This is a note to let you know that I've just added the patch titled
staging: rtl8192e: fix potential use after free
to my staging git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git
in the staging-testing branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will be merged to the staging-next branch sometime soon,
after it passes testing, and the merge window is open.
If you have any questions about this process, please let me know.
>From b7aa39a2ed0112d07fc277ebd24a08a7b2368ab9 Mon Sep 17 00:00:00 2001
From: Pan Bian <bianpan2016@xxxxxxx>
Date: Tue, 5 Nov 2019 22:49:11 +0800
Subject: staging: rtl8192e: fix potential use after free
The variable skb is released via kfree_skb() when the return value of
_rtl92e_tx is not zero. However, after that, skb is accessed again to
read its length, which may result in a use after free bug. This patch
fixes the bug by moving the release operation to where skb is never
used later.
Signed-off-by: Pan Bian <bianpan2016@xxxxxxx>
Reviewed-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/1572965351-6745-1-git-send-email-bianpan2016@xxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/rtl8192e/rtl8192e/rtl_core.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/rtl8192e/rtl8192e/rtl_core.c b/drivers/staging/rtl8192e/rtl8192e/rtl_core.c
index b08712a9c029..dace81a7d1ba 100644
--- a/drivers/staging/rtl8192e/rtl8192e/rtl_core.c
+++ b/drivers/staging/rtl8192e/rtl8192e/rtl_core.c
@@ -1616,14 +1616,15 @@ static void _rtl92e_hard_data_xmit(struct sk_buff *skb, struct net_device *dev,
memcpy((unsigned char *)(skb->cb), &dev, sizeof(dev));
skb_push(skb, priv->rtllib->tx_headroom);
ret = _rtl92e_tx(dev, skb);
- if (ret != 0)
- kfree_skb(skb);
if (queue_index != MGNT_QUEUE) {
priv->rtllib->stats.tx_bytes += (skb->len -
priv->rtllib->tx_headroom);
priv->rtllib->stats.tx_packets++;
}
+
+ if (ret != 0)
+ kfree_skb(skb);
}
static int _rtl92e_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
--
2.23.0
