From: Vincent Mailhol mailhol.vincent@wanadoo.fr
[ Upstream commit 75854cad5d80976f6ea0f0431f8cedd3bcc475cb ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/can/vxcan.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/net/can/vxcan.c b/drivers/net/can/vxcan.c index ed6828821fbd3..ccd758ba3fb09 100644 --- a/drivers/net/can/vxcan.c +++ b/drivers/net/can/vxcan.c @@ -49,6 +49,7 @@ 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; @@ -71,12 +72,13 @@ 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: