[PATCH v2] ethernet:enic: Fix a use after free bug in enic_hard_start_xmit
From: Lv Yunlong <hidden>
Date: 2021-05-02 11:58:44
Also in:
lkml
Subsystem:
cisco vic ethernet nic driver, networking drivers, the rest · Maintainers:
Satish Kharat, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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 <redacted> --- 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 f04ec53544ae..b1443ff439de 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;
--
2.25.1