diff options
| author | Vincent Mailhol <mailhol.vincent@wanadoo.fr> | 2021-01-20 20:41:36 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-01-27 11:47:48 +0100 |
| commit | a24476b37167816e6352ca1a2cf3769847774f70 (patch) | |
| tree | c4361ebc67d87cb9af817fd680eec71f3b6242bb /drivers | |
| parent | ac48ef15826e83f4206c47add61072e8fc76d328 (diff) | |
can: vxcan: vxcan_xmit: fix use after free bug
[ 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>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/can/vxcan.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/net/can/vxcan.c b/drivers/net/can/vxcan.c index d6ba9426be4d..b1baa4ac1d53 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: |