[PATCH 6.6 030/396] powercap: intel_rapl: Fix a NULL pointer dereference

Greg Kroah-Hartman
2024-04-01T16:37:51Z

From: Zhang Rui <rui.zhang@intel.com>

[ Upstream commit 2d1f5006ff95770da502f8cee2a224a1ff83866e ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/powercap/intel_rapl_common.c | 5 +++++
1 file changed, 5 insertions(+)

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;
}

--
2.43.0