The get_mac_address() function has an issue where it does not directly check the return value of each control_read(), instead it sums up the return values and checks them all at the end which means if any call to control_read() fails the function just continues on.
Handle this by validating the return value of each call and fail fast and early instead of continuing.
Fixes: 4a476bd6d1d9 ("usbnet: New driver for QinHeng CH9200 devices") Reviewed-by: Simon Horman horms@kernel.org Signed-off-by: Qasim Ijaz qasdev00@gmail.com --- drivers/net/usb/ch9200.c | 32 +++++++++++++++++++------------- 1 file changed, 19 insertions(+), 13 deletions(-)
diff --git a/drivers/net/usb/ch9200.c b/drivers/net/usb/ch9200.c index 61eb6c207eb1..4f1d2e9045a9 100644 --- a/drivers/net/usb/ch9200.c +++ b/drivers/net/usb/ch9200.c @@ -304,24 +304,27 @@ static int ch9200_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
static int get_mac_address(struct usbnet *dev, unsigned char *data) { - int err = 0; unsigned char mac_addr[0x06]; - int rd_mac_len = 0; + int rd_mac_len;
netdev_dbg(dev->net, "%s:\n\tusbnet VID:%0x PID:%0x\n", __func__, le16_to_cpu(dev->udev->descriptor.idVendor), le16_to_cpu(dev->udev->descriptor.idProduct));
- memset(mac_addr, 0, sizeof(mac_addr)); - rd_mac_len = control_read(dev, REQUEST_READ, 0, - MAC_REG_STATION_L, mac_addr, 0x02, - CONTROL_TIMEOUT_MS); - rd_mac_len += control_read(dev, REQUEST_READ, 0, MAC_REG_STATION_M, - mac_addr + 2, 0x02, CONTROL_TIMEOUT_MS); - rd_mac_len += control_read(dev, REQUEST_READ, 0, MAC_REG_STATION_H, - mac_addr + 4, 0x02, CONTROL_TIMEOUT_MS); - if (rd_mac_len != ETH_ALEN) - err = -EINVAL; + rd_mac_len = control_read(dev, REQUEST_READ, 0, MAC_REG_STATION_L, + mac_addr, 0x02, CONTROL_TIMEOUT_MS); + if (rd_mac_len < 0) + return rd_mac_len; + + rd_mac_len = control_read(dev, REQUEST_READ, 0, MAC_REG_STATION_M, + mac_addr + 2, 0x02, CONTROL_TIMEOUT_MS); + if (rd_mac_len < 0) + return rd_mac_len; + + rd_mac_len = control_read(dev, REQUEST_READ, 0, MAC_REG_STATION_H, + mac_addr + 4, 0x02, CONTROL_TIMEOUT_MS); + if (rd_mac_len < 0) + return rd_mac_len;
data[0] = mac_addr[5]; data[1] = mac_addr[4]; @@ -330,7 +333,7 @@ static int get_mac_address(struct usbnet *dev, unsigned char *data) data[4] = mac_addr[1]; data[5] = mac_addr[0];
- return err; + return 0; }
static int ch9200_bind(struct usbnet *dev, struct usb_interface *intf) @@ -386,6 +389,9 @@ static int ch9200_bind(struct usbnet *dev, struct usb_interface *intf) CONTROL_TIMEOUT_MS);
retval = get_mac_address(dev, addr); + if (retval < 0) + return retval; + eth_hw_addr_set(dev->net, addr);
return retval;