Re: [PATCH v1] drivers/base/memory: add memory block to memory group after registration succeeded

On 01.02.22 02:01, Andrew Morton wrote:

On Fri, 28 Jan 2022 15:45:40 +0100 David Hildenbrand david@redhat.com wrote:

...

If register_memory() fails, we freed the memory block but already added the memory block to the group list, not good. Let's defer adding the block to the memory group to after registering the memory block device.

We do handle it properly during unregister_memory(), but that's not called when the registration fails.

I guess this has never been known to happen. So I queued the fix for 5.18-rc1, cc:stable.

Triggering that registration error is fairly hard, usually we fail memory hotplug because we fail to allocate the (largish) memmap. So I am not aware that this BUG actually triggered.