* [PATCH v2] cpufreq/longhaul: handle NULL policy in longhaul_exit
@ 2025-08-30 14:43 Dennis Beier
2025-09-01 5:20 ` Viresh Kumar
0 siblings, 1 reply; 2+ messages in thread
From: Dennis Beier @ 2025-08-30 14:43 UTC (permalink / raw)
To: rafael, viresh.kumar; +Cc: linux-pm, linux-kernel, Dennis Beier
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@gmail.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
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v2] cpufreq/longhaul: handle NULL policy in longhaul_exit
2025-08-30 14:43 [PATCH v2] cpufreq/longhaul: handle NULL policy in longhaul_exit Dennis Beier
@ 2025-09-01 5:20 ` Viresh Kumar
0 siblings, 0 replies; 2+ messages in thread
From: Viresh Kumar @ 2025-09-01 5:20 UTC (permalink / raw)
To: Dennis Beier; +Cc: rafael, linux-pm, linux-kernel
On 30-08-25, 16:43, Dennis Beier wrote:
> 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@gmail.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;
Applied. Thanks.
--
viresh
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