Commit 78bb5d20 authored by Aleksandr Mishin's avatar Aleksandr Mishin Committed by Liu Mingrui
Browse files

cppc_cpufreq: Fix possible null pointer dereference 

stable inclusion
from stable-v6.6.33
commit f84b9b25d045e67a7eee5e73f21278c8ab06713c
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IA74DQ

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f84b9b25d045e67a7eee5e73f21278c8ab06713c



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[ Upstream commit cf7de25878a1f4508c69dc9f6819c21ba177dbfe ]

cppc_cpufreq_get_rate() and hisi_cppc_cpufreq_get_rate() can be called from
different places with various parameters. So cpufreq_cpu_get() can return
null as 'policy' in some circumstances.
Fix this bug by adding null return check.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: a28b2bfc ("cppc_cpufreq: replace per-cpu data array with a list")
Signed-off-by: default avatarAleksandr Mishin <amishin@t-argos.ru>
Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>

Conflicts:
	drivers/cpufreq/cppc_cpufreq.c
[Context conflict]
Signed-off-by: default avatarZhangPeng <zhangpeng362@huawei.com>
Signed-off-by: default avatarLiu Mingrui <liumingrui@huawei.com>
parent 1f027a60

drivers/cpufreq/cppc_cpufreq.c

+12 −2
Original line number Diff line number Diff line
@@ -878,10 +878,15 @@ static unsigned int cppc_cpufreq_get_rate(unsigned int cpu) 
{

	struct fb_ctr_pair fb_ctrs = { .cpu = cpu, };

	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);

	struct cppc_cpudata *cpu_data = policy->driver_data;

	struct cppc_cpudata *cpu_data;

	u64 delivered_perf;

	int ret;



	if (!policy)

		return -ENODEV;



	cpu_data = policy->driver_data;



	cpufreq_cpu_put(policy);



	if (cpu_has_amu_feat(cpu))
@@ -961,10 +966,15 @@ static struct cpufreq_driver cppc_cpufreq_driver = { 
static unsigned int hisi_cppc_cpufreq_get_rate(unsigned int cpu)

{

	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);

	struct cppc_cpudata *cpu_data = policy->driver_data;

	struct cppc_cpudata *cpu_data;

	u64 desired_perf;

	int ret;



	if (!policy)

		return -ENODEV;



	cpu_data = policy->driver_data;



	cpufreq_cpu_put(policy);



	ret = cppc_get_desired_perf(cpu, &desired_perf);