[PATCH] powerpc/pseries: fix oops in hotplug memory notifier

[Nathan Lynch]

Michael Ellerman <mpe at ellerman.id.au> writes:

> Nathan Lynch <nathanl at linux.ibm.com> writes:
>
>> During post-migration device tree updates, we can oops in
>> pseries_update_drconf_memory if the source device tree has an
>> ibm,dynamic-memory-v2 property and the destination has a
>> ibm,dynamic_memory (v1) property. The notifier processes an "update"
>> for the ibm,dynamic-memory property but it's really an add in this
>> scenario. So make sure the old property object is there before
>> dereferencing it.
>>
>> Signed-off-by: Nathan Lynch <nathanl at linux.ibm.com>
>
> Can you pinpoint a commit that introduced the bug? Should we backport
> this to stable?
>
> Perhaps?
>   Fixes: 2b31e3aec1db ("powerpc/drmem: Add support for ibm, dynamic-memory-v2 property")

I guess I had considered it a latent bug, but you're right - we wouldn't
hit it until the v2 support was added. So that commit is correct. Let me
know if I should resend.