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| author | Johan Hovold <johan@kernel.org> | 2020-07-15 11:02:45 +0200 |
|---|---|---|
| committer | Johan Hovold <johan@kernel.org> | 2020-07-16 10:20:21 +0200 |
| commit | e7b931bee739e8a77ae216e613d3b99342b6dec0 (patch) | |
| tree | 12acbe9e68c39c3c42f05159a818c0c3bf994e52 | |
| parent | da6902e5b6dbca9081e3d377f9802d4fd0c5ea59 (diff) | |
| download | mvebu-e7b931bee739e8a77ae216e613d3b99342b6dec0.tar.gz | |
USB: serial: iuu_phoenix: fix memory corruption
The driver would happily overwrite its write buffer with user data in
256 byte increments due to a removed buffer-space sanity check.
Fixes: 5fcf62b0f1f2 ("tty: iuu_phoenix: fix locking.")
Cc: stable <stable@vger.kernel.org> # 2.6.31
Signed-off-by: Johan Hovold <johan@kernel.org>
| -rw-r--r-- | drivers/usb/serial/iuu_phoenix.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/usb/serial/iuu_phoenix.c b/drivers/usb/serial/iuu_phoenix.c index d5bff69b1769b2..b8dfeb4fb2ed6e 100644 --- a/drivers/usb/serial/iuu_phoenix.c +++ b/drivers/usb/serial/iuu_phoenix.c @@ -697,14 +697,16 @@ static int iuu_uart_write(struct tty_struct *tty, struct usb_serial_port *port, struct iuu_private *priv = usb_get_serial_port_data(port); unsigned long flags; - if (count > 256) - return -ENOMEM; - spin_lock_irqsave(&priv->lock, flags); + count = min(count, 256 - priv->writelen); + if (count == 0) + goto out; + /* fill the buffer */ memcpy(priv->writebuf + priv->writelen, buf, count); priv->writelen += count; +out: spin_unlock_irqrestore(&priv->lock, flags); return count; |