This is a note to let you know that I've just added the patch titled cpufreq: CPPC: Fix possible null-ptr-deref for cppc_get_cpu_cost() to the 6.11-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-possible-null-ptr-deref-for-cppc_ge.patch and it can be found in the queue-6.11 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 015679fea62f23f42e2e8ce91ce2c22e93a7eaf6 Author: Jinjie Ruan <ruanjinjie@xxxxxxxxxx> Date: Wed Oct 30 16:24:49 2024 +0800 cpufreq: CPPC: Fix possible null-ptr-deref for cppc_get_cpu_cost() [ Upstream commit 1a1374bb8c5926674973d849feed500bc61ad535 ] 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@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 32045075c596f..00556b4d83f83 100644 --- a/drivers/cpufreq/cppc_cpufreq.c +++ b/drivers/cpufreq/cppc_cpufreq.c @@ -493,6 +493,9 @@ 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);