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=...

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[ 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,