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 5.10-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-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 6025421ca85abab7f2086cea90628aeafc70e1a3 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 10188b1a6a08..5b902adb0d1b 100644 --- a/drivers/hv/channel_mgmt.c +++ b/drivers/hv/channel_mgmt.c @@ -501,13 +501,17 @@ 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; }