From: Miaoqian Lin <linmq006@gmail.com>
Date: Thu, 28 Aug 2025 07:00:51 +0000 (+0800)
Subject: um: virtio_uml: Fix use-after-free after put_device in probe
X-Git-Tag: v6.12.49~97
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=00e98b5a69034b251bb36dc6e7123d7648e218e4;p=thirdparty%2Fkernel%2Fstable.git

um: virtio_uml: Fix use-after-free after put_device in probe

[ Upstream commit 7ebf70cf181651fe3f2e44e95e7e5073d594c9c0 ]

When register_virtio_device() fails in virtio_uml_probe(),
the code sets vu_dev->registered = 1 even though
the device was not successfully registered.
This can lead to use-after-free or other issues.

Fixes: 04e5b1fb0183 ("um: virtio: Remove device on disconnect")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/arch/um/drivers/virtio_uml.c b/arch/um/drivers/virtio_uml.c
index 2b6e701776b6b..e2cba5117fd25 100644
--- a/arch/um/drivers/virtio_uml.c
+++ b/arch/um/drivers/virtio_uml.c
@@ -1231,10 +1231,12 @@ static int virtio_uml_probe(struct platform_device *pdev)
 	device_set_wakeup_capable(&vu_dev->vdev.dev, true);
 
 	rc = register_virtio_device(&vu_dev->vdev);
-	if (rc)
+	if (rc) {
 		put_device(&vu_dev->vdev.dev);
+		return rc;
+	}
 	vu_dev->registered = 1;
-	return rc;
+	return 0;
 
 error_init:
 	os_close_file(vu_dev->sock);