[PATCH] usbip: add NULL check for calloc in usbip_exported_device_new

[longlong yan <yanlonglong@kylinos.cn>]

Add a NULL check for the return value of calloc() in
usbip_exported_device_new(). If calloc() fails and returns NULL,
the subsequent dereference of edev->sudev would cause a NULL
pointer dereference.

Also fix the error path at the 'err' label to check edev before
dereferencing edev->sudev. Without this fix, if calloc() fails and
jumps to 'err', the code would dereference NULL when checking
edev->sudev.

Signed-off-by: longlong yan <yanlonglong@kylinos.cn>
---
 tools/usb/usbip/libsrc/usbip_host_common.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tools/usb/usbip/libsrc/usbip_host_common.c b/tools/usb/usbip/libsrc/usbip_host_common.c
index 01599cb2fa7b..94762bc282eb 100644
--- a/tools/usb/usbip/libsrc/usbip_host_common.c
+++ b/tools/usb/usbip/libsrc/usbip_host_common.c
@@ -71,6 +71,8 @@ struct usbip_exported_device *usbip_exported_device_new(
 	int i;
 
 	edev = calloc(1, sizeof(struct usbip_exported_device));
+	if (!edev)
+		goto err;
 
 	edev->sudev =
 		udev_device_new_from_syspath(udev_context, sdevpath);
@@ -107,7 +109,7 @@ struct usbip_exported_device *usbip_exported_device_new(
 
 	return edev;
 err:
-	if (edev->sudev)
+	if (edev && edev->sudev)
 		udev_device_unref(edev->sudev);
 	if (edev)
 		free(edev);
-- 
2.43.0