From: Lv Yunlong <lyl2019@mail.ustc.edu.cn> stable inclusion from stable-v4.19.191 commit 16d8c44be52e3650917736d45f5904384a9da834 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I94JI5 CVE: CVE-2021-47013 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 6d72e7c767acbbdd44ebc7d89c6690b405b32b57 ] 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: b9b17debc69d2 ("net: emac: emac gigabit ethernet controller driver") Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com> --- drivers/net/ethernet/qualcomm/emac/emac-mac.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/qualcomm/emac/emac-mac.c b/drivers/net/ethernet/qualcomm/emac/emac-mac.c index 031f6e6ee9c17..351a906980103 100644 --- a/drivers/net/ethernet/qualcomm/emac/emac-mac.c +++ b/drivers/net/ethernet/qualcomm/emac/emac-mac.c @@ -1449,6 +1449,7 @@ int emac_mac_tx_buf_send(struct emac_adapter *adpt, struct emac_tx_queue *tx_q, { struct emac_tpd tpd; u32 prod_idx; + int len; memset(&tpd, 0, sizeof(tpd)); @@ -1468,9 +1469,10 @@ int emac_mac_tx_buf_send(struct emac_adapter *adpt, struct emac_tx_queue *tx_q, 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, -- 2.25.1