From: Zhang Rui <rui.zhang@intel.com>
Date: Wed, 31 Jan 2024 11:37:08 +0000 (+0800)
Subject: powercap: intel_rapl: Fix a NULL pointer dereference
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=2d1f5006ff95770da502f8cee2a224a1ff83866e;p=linux.git

powercap: intel_rapl: Fix a NULL pointer dereference

A NULL pointer dereference is triggered when probing the MMIO RAPL
driver on platforms with CPU ID not listed in intel_rapl_common CPU
model list.

This is because the intel_rapl_common module still probes on such
platforms even if 'defaults_msr' is not set after commit 1488ac990ac8
("powercap: intel_rapl: Allow probing without CPUID match"). Thus the
MMIO RAPL rp->priv->defaults is NULL when registering to RAPL framework.

Fix the problem by adding sanity check to ensure rp->priv->rapl_defaults
is always valid.

Fixes: 1488ac990ac8 ("powercap: intel_rapl: Allow probing without CPUID match")
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Cc: 6.5+ <stable@vger.kernel.org> # 6.5+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---

diff --git a/drivers/powercap/intel_rapl_common.c b/drivers/powercap/intel_rapl_common.c
index 2feed036c1cd4..1a739afd47d96 100644
--- a/drivers/powercap/intel_rapl_common.c
+++ b/drivers/powercap/intel_rapl_common.c
@@ -759,6 +759,11 @@ static int rapl_config(struct rapl_package *rp)
 	default:
 		return -EINVAL;
 	}
+
+	/* defaults_msr can be NULL on unsupported platforms */
+	if (!rp->priv->defaults || !rp->priv->rpi)
+		return -ENODEV;
+
 	return 0;
 }