In mii_nway_restart() during the line:
bmcr = mii->mdio_read(mii->dev, mii->phy_id, MII_BMCR);
The code attempts to call mii->mdio_read which is ch9200_mdio_read().
ch9200_mdio_read() utilises a local buffer, which is initialised
with control_read():
unsigned char buff[2];
However buff is conditionally initialised inside control_read():
if (err == size) {
memcpy(data, buf, size);
}
If the condition of "err == size" is not met, then buff remains
uninitialised. Once this happens the uninitialised buff is accessed
and returned during ch9200_mdio_read():
return (buff[0] | buff[1] << 8);
The problem stems from the fact that ch9200_mdio_read() ignores the
return value of control_read(), leading to uinit-access of buff.
To fix this we should check the return value of control_read()
and return early on error.
Furthermore the get_mac_address() function has a similar problem 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.
Lastly ch9200_bind() ignores the return values of multiple
control_write() calls.
Validate each control_write() call to ensure it succeeds before
continuing with the next call.
Reported-by: syzbot <syzbot+3361c2d6f78a3e0892f9@xxxxxxxxxxxxxxxxxxxxxxxxx>
Closes: https://syzkaller.appspot.com/bug?extid=3361c2d6f78a3e0892f9
Tested-by: syzbot <syzbot+3361c2d6f78a3e0892f9@xxxxxxxxxxxxxxxxxxxxxxxxx>
Fixes: 4a476bd6d1d9 ("usbnet: New driver for QinHeng CH9200 devices")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Qasim Ijaz <qasdev00@xxxxxxxxx>
---
drivers/net/mii.c | 2 ++
drivers/net/usb/ch9200.c | 55 +++++++++++++++++++++++++++-------------
2 files changed, 40 insertions(+), 17 deletions(-)
diff --git a/drivers/net/mii.c b/drivers/net/mii.c
index 37bc3131d31a..e305bf0f1d04 100644
--- a/drivers/net/mii.c
+++ b/drivers/net/mii.c
@@ -464,6 +464,8 @@ int mii_nway_restart (struct mii_if_info *mii)
/* if autoneg is off, it's an error */
bmcr = mii->mdio_read(mii->dev, mii->phy_id, MII_BMCR);
+ if (bmcr < 0)
+ return bmcr;
if (bmcr & BMCR_ANENABLE) {
bmcr |= BMCR_ANRESTART;
diff --git a/drivers/net/usb/ch9200.c b/drivers/net/usb/ch9200.c
index f69d9b902da0..e938501a1fc8 100644
--- a/drivers/net/usb/ch9200.c
+++ b/drivers/net/usb/ch9200.c
@@ -178,6 +178,7 @@ static int ch9200_mdio_read(struct net_device *netdev, int phy_id, int loc)
{
struct usbnet *dev = netdev_priv(netdev);
unsigned char buff[2];
+ int ret;
netdev_dbg(netdev, "%s phy_id:%02x loc:%02x\n",
__func__, phy_id, loc);
@@ -185,8 +186,10 @@ static int ch9200_mdio_read(struct net_device *netdev, int phy_id, int loc)
if (phy_id != 0)
return -ENODEV;
- control_read(dev, REQUEST_READ, 0, loc * 2, buff, 0x02,
- CONTROL_TIMEOUT_MS);
+ ret = control_read(dev, REQUEST_READ, 0, loc * 2, buff, 0x02,
+ CONTROL_TIMEOUT_MS);
+ if (ret != 2)
+ return ret;
return (buff[0] | buff[1] << 8);
}
@@ -303,24 +306,27 @@ 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 != 2)
+ 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 != 2)
+ 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 != 2)
+ return rd_mac_len;
data[0] = mac_addr[5];
data[1] = mac_addr[4];
@@ -329,12 +335,12 @@ 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)
{
- int retval = 0;
+ int retval;
unsigned char data[2];
u8 addr[ETH_ALEN];
@@ -357,37 +363,52 @@ static int ch9200_bind(struct usbnet *dev, struct usb_interface *intf)
data[1] = 0x0F;
retval = control_write(dev, REQUEST_WRITE, 0, MAC_REG_THRESHOLD, data,
0x02, CONTROL_TIMEOUT_MS);
+ if (retval)
+ return retval;
data[0] = 0xA0;
data[1] = 0x90;
retval = control_write(dev, REQUEST_WRITE, 0, MAC_REG_FIFO_DEPTH, data,
0x02, CONTROL_TIMEOUT_MS);
+ if (retval)
+ return retval;
data[0] = 0x30;
data[1] = 0x00;
retval = control_write(dev, REQUEST_WRITE, 0, MAC_REG_PAUSE, data,
0x02, CONTROL_TIMEOUT_MS);
+ if (retval)
+ return retval;
data[0] = 0x17;
data[1] = 0xD8;
retval = control_write(dev, REQUEST_WRITE, 0, MAC_REG_FLOW_CONTROL,
data, 0x02, CONTROL_TIMEOUT_MS);
+ if (retval)
+ return retval;
/* Undocumented register */
data[0] = 0x01;
data[1] = 0x00;
retval = control_write(dev, REQUEST_WRITE, 0, 254, data, 0x02,
CONTROL_TIMEOUT_MS);
+ if (retval)
+ return retval;
data[0] = 0x5F;
data[1] = 0x0D;
retval = control_write(dev, REQUEST_WRITE, 0, MAC_REG_CTRL, data, 0x02,
CONTROL_TIMEOUT_MS);
+ if (retval)
+ return retval;
retval = get_mac_address(dev, addr);
+ if (retval)
+ return retval;
+
eth_hw_addr_set(dev->net, addr);
- return retval;
+ return 0;
}
static const struct driver_info ch9200_info = {
--
2.39.5
