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authorVincent Mailhol <mailhol.vincent@wanadoo.fr>2021-01-20 20:41:36 +0900
committerMarc Kleine-Budde <mkl@pengutronix.de>2021-01-20 13:33:12 +0100
commit75854cad5d80976f6ea0f0431f8cedd3bcc475cb (patch)
tree04e4b19da43954395aca5a3ae98db7bf8fee86c3 /drivers/net/can
parent03f16c5075b22c8902d2af739969e878b0879c94 (diff)
can: vxcan: vxcan_xmit: fix use after free bug
After calling netif_rx_ni(skb), dereferencing skb is unsafe. Especially, the canfd_frame cfd which aliases skb memory is accessed after the netif_rx_ni(). Fixes: a8f820a380a2 ("can: add Virtual CAN Tunnel driver (vxcan)") Link: https://lore.kernel.org/r/20210120114137.200019-3-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'drivers/net/can')
-rw-r--r--drivers/net/can/vxcan.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/net/can/vxcan.c b/drivers/net/can/vxcan.c
index fa47bab510bb..f9a524c5f6d6 100644
--- a/drivers/net/can/vxcan.c
+++ b/drivers/net/can/vxcan.c
@@ -39,6 +39,7 @@ static netdev_tx_t vxcan_xmit(struct sk_buff *skb, struct net_device *dev)
struct net_device *peer;
struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
struct net_device_stats *peerstats, *srcstats = &dev->stats;
+ u8 len;
if (can_dropped_invalid_skb(dev, skb))
return NETDEV_TX_OK;
@@ -61,12 +62,13 @@ static netdev_tx_t vxcan_xmit(struct sk_buff *skb, struct net_device *dev)
skb->dev = peer;
skb->ip_summed = CHECKSUM_UNNECESSARY;
+ len = cfd->len;
if (netif_rx_ni(skb) == NET_RX_SUCCESS) {
srcstats->tx_packets++;
- srcstats->tx_bytes += cfd->len;
+ srcstats->tx_bytes += len;
peerstats = &peer->stats;
peerstats->rx_packets++;
- peerstats->rx_bytes += cfd->len;
+ peerstats->rx_bytes += len;
}
out_unlock: