[PATCH QEMU HCI-8.0 v4 01/12] usb-host: don't leak hostdev FD on open failure #VSTOR-137800

[Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>]

The FD passed into usb_host_open() for a wrapped device is only stored in
s->hostfd after libusb_wrap_sys_device() succeeds, and the failure path
doesn't close it.  if wrapping fails, or a later step of the open sequence
fails (e.g. usb_device_attach), the FD is leaked, as usb_host_close() only
runs for fully opened devices, and the realize error path doesn't clean it
up either.

Store the FD in s->hostfd before wrapping and close it on the failure
path.

Signed-off-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>
---
 hw/usb/host-libusb.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/hw/usb/host-libusb.c b/hw/usb/host-libusb.c
index b74670ae256..83645fbe0ce 100644
--- a/hw/usb/host-libusb.c
+++ b/hw/usb/host-libusb.c
@@ -954,6 +954,11 @@ static int usb_host_open(USBHostDevice *s, libusb_device *dev, int hostfd)
     int rc;
     Error *local_err = NULL;
 
+    /* Make sure failure path frees caller-owned FD */
+    if (!dev) {
+        s->hostfd = hostfd;
+    }
+
     if (s->bh_postld_pending) {
         return -1;
     }
@@ -978,7 +983,6 @@ static int usb_host_open(USBHostDevice *s, libusb_device *dev, int hostfd)
         if (rc != 0) {
             goto fail;
         }
-        s->hostfd  = hostfd;
         dev = libusb_get_device(s->dh);
         bus_num = libusb_get_bus_number(dev);
         addr = libusb_get_device_address(dev);
@@ -1066,6 +1070,10 @@ fail:
         s->dh = NULL;
         s->dev = NULL;
     }
+    if (s->hostfd != -1) {
+        close(s->hostfd);
+        s->hostfd = -1;
+    }
     return -1;
 }
 

-- 
2.47.1