FAILED: patch "[PATCH] cpufreq: governor: fix double free in" failed to apply to 5.15-stable tree

FAILED: patch "[PATCH] cpufreq: governor: fix double free in" failed to apply to 5.15-stable tree

[gregkh]

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 6dcf9d0064ce2f3e3dfe5755f98b93abe6a98e1e
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026040816-flattop-footing-328d@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 6dcf9d0064ce2f3e3dfe5755f98b93abe6a98e1e Mon Sep 17 00:00:00 2001
From: Guangshuo Li <lgs201920130244@gmail.com>
Date: Wed, 1 Apr 2026 10:45:35 +0800
Subject: [PATCH] cpufreq: governor: fix double free in
 cpufreq_dbs_governor_init() error path

When kobject_init_and_add() fails, cpufreq_dbs_governor_init() calls
kobject_put(&dbs_data->attr_set.kobj).

The kobject release callback cpufreq_dbs_data_release() calls
gov->exit(dbs_data) and kfree(dbs_data), but the current error path
then calls gov->exit(dbs_data) and kfree(dbs_data) again, causing a
double free.

Keep the direct kfree(dbs_data) for the gov->init() failure path, but
after kobject_init_and_add() has been called, let kobject_put() handle
the cleanup through cpufreq_dbs_data_release().

Fixes: 4ebe36c94aed ("cpufreq: Fix kobject memleak")
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
Reviewed-by: Zhongqiu Han <zhongqiu.han@oss.qualcomm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: All applicable <stable@vger.kernel.org>
Link: https://patch.msgid.link/20260401024535.1395801-1-lgs201920130244@gmail.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpufreq/cpufreq_governor.c b/drivers/cpufreq/cpufreq_governor.c
index acf101878733..86f35e451914 100644
--- a/drivers/cpufreq/cpufreq_governor.c
+++ b/drivers/cpufreq/cpufreq_governor.c
@@ -468,13 +468,13 @@ int cpufreq_dbs_governor_init(struct cpufreq_policy *policy)
 	/* Failure, so roll back. */
 	pr_err("initialization failed (dbs_data kobject init error %d)\n", ret);
 
-	kobject_put(&dbs_data->attr_set.kobj);
-
 	policy->governor_data = NULL;
 
 	if (!have_governor_per_policy())
 		gov->gdbs_data = NULL;
-	gov->exit(dbs_data);
+
+	kobject_put(&dbs_data->attr_set.kobj);
+	goto free_policy_dbs_info;
 
 free_dbs_data:
 	kfree(dbs_data);

[PATCH 5.15.y 1/2] cpufreq: governor: Free dbs_data directly when gov->init() fails

[Sasha Levin]

From: Liao Chang <liaochang1@huawei.com>

[ Upstream commit 916f13884042f615cfbfc0b42cc68dadee826f2a ]

Due to the kobject embedded in the dbs_data doest not has a release()
method yet, it needs to use kfree() to free dbs_data directly when
governor fails to allocate the tunner field of dbs_data.

Signed-off-by: Liao Chang <liaochang1@huawei.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Stable-dep-of: 6dcf9d0064ce ("cpufreq: governor: fix double free in cpufreq_dbs_governor_init() error path")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/cpufreq/cpufreq_governor.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/cpufreq/cpufreq_governor.c b/drivers/cpufreq/cpufreq_governor.c
index 5981e3ef9ce0e..3de5a2ca903ea 100644
--- a/drivers/cpufreq/cpufreq_governor.c
+++ b/drivers/cpufreq/cpufreq_governor.c
@@ -440,7 +440,7 @@ int cpufreq_dbs_governor_init(struct cpufreq_policy *policy)
 
 	ret = gov->init(dbs_data);
 	if (ret)
-		goto free_policy_dbs_info;
+		goto free_dbs_data;
 
 	/*
 	 * The sampling interval should not be less than the transition latency
@@ -475,6 +475,8 @@ int cpufreq_dbs_governor_init(struct cpufreq_policy *policy)
 	if (!have_governor_per_policy())
 		gov->gdbs_data = NULL;
 	gov->exit(dbs_data);
+
+free_dbs_data:
 	kfree(dbs_data);
 
 free_policy_dbs_info:
-- 
2.53.0

[PATCH 5.15.y 2/2] cpufreq: governor: fix double free in cpufreq_dbs_governor_init() error path

[Sasha Levin]

From: Guangshuo Li <lgs201920130244@gmail.com>

[ Upstream commit 6dcf9d0064ce2f3e3dfe5755f98b93abe6a98e1e ]

When kobject_init_and_add() fails, cpufreq_dbs_governor_init() calls
kobject_put(&dbs_data->attr_set.kobj).

The kobject release callback cpufreq_dbs_data_release() calls
gov->exit(dbs_data) and kfree(dbs_data), but the current error path
then calls gov->exit(dbs_data) and kfree(dbs_data) again, causing a
double free.

Keep the direct kfree(dbs_data) for the gov->init() failure path, but
after kobject_init_and_add() has been called, let kobject_put() handle
the cleanup through cpufreq_dbs_data_release().

Fixes: 4ebe36c94aed ("cpufreq: Fix kobject memleak")
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
Reviewed-by: Zhongqiu Han <zhongqiu.han@oss.qualcomm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: All applicable <stable@vger.kernel.org>
Link: https://patch.msgid.link/20260401024535.1395801-1-lgs201920130244@gmail.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/cpufreq/cpufreq_governor.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/cpufreq/cpufreq_governor.c b/drivers/cpufreq/cpufreq_governor.c
index 3de5a2ca903ea..76f3fe790f1f8 100644
--- a/drivers/cpufreq/cpufreq_governor.c
+++ b/drivers/cpufreq/cpufreq_governor.c
@@ -468,13 +468,13 @@ int cpufreq_dbs_governor_init(struct cpufreq_policy *policy)
 	/* Failure, so roll back. */
 	pr_err("initialization failed (dbs_data kobject init error %d)\n", ret);
 
-	kobject_put(&dbs_data->attr_set.kobj);
-
 	policy->governor_data = NULL;
 
 	if (!have_governor_per_policy())
 		gov->gdbs_data = NULL;
-	gov->exit(dbs_data);
+
+	kobject_put(&dbs_data->attr_set.kobj);
+	goto free_policy_dbs_info;
 
 free_dbs_data:
 	kfree(dbs_data);
-- 
2.53.0