This is a note to let you know that I've just added the patch titled
net:emac/emac-mac: Fix a use after free in emac_mac_tx_buf_send
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-emac-emac-mac-fix-a-use-after-free-in-emac_mac_t.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit f6e43a0014a204249734f25cc0cc5dd45826cc09
Author: Lv Yunlong <lyl2019@xxxxxxxxxxxxxxxx>
Date: Mon Apr 26 09:06:25 2021 -0700
net:emac/emac-mac: Fix a use after free in emac_mac_tx_buf_send
[ 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@xxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/ethernet/qualcomm/emac/emac-mac.c b/drivers/net/ethernet/qualcomm/emac/emac-mac.c
index 117188e3c7de..87b8c032195d 100644
--- a/drivers/net/ethernet/qualcomm/emac/emac-mac.c
+++ b/drivers/net/ethernet/qualcomm/emac/emac-mac.c
@@ -1437,6 +1437,7 @@ netdev_tx_t emac_mac_tx_buf_send(struct emac_adapter *adpt,
{
struct emac_tpd tpd;
u32 prod_idx;
+ int len;
memset(&tpd, 0, sizeof(tpd));
@@ -1456,9 +1457,10 @@ netdev_tx_t emac_mac_tx_buf_send(struct emac_adapter *adpt,
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,
