jason A. Donenfeld" <> | Subject | [PATCH] e1000: free skb when returning on -ENOMEM error | Date | Thu, 22 Oct 2015 17:27:22 +0200 |
| |
eth_skb_pad returns 0 if it was successful, or -ENOMEM if it was not. In that case, this function exits early. Some early exits return with NETDEV_TX_BUSY, which queues the skb up to be tried again, and so the skb should not be freed. Other early exits return with NETDEV_TX_OK, like this one, in which case it's imperative that the skb is freed, since it is not queued back up. In this case, upon receiving -ENOMEM from eth_skb_pad, the function exits early with NETDEV_TX_OK, but forgets to free the skb. This patch fixes that.
In a low memory situation, in which the GFP_ATOMIC allocation from eth_skb_pad fails, if a network device is transmitting repeatedly, this bug could lead to rapidly leaking memory that could only be recovered by a reboot or crash.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> --- drivers/net/ethernet/intel/e1000/e1000_main.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c index 74dc150..0d6b4c8 100644 --- a/drivers/net/ethernet/intel/e1000/e1000_main.c +++ b/drivers/net/ethernet/intel/e1000/e1000_main.c @@ -3130,8 +3130,10 @@ static netdev_tx_t e1000_xmit_frame(struct sk_buff *skb, * packets may get corrupted during padding by HW. * To WA this issue, pad all small packets manually. */ - if (eth_skb_pad(skb)) + if (eth_skb_pad(skb)) { + dev_kfree_skb_any(skb); return NETDEV_TX_OK; + } mss = skb_shinfo(skb)->gso_size; /* The controller does a simple calculation to -- 2.6.2
| |