linux-kernel - [PATCH] cpufreq: CPPC: Fix possible null-ptr-deref for cppc_get_cpu

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20241030082449.2629861-1-ruanjinjie@huawei.com>
Date: Wed, 30 Oct 2024 16:24:49 +0800
From: Jinjie Ruan <ruanjinjie@...wei.com>
To: <rafael@...nel.org>, <viresh.kumar@...aro.org>, <Pierre.Gondois@....com>,
	<linux-pm@...r.kernel.org>, <linux-kernel@...r.kernel.org>
CC: <ruanjinjie@...wei.com>
Subject: [PATCH] cpufreq: CPPC: Fix possible null-ptr-deref for cppc_get_cpu_cost()

cpufreq_cpu_get_raw() may return NULL if the cpu is not in
policy->cpus cpu mask and it will cause null pointer dereference,
so check NULL for cppc_get_cpu_cost().

Fixes: 740fcdc2c20e ("cpufreq: CPPC: Register EM based on efficiency class information")
Signed-off-by: Jinjie Ruan <ruanjinjie@...wei.com>
---
 drivers/cpufreq/cppc_cpufreq.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
index 2b8708475ac7..67fa97bbeae7 100644
--- a/drivers/cpufreq/cppc_cpufreq.c
+++ b/drivers/cpufreq/cppc_cpufreq.c
@@ -487,6 +487,9 @@ static int cppc_get_cpu_cost(struct device *cpu_dev, unsigned long KHz,
 	int step;
 
 	policy = cpufreq_cpu_get_raw(cpu_dev->id);
+	if (!policy)
+		return 0;
+
 	cpu_data = policy->driver_data;
 	perf_caps = &cpu_data->perf_caps;
 	max_cap = arch_scale_cpu_capacity(cpu_dev->id);
-- 
2.34.1