[ Upstream commit cfef46d692efd852a0da6803f920cc756eea2855 ]
When a Tx timestamp is requested, a pointer to the skb is stored in the ravb_tstamp_skb struct. This was done without an skb_get. There exists the possibility that the skb could be freed by ravb_tx_free (when ravb_tx_free is called from ravb_start_xmit) before the timestamp was processed, leading to a use-after-free bug.
Use skb_get when filling a ravb_tstamp_skb struct, and add appropriate frees/consumes when a ravb_tstamp_skb struct is freed.
Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper") Signed-off-by: Tho Vu tho.vu.wh@rvc.renesas.com Signed-off-by: Kazuya Mizuguchi kazuya.mizuguchi.ks@renesas.com Signed-off-by: Simon Horman horms+renesas@verge.net.au Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/renesas/ravb_main.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c index ce79af4a7f6fb..d73617cc3b159 100644 --- a/drivers/net/ethernet/renesas/ravb_main.c +++ b/drivers/net/ethernet/renesas/ravb_main.c @@ -1,6 +1,6 @@ /* Renesas Ethernet AVB device driver * - * Copyright (C) 2014-2015 Renesas Electronics Corporation + * Copyright (C) 2014-2019 Renesas Electronics Corporation * Copyright (C) 2015 Renesas Solutions Corp. * Copyright (C) 2015-2016 Cogent Embedded, Inc. source@cogentembedded.com * @@ -513,7 +513,10 @@ static void ravb_get_tx_tstamp(struct net_device *ndev) kfree(ts_skb); if (tag == tfa_tag) { skb_tstamp_tx(skb, &shhwtstamps); + dev_consume_skb_any(skb); break; + } else { + dev_kfree_skb_any(skb); } } ravb_modify(ndev, TCCR, TCCR_TFR, TCCR_TFR); @@ -1576,7 +1579,7 @@ static netdev_tx_t ravb_start_xmit(struct sk_buff *skb, struct net_device *ndev) DMA_TO_DEVICE); goto unmap; } - ts_skb->skb = skb; + ts_skb->skb = skb_get(skb); ts_skb->tag = priv->ts_skb_tag++; priv->ts_skb_tag &= 0x3ff; list_add_tail(&ts_skb->list, &priv->ts_skb_list); @@ -1704,6 +1707,7 @@ static int ravb_close(struct net_device *ndev) /* Clear the timestamp list */ list_for_each_entry_safe(ts_skb, ts_skb2, &priv->ts_skb_list, list) { list_del(&ts_skb->list); + kfree_skb(ts_skb->skb); kfree(ts_skb); }