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cppc_cpufreq: Fix possible null pointer dereference

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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: a28b2bfc099c ("cppc_cpufreq: replace per-cpu data array with a list")
Signed-off-by: Aleksandr Mishin <amishin@t-argos.ru>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Aleksandr Mishin 2024-04-08 12:35:36 +03:00 committed by Greg Kroah-Hartman
parent 65cbcec7db
commit 9a185cc5a7
1 changed files with 12 additions and 2 deletions
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14
drivers/cpufreq/cppc_cpufreq.c
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@ -615,10 +615,15 @@ static unsigned int cppc_cpufreq_get_rate(unsigned int cpu)
{
struct cppc_perf_fb_ctrs fb_ctrs_t0 = {0}, fb_ctrs_t1 = {0};
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);
ret = cppc_get_perf_ctrs(cpu, &fb_ctrs_t0);
@ -697,10 +702,15 @@ 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);