[PATCH 4.4 03/91] rapidio/rionet: do not free skb before reading its length

From: Greg Kroah-Hartman
Date: Tue Dec 11 2018 - 10:45:08 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Pan Bian <bianpan2016@xxxxxxx>

[ Upstream commit cfc435198f53a6fa1f656d98466b24967ff457d0 ]

skb is freed via dev_kfree_skb_any, however, skb->len is read then. This
may result in a use-after-free bug.

Fixes: e6161d64263 ("rapidio/rionet: rework driver initialization and removal")
Signed-off-by: Pan Bian <bianpan2016@xxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/rionet.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/rionet.c
+++ b/drivers/net/rionet.c
@@ -215,9 +215,9 @@ static int rionet_start_xmit(struct sk_b
* it just report sending a packet to the target
* (without actual packet transfer).
*/
- dev_kfree_skb_any(skb);
ndev->stats.tx_packets++;
ndev->stats.tx_bytes += skb->len;
+ dev_kfree_skb_any(skb);
}
}