| From cdb87cbbf063744794de130ce9018981ab0b7ffe Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Sun, 2 May 2021 04:58:18 -0700 |
| Subject: ethernet:enic: Fix a use after free bug in enic_hard_start_xmit |
| |
| From: Lv Yunlong <lyl2019@mail.ustc.edu.cn> |
| |
| [ 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> |
| --- |
| 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 fb269d587b74..548d8095c0a7 100644 |
| --- a/drivers/net/ethernet/cisco/enic/enic_main.c |
| +++ b/drivers/net/ethernet/cisco/enic/enic_main.c |
| @@ -768,7 +768,7 @@ 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; |
| @@ -814,6 +814,7 @@ 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 */ |
| @@ -857,7 +858,8 @@ 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); |
| @@ -865,6 +867,7 @@ static netdev_tx_t enic_hard_start_xmit(struct sk_buff *skb, |
| if (!netdev_xmit_more() || netif_xmit_stopped(txq)) |
| vnic_wq_doorbell(wq); |
| |
| +error: |
| spin_unlock(&enic->wq_lock[txq_map]); |
| |
| return NETDEV_TX_OK; |
| -- |
| 2.30.2 |
| |