linux-kernel - [PATCH v13 01/10] power: reset: reboot-mode: Synchronize list traversal

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20250727-arm-psci-system_reset2-vendor-reboots-v13-1-6b8d23315898@oss.qualcomm.com>
Date: Sun, 27 Jul 2025 21:54:44 +0530
From: Shivendra Pratap <shivendra.pratap@....qualcomm.com>
To: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>,
        Bjorn Andersson <andersson@...nel.org>,
        Sebastian Reichel <sre@...nel.org>, Rob Herring <robh@...nel.org>,
        Sudeep Holla <sudeep.holla@....com>,
        Souvik Chakravarty <Souvik.Chakravarty@....com>,
        Krzysztof Kozlowski <krzk+dt@...nel.org>,
        Conor Dooley <conor+dt@...nel.org>, Andy Yan <andy.yan@...k-chips.com>,
        Mark Rutland <mark.rutland@....com>,
        Lorenzo Pieralisi <lpieralisi@...nel.org>,
        Arnd Bergmann <arnd@...db.de>, Konrad Dybcio <konradybcio@...nel.org>,
        cros-qcom-dts-watchers@...omium.org, Vinod Koul <vkoul@...nel.org>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>,
        Florian Fainelli <florian.fainelli@...adcom.com>
Cc: Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>,
        Mukesh Ojha <mukesh.ojha@....qualcomm.com>,
        Stephen Boyd <swboyd@...omium.org>,
        Andre Draszik <andre.draszik@...aro.org>, linux-pm@...r.kernel.org,
        linux-kernel@...r.kernel.org, devicetree@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, linux-arm-msm@...r.kernel.org,
        Elliot Berman <quic_eberman@...cinc.com>,
        Shivendra Pratap <shivendra.pratap@....qualcomm.com>,
        Srinivas Kandagatla <srini@...nel.org>
Subject: [PATCH v13 01/10] power: reset: reboot-mode: Synchronize list
 traversal

List traversals must be synchronized to prevent race conditions
and data corruption. The reboot-mode list is not protected by a
lock currently, which can lead to concurrent access and race.

Introduce a mutex lock to guard all operations on the reboot-mode
list and ensure thread-safe access. The change prevents unsafe
concurrent access on reboot-mode list.

Signed-off-by: Shivendra Pratap <shivendra.pratap@....qualcomm.com>
---
 drivers/power/reset/reboot-mode.c | 24 ++++++++++++++++++++----
 include/linux/reboot-mode.h       |  4 ++++
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/drivers/power/reset/reboot-mode.c b/drivers/power/reset/reboot-mode.c
index fba53f638da04655e756b5f8b7d2d666d1379535..42bb99128ed3846d4bff62416dc31135ddeaeb90 100644
--- a/drivers/power/reset/reboot-mode.c
+++ b/drivers/power/reset/reboot-mode.c
@@ -29,9 +29,14 @@ static unsigned int get_reboot_mode_magic(struct reboot_mode_driver *reboot,
 	if (!cmd)
 		cmd = normal;
 
-	list_for_each_entry(info, &reboot->head, list)
-		if (!strcmp(info->mode, cmd))
+	mutex_lock(&reboot->rb_lock);
+	list_for_each_entry(info, &reboot->head, list) {
+		if (!strcmp(info->mode, cmd)) {
+			mutex_unlock(&reboot->rb_lock);
 			return info->magic;
+		}
+	}
+	mutex_unlock(&reboot->rb_lock);
 
 	/* try to match again, replacing characters impossible in DT */
 	if (strscpy(cmd_, cmd, sizeof(cmd_)) == -E2BIG)
@@ -41,9 +46,14 @@ static unsigned int get_reboot_mode_magic(struct reboot_mode_driver *reboot,
 	strreplace(cmd_, ',', '-');
 	strreplace(cmd_, '/', '-');
 
-	list_for_each_entry(info, &reboot->head, list)
-		if (!strcmp(info->mode, cmd_))
+	mutex_lock(&reboot->rb_lock);
+	list_for_each_entry(info, &reboot->head, list) {
+		if (!strcmp(info->mode, cmd_)) {
+			mutex_unlock(&reboot->rb_lock);
 			return info->magic;
+		}
+	}
+	mutex_unlock(&reboot->rb_lock);
 
 	return 0;
 }
@@ -77,7 +87,9 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
 	int ret;
 
 	INIT_LIST_HEAD(&reboot->head);
+	mutex_init(&reboot->rb_lock);
 
+	mutex_lock(&reboot->rb_lock);
 	for_each_property_of_node(np, prop) {
 		if (strncmp(prop->name, PREFIX, len))
 			continue;
@@ -113,12 +125,14 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
 	reboot->reboot_notifier.notifier_call = reboot_mode_notify;
 	register_reboot_notifier(&reboot->reboot_notifier);
 
+	mutex_unlock(&reboot->rb_lock);
 	return 0;
 
 error:
 	list_for_each_entry(info, &reboot->head, list)
 		kfree_const(info->mode);
 
+	mutex_unlock(&reboot->rb_lock);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(reboot_mode_register);
@@ -133,8 +147,10 @@ int reboot_mode_unregister(struct reboot_mode_driver *reboot)
 
 	unregister_reboot_notifier(&reboot->reboot_notifier);
 
+	mutex_lock(&reboot->rb_lock);
 	list_for_each_entry(info, &reboot->head, list)
 		kfree_const(info->mode);
+	mutex_unlock(&reboot->rb_lock);
 
 	return 0;
 }
diff --git a/include/linux/reboot-mode.h b/include/linux/reboot-mode.h
index 4a2abb38d1d612ec0fdf05eb18c98b210f631b7f..b73f80708197677db8dc2e43affc519782b7146e 100644
--- a/include/linux/reboot-mode.h
+++ b/include/linux/reboot-mode.h
@@ -2,11 +2,15 @@
 #ifndef __REBOOT_MODE_H__
 #define __REBOOT_MODE_H__
 
+#include <linux/mutex.h>
+
 struct reboot_mode_driver {
 	struct device *dev;
 	struct list_head head;
 	int (*write)(struct reboot_mode_driver *reboot, unsigned int magic);
 	struct notifier_block reboot_notifier;
+	/*Protects access to reboot mode list*/
+	struct mutex rb_lock;
 };
 
 int reboot_mode_register(struct reboot_mode_driver *reboot);

-- 
2.34.1