Re: [PATCH] cpufreq: amd-pstate: add check for cpufreq_cpu_get's return value

From: Mario Limonciello
Date: Tue Jun 04 2024 - 11:57:17 EST


On 6/3/2024 06:07, Anastasia Belova wrote:
cpufreq_cpu_get may return NULL. To avoid NULL-dereference check it
and return in case of error.

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

Signed-off-by: Anastasia Belova <abelova@xxxxxxxxxxxxx>
Thank you!

Acked-by: Mario Limonciello <mario.limonciello@xxxxxxx>

---
drivers/cpufreq/amd-pstate.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 1b7e82a0ad2e..672cb6c280a4 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -621,6 +621,8 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
unsigned long max_perf, min_perf, des_perf,
cap_perf, lowest_nonlinear_perf, max_freq;
struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
+ if (!policy)
+ return;
struct amd_cpudata *cpudata = policy->driver_data;
unsigned int target_freq;
@@ -777,6 +779,8 @@ static void amd_pstate_init_prefcore(struct amd_cpudata *cpudata)
static void amd_pstate_update_limits(unsigned int cpu)
{
struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
+ if (!policy)
+ return;
struct amd_cpudata *cpudata = policy->driver_data;
u32 prev_high = 0, cur_high = 0;
int ret;