[PATCH AUTOSEL 5.2 46/76] ravb: Fix use-after-free ravb_tstamp_skb
From: Sasha Levin <sashal@kernel.org>
Date: 2019-08-29 18:29:35
Also in:
linux-renesas-soc, lkml, stable
Subsystem:
networking drivers, renesas ethernet avb driver, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Niklas Söderlund, Linus Torvalds
From: Tho Vu <redacted>
[ 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 <redacted>
Signed-off-by: Kazuya Mizuguchi <redacted>
Signed-off-by: Simon Horman <redacted>
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 ef8f08931fe8b..6cacd5e893aca 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c@@ -1,7 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 /* 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);
@@ -1564,7 +1567,7 @@ static netdev_tx_t ravb_start_xmit(struct sk_buff *skb, struct net_device *ndev) } 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);
@@ -1693,6 +1696,7 @@ 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); }
--
2.20.1