usbip: fix stub_dev to check for stream socket

Fix usbip_sockfd_store() to validate the passed in file descriptor is
a stream socket. If the file descriptor passed was a SOCK_DGRAM socket,
sock_recvmsg() can't detect end of stream.

Cc: stable@vger.kernel.org
Suggested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lore.kernel.org/r/e942d2bd03afb8e8552bd2a5d84e18d17670d521.1615171203.git.skhan@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/usbip/stub_dev.c b/drivers/usb/usbip/stub_dev.c
index 2305d42..90c1054 100644 (file)
--- a/drivers/usb/usbip/stub_dev.c
+++ b/drivers/usb/usbip/stub_dev.c
@@ -69,8 +69,16 @@ static ssize_t usbip_sockfd_store(struct device *dev, struct device_attribute *a
                }
 
                socket = sockfd_lookup(sockfd, &err);
-               if (!socket)
+               if (!socket) {
+                       dev_err(dev, "failed to lookup sock");
                        goto err;
+               }
+
+               if (socket->type != SOCK_STREAM) {
+                       dev_err(dev, "Expecting SOCK_STREAM - found %d",
+                               socket->type);
+                       goto sock_err;
+               }
 
                sdev->ud.tcp_socket = socket;
                sdev->ud.sockfd = sockfd;
@@ -100,6 +108,8 @@ static ssize_t usbip_sockfd_store(struct device *dev, struct device_attribute *a
 
        return count;
 
+sock_err:
+       sockfd_put(socket);
 err:
        spin_unlock_irq(&sdev->ud.lock);
        return -EINVAL;