From: Yang Yingliang <yangyingliang@huawei.com>
Date: Sat, 19 Nov 2022 16:11:34 +0800
Patch-mainline: v6.1-rc7
Subject: Drivers: hv: vmbus: fix double free in the error path of vmbus_add_channel_work()
Git-commit: f92a4b50f0bd7fd52391dc4bb9a309085d278f91
References: git-fixes
In the error path of vmbus_device_register(), device_unregister()
is called, which calls vmbus_device_release(). The latter frees
the struct hv_device that was passed in to vmbus_device_register().
So remove the kfree() in vmbus_add_channel_work() to avoid a double
free.
Fixes: c2e5df616e1a ("vmbus: add per-channel sysfs info")
Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20221119081135.1564691-2-yangyingliang@huawei.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Acked-by: Olaf Hering <ohering@suse.de>
---
drivers/hv/channel_mgmt.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -533,13 +533,17 @@ static void vmbus_add_channel_work(struct work_struct *work)
* Add the new device to the bus. This will kick off device-driver
* binding which eventually invokes the device driver's AddDevice()
* method.
+ *
+ * If vmbus_device_register() fails, the 'device_obj' is freed in
+ * vmbus_device_release() as called by device_unregister() in the
+ * error path of vmbus_device_register(). In the outside error
+ * path, there's no need to free it.
*/
ret = vmbus_device_register(newchannel->device_obj);
if (ret != 0) {
pr_err("unable to add child device object (relid %d)\n",
newchannel->offermsg.child_relid);
- kfree(newchannel->device_obj);
goto err_deq_chan;
}