Commit 6d72e7c7 authored by Lv Yunlong's avatar Lv Yunlong Committed by David S. Miller

net:emac/emac-mac: Fix a use after free in emac_mac_tx_buf_send

In emac_mac_tx_buf_send, it calls emac_tx_fill_tpd(..,skb,..).
If some error happens in emac_tx_fill_tpd(), the skb will be freed via
dev_kfree_skb(skb) in error branch of emac_tx_fill_tpd().
But the freed skb is still used via skb->len by netdev_sent_queue(,skb->len).

As i observed that emac_tx_fill_tpd() haven't modified the value of skb->len,
thus my patch assigns skb->len to 'len' before the possible free and
use 'len' instead of skb->len later.

Fixes: b9b17deb ("net: emac: emac gigabit ethernet controller driver")
Signed-off-by: default avatarLv Yunlong <lyl2019@mail.ustc.edu.cn>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f77bd544
......@@ -1437,6 +1437,7 @@ netdev_tx_t emac_mac_tx_buf_send(struct emac_adapter *adpt,
{
struct emac_tpd tpd;
u32 prod_idx;
int len;
memset(&tpd, 0, sizeof(tpd));
......@@ -1456,9 +1457,10 @@ netdev_tx_t emac_mac_tx_buf_send(struct emac_adapter *adpt,
if (skb_network_offset(skb) != ETH_HLEN)
TPD_TYP_SET(&tpd, 1);
len = skb->len;
emac_tx_fill_tpd(adpt, tx_q, skb, &tpd);
netdev_sent_queue(adpt->netdev, skb->len);
netdev_sent_queue(adpt->netdev, len);
/* Make sure the are enough free descriptors to hold one
* maximum-sized SKB. We need one desc for each fragment,
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment