Commit b7aa39a2 authored Nov 05, 2019 by Pan Bian Committed by Greg Kroah-Hartman Nov 05, 2019

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@163.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/1572965351-6745-1-git-send-email-bianpan2016@163.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 78ce93f3

drivers/staging/rtl8192e/rtl8192e/rtl_core.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -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)

Admin message