From: Lv Yunlong lyl2019@mail.ustc.edu.cn

stable inclusion from stable-v4.19.191 commit 25a87b1f566b5eb2af2857a928f0e2310d900976 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I94JCD CVE: CVE-2021-46998

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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[ Upstream commit 643001b47adc844ae33510c4bb93c236667008a3 ]

In enic_hard_start_xmit, it calls enic_queue_wq_skb(). Inside enic_queue_wq_skb, if some error happens, the skb will be freed by dev_kfree_skb(skb). But the freed skb is still used in skb_tx_timestamp(skb).

My patch makes enic_queue_wq_skb() return error and goto spin_unlock() incase of error. The solution is provided by Govind. See https://lkml.org/lkml/2021/4/30/961.

Fixes: fb7516d42478e ("enic: add sw timestamp support") Signed-off-by: Lv Yunlong lyl2019@mail.ustc.edu.cn Acked-by: Govindarajulu Varadarajan gvaradar@cisco.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Liu Jian liujian56@huawei.com --- drivers/net/ethernet/cisco/enic/enic_main.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/cisco/enic/enic_main.c b/drivers/net/ethernet/cisco/enic/enic_main.c index 733d9172425b..f8e82bc55f0f 100644 --- a/drivers/net/ethernet/cisco/enic/enic_main.c +++ b/drivers/net/ethernet/cisco/enic/enic_main.c @@ -803,7 +803,7 @@ static inline int enic_queue_wq_skb_encap(struct enic *enic, struct vnic_wq *wq, return err; }

-static inline void enic_queue_wq_skb(struct enic *enic, +static inline int enic_queue_wq_skb(struct enic *enic, struct vnic_wq *wq, struct sk_buff *skb) { unsigned int mss = skb_shinfo(skb)->gso_size; @@ -849,6 +849,7 @@ static inline void enic_queue_wq_skb(struct enic *enic, wq->to_use = buf->next; dev_kfree_skb(skb); } + return err; }

/* netif_tx_lock held, process context with BHs disabled, or BH */ @@ -892,7 +893,8 @@ static netdev_tx_t enic_hard_start_xmit(struct sk_buff *skb, return NETDEV_TX_BUSY; }

- enic_queue_wq_skb(enic, wq, skb); + if (enic_queue_wq_skb(enic, wq, skb)) + goto error;

if (vnic_wq_desc_avail(wq) < MAX_SKB_FRAGS + ENIC_DESC_MAX_SPLITS) netif_tx_stop_queue(txq); @@ -900,6 +902,7 @@ static netdev_tx_t enic_hard_start_xmit(struct sk_buff *skb, if (!skb->xmit_more || netif_xmit_stopped(txq)) vnic_wq_doorbell(wq);

+error: spin_unlock(&enic->wq_lock[txq_map]);

return NETDEV_TX_OK;