can: vxcan: vxcan_xmit: fix use after free bug
[ Upstream commit5.4-rM2-2.2.x-imx-squashed75854cad5d
] 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:a8f820a380
("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>
parent
ac48ef1582
commit
a24476b371
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@ -39,6 +39,7 @@ static netdev_tx_t vxcan_xmit(struct sk_buff *skb, struct net_device *dev)
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struct net_device *peer;
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struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
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struct net_device_stats *peerstats, *srcstats = &dev->stats;
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u8 len;
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if (can_dropped_invalid_skb(dev, skb))
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return NETDEV_TX_OK;
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@ -61,12 +62,13 @@ static netdev_tx_t vxcan_xmit(struct sk_buff *skb, struct net_device *dev)
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skb->dev = peer;
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skb->ip_summed = CHECKSUM_UNNECESSARY;
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len = cfd->len;
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if (netif_rx_ni(skb) == NET_RX_SUCCESS) {
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srcstats->tx_packets++;
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srcstats->tx_bytes += cfd->len;
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srcstats->tx_bytes += len;
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peerstats = &peer->stats;
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peerstats->rx_packets++;
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peerstats->rx_bytes += cfd->len;
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peerstats->rx_bytes += len;
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}
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out_unlock:
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