From: Dan Carpenter dan.carpenter@oracle.com
[ Upstream commit a6921dd524fe31d1f460c161d3526a407533b6db ]
These values come from skb->data so Smatch considers them untrusted. I believe Smatch is correct but I don't have a way to test this.
The usb_if->dev[] array has 2 elements but the index is in the 0-15 range without checks. The cfd->len can be up to 255 but the maximum valid size is CANFD_MAX_DLEN (64) so that could lead to memory corruption.
Fixes: 0a25e1f4f185 ("can: peak_usb: add support for PEAK new CANFD USB adapters") Signed-off-by: Dan Carpenter dan.carpenter@oracle.com Link: https://lore.kernel.org/r/20200813140604.GA456946@mwanda Acked-by: Stephane Grosjean s.grosjean@peak-system.com Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/can/usb/peak_usb/pcan_usb_fd.c | 48 +++++++++++++++++----- 1 file changed, 37 insertions(+), 11 deletions(-)
diff --git a/drivers/net/can/usb/peak_usb/pcan_usb_fd.c b/drivers/net/can/usb/peak_usb/pcan_usb_fd.c index 41988358f63c8..19600d35aac55 100644 --- a/drivers/net/can/usb/peak_usb/pcan_usb_fd.c +++ b/drivers/net/can/usb/peak_usb/pcan_usb_fd.c @@ -476,12 +476,18 @@ static int pcan_usb_fd_decode_canmsg(struct pcan_usb_fd_if *usb_if, struct pucan_msg *rx_msg) { struct pucan_rx_msg *rm = (struct pucan_rx_msg *)rx_msg; - struct peak_usb_device *dev = usb_if->dev[pucan_msg_get_channel(rm)]; - struct net_device *netdev = dev->netdev; + struct peak_usb_device *dev; + struct net_device *netdev; struct canfd_frame *cfd; struct sk_buff *skb; const u16 rx_msg_flags = le16_to_cpu(rm->flags);
+ if (pucan_msg_get_channel(rm) >= ARRAY_SIZE(usb_if->dev)) + return -ENOMEM; + + dev = usb_if->dev[pucan_msg_get_channel(rm)]; + netdev = dev->netdev; + if (rx_msg_flags & PUCAN_MSG_EXT_DATA_LEN) { /* CANFD frame case */ skb = alloc_canfd_skb(netdev, &cfd); @@ -527,15 +533,21 @@ static int pcan_usb_fd_decode_status(struct pcan_usb_fd_if *usb_if, struct pucan_msg *rx_msg) { struct pucan_status_msg *sm = (struct pucan_status_msg *)rx_msg; - struct peak_usb_device *dev = usb_if->dev[pucan_stmsg_get_channel(sm)]; - struct pcan_usb_fd_device *pdev = - container_of(dev, struct pcan_usb_fd_device, dev); + struct pcan_usb_fd_device *pdev; enum can_state new_state = CAN_STATE_ERROR_ACTIVE; enum can_state rx_state, tx_state; - struct net_device *netdev = dev->netdev; + struct peak_usb_device *dev; + struct net_device *netdev; struct can_frame *cf; struct sk_buff *skb;
+ if (pucan_stmsg_get_channel(sm) >= ARRAY_SIZE(usb_if->dev)) + return -ENOMEM; + + dev = usb_if->dev[pucan_stmsg_get_channel(sm)]; + pdev = container_of(dev, struct pcan_usb_fd_device, dev); + netdev = dev->netdev; + /* nothing should be sent while in BUS_OFF state */ if (dev->can.state == CAN_STATE_BUS_OFF) return 0; @@ -587,9 +599,14 @@ static int pcan_usb_fd_decode_error(struct pcan_usb_fd_if *usb_if, struct pucan_msg *rx_msg) { struct pucan_error_msg *er = (struct pucan_error_msg *)rx_msg; - struct peak_usb_device *dev = usb_if->dev[pucan_ermsg_get_channel(er)]; - struct pcan_usb_fd_device *pdev = - container_of(dev, struct pcan_usb_fd_device, dev); + struct pcan_usb_fd_device *pdev; + struct peak_usb_device *dev; + + if (pucan_ermsg_get_channel(er) >= ARRAY_SIZE(usb_if->dev)) + return -EINVAL; + + dev = usb_if->dev[pucan_ermsg_get_channel(er)]; + pdev = container_of(dev, struct pcan_usb_fd_device, dev);
/* keep a trace of tx and rx error counters for later use */ pdev->bec.txerr = er->tx_err_cnt; @@ -603,11 +620,17 @@ static int pcan_usb_fd_decode_overrun(struct pcan_usb_fd_if *usb_if, struct pucan_msg *rx_msg) { struct pcan_ufd_ovr_msg *ov = (struct pcan_ufd_ovr_msg *)rx_msg; - struct peak_usb_device *dev = usb_if->dev[pufd_omsg_get_channel(ov)]; - struct net_device *netdev = dev->netdev; + struct peak_usb_device *dev; + struct net_device *netdev; struct can_frame *cf; struct sk_buff *skb;
+ if (pufd_omsg_get_channel(ov) >= ARRAY_SIZE(usb_if->dev)) + return -EINVAL; + + dev = usb_if->dev[pufd_omsg_get_channel(ov)]; + netdev = dev->netdev; + /* allocate an skb to store the error frame */ skb = alloc_can_err_skb(netdev, &cf); if (!skb) @@ -724,6 +747,9 @@ static int pcan_usb_fd_encode_msg(struct peak_usb_device *dev, u16 tx_msg_size, tx_msg_flags; u8 can_dlc;
+ if (cfd->len > CANFD_MAX_DLEN) + return -EINVAL; + tx_msg_size = ALIGN(sizeof(struct pucan_tx_msg) + cfd->len, 4); tx_msg->size = cpu_to_le16(tx_msg_size); tx_msg->type = cpu_to_le16(PUCAN_MSG_CAN_TX);