This is a note to let you know that I've just added the patch titled
cpufreq: CPPC: Fix wrong return value in cppc_get_cpu_cost()
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
cpufreq-cppc-fix-wrong-return-value-in-cppc_get_cpu_.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit c525ce903f12d2f6dd6dc69f0d2febc7bf8bd592
Author: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
Date: Wed Nov 6 09:12:38 2024 +0800
cpufreq: CPPC: Fix wrong return value in cppc_get_cpu_cost()
[ Upstream commit be392aa80f1e5b0b65ccc2a540b9304fefcfe3d8 ]
cppc_get_cpu_cost() return 0 if the policy is NULL. Then in
em_compute_costs(), the later zero check for cost is not valid
as cost is uninitialized. As Quentin pointed out, kernel energy model
core check the return value of get_cost() first, so if the callback
failed it should tell the core. Return -EINVAL to fix it.
Fixes: 1a1374bb8c59 ("cpufreq: CPPC: Fix possible null-ptr-deref for cppc_get_cpu_cost()")
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Closes: https://lore.kernel.org/all/c4765377-7830-44c2-84fa-706b6e304e10@stanley.mountain/
Signed-off-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
Suggested-by: Quentin Perret <qperret@xxxxxxxxxx>
Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
index 0a2c21d5bc1c8..fd02702de504c 100644
--- a/drivers/cpufreq/cppc_cpufreq.c
+++ b/drivers/cpufreq/cppc_cpufreq.c
@@ -493,7 +493,7 @@ static int cppc_get_cpu_cost(struct device *cpu_dev, unsigned long KHz,
policy = cpufreq_cpu_get_raw(cpu_dev->id);
if (!policy)
- return 0;
+ return -EINVAL;
cpu_data = policy->driver_data;
perf_caps = &cpu_data->perf_caps;
