This is a note to let you know that I've just added the patch titled
Drivers: hv: vmbus: fix double free in the error path of vmbus_add_channel_work()
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drivers-hv-vmbus-fix-double-free-in-the-error-path-o.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 80b5df01ca538aa0718717a33f880e47c5c5ad19
Author: Yang Yingliang <yangyingliang@xxxxxxxxxx>
Date: Sat Nov 19 16:11:34 2022 +0800
Drivers: hv: vmbus: fix double free in the error path of vmbus_add_channel_work()
[ Upstream commit f92a4b50f0bd7fd52391dc4bb9a309085d278f91 ]
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@xxxxxxxxxxxxx>
Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx>
Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20221119081135.1564691-2-yangyingliang@xxxxxxxxxx
Signed-off-by: Wei Liu <wei.liu@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index a3f6933f94e3..ccfa5ceb43c0 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -508,13 +508,17 @@ 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;
}
