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 <nath...@linux.ibm.com> --- arch/powerpc/platforms/pseries/hotplug-memory.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c index 47087832f8b2..e6bd172bcf30 100644 --- a/arch/powerpc/platforms/pseries/hotplug-memory.c +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c @@ -980,6 +980,9 @@ static int pseries_update_drconf_memory(struct of_reconfig_data *pr) if (!memblock_size) return -EINVAL; + if (!pr->old_prop) + return 0; + p = (__be32 *) pr->old_prop->value; if (!p) return -EINVAL; -- 2.20.1