usbip: fix vudc to check for stream socket

commit 6801854be94fe8819b3894979875ea31482f5658 upstream.

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/387a670316002324113ac7ea1e8b53f4085d0c95.1615171203.git.skhan@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/usbip/vudc_sysfs.c b/drivers/usb/usbip/vudc_sysfs.c
index 6dcd3ff655c3367cde86919e024b9cc7d174ecec..02e14e596025d7e115813e64194802e33b8b19af 100644 (file)
--- a/drivers/usb/usbip/vudc_sysfs.c
+++ b/drivers/usb/usbip/vudc_sysfs.c
@@ -12,6 +12,7 @@
 #include <linux/usb/ch9.h>
 #include <linux/sysfs.h>
 #include <linux/kthread.h>
+#include <linux/file.h>
 #include <linux/byteorder/generic.h>
 
 #include "usbip_common.h"
@@ -138,6 +139,13 @@ static ssize_t usbip_sockfd_store(struct device *dev, struct device_attribute *a
                        goto unlock_ud;
                }
 
+               if (socket->type != SOCK_STREAM) {
+                       dev_err(dev, "Expecting SOCK_STREAM - found %d",
+                               socket->type);
+                       ret = -EINVAL;
+                       goto sock_err;
+               }
+
                udc->ud.tcp_socket = socket;
 
                spin_unlock_irq(&udc->ud.lock);
@@ -177,6 +185,8 @@ static ssize_t usbip_sockfd_store(struct device *dev, struct device_attribute *a
 
        return count;
 
+sock_err:
+       sockfd_put(socket);
 unlock_ud:
        spin_unlock_irq(&udc->ud.lock);
 unlock: