From 169e979c0b037a1d94e14cde238b9853fcc985f8 Mon Sep 17 00:00:00 2001 From: Nathan Lynch Date: Fri, 7 Jun 2019 00:04:07 -0500 Subject: [PATCH] powerpc/pseries: Fix oops in hotplug memory notifier commit 0aa82c482ab2ece530a6f44897b63b274bb43c8e upstream. 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. Fixes: 2b31e3aec1db ("powerpc/drmem: Add support for ibm, dynamic-memory-v2 property") Cc: stable@vger.kernel.org # v4.16+ Signed-off-by: Nathan Lynch Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman --- 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 47087832f8b2e..e6bd172bcf305 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; -- 2.39.2