linux-kernel - [PATCH v2] cpufreq/longhaul: handle NULL policy in longhaul

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Message-ID: <20250830144431.159893-1-nanovim@gmail.com>
Date: Sat, 30 Aug 2025 16:43:59 +0200
From: Dennis Beier <nanovim@...il.com>
To: rafael@...nel.org,
	viresh.kumar@...aro.org
Cc: linux-pm@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Dennis Beier <nanovim@...il.com>
Subject: [PATCH v2] cpufreq/longhaul: handle NULL policy in longhaul_exit

longhaul_exit() was calling cpufreq_cpu_get(0) without checking
for a NULL policy pointer. On some systems, this could lead to a
NULL dereference and a kernel warning or panic.

This patch adds a check using unlikely() and returns early if the
policy is NULL.

Bugzilla: #219962

Signed-off-by: Dennis Beier <nanovim@...il.com>
---
 drivers/cpufreq/longhaul.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/cpufreq/longhaul.c b/drivers/cpufreq/longhaul.c
index ba0e08c8486a..49e76b44468a 100644
--- a/drivers/cpufreq/longhaul.c
+++ b/drivers/cpufreq/longhaul.c
@@ -953,6 +953,9 @@ static void __exit longhaul_exit(void)
 	struct cpufreq_policy *policy = cpufreq_cpu_get(0);
 	int i;
 
+	if (unlikely(!policy))
+		return;
+
 	for (i = 0; i < numscales; i++) {
 		if (mults[i] == maxmult) {
 			struct cpufreq_freqs freqs;
-- 
2.51.0