linux-kernel - Re: [syzbot] Re: [syzbot] [pm?] possible deadlock in lock_system

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: <67b7daa8.050a0220.14d86d.0305.GAE@google.com>
Date: Thu, 20 Feb 2025 17:45:12 -0800
From: syzbot <syzbot+ace60642828c074eb913@...kaller.appspotmail.com>
To: linux-kernel@...r.kernel.org
Subject: Re: [syzbot] Re: [syzbot] [pm?] possible deadlock in lock_system_sleep

For archival purposes, forwarding an incoming command email to
linux-kernel@...r.kernel.org.

***

Subject: Re: [syzbot] [pm?] possible deadlock in lock_system_sleep
Author: lizhi.xu@...driver.com

#syz test

diff --git a/kernel/params.c b/kernel/params.c
index 0074d29c9b80..d19881fbb2ec 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -583,7 +583,9 @@ static ssize_t param_attr_store(const struct module_attribute *mattr,
 	if (!attribute->param->ops->set)
 		return -EPERM;
 
-	kernel_param_lock(mk->mod);
+	if (!kernel_param_trylock(mk->mod))
+		return -EPERM;
+
 	if (param_check_unsafe(attribute->param))
 		err = attribute->param->ops->set(buf, attribute->param);
 	else
@@ -607,6 +609,11 @@ void kernel_param_lock(struct module *mod)
 	mutex_lock(KPARAM_MUTEX(mod));
 }
 
+int kernel_param_trylock(struct module *mod)
+{
+	return mutex_trylock(KPARAM_MUTEX(mod));
+}
+
 void kernel_param_unlock(struct module *mod)
 {
 	mutex_unlock(KPARAM_MUTEX(mod));
diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
index bfb85fd13e1f..c7b1da7b9563 100644
--- a/include/linux/moduleparam.h
+++ b/include/linux/moduleparam.h
@@ -306,11 +306,15 @@ struct kparam_array
 
 #ifdef CONFIG_SYSFS
 extern void kernel_param_lock(struct module *mod);
+extern void kernel_param_trylock(struct module *mod);
 extern void kernel_param_unlock(struct module *mod);
 #else
 static inline void kernel_param_lock(struct module *mod)
 {
 }
+static inline void kernel_param_trylock(struct module *mod)
+{
+}
 static inline void kernel_param_unlock(struct module *mod)
 {
 }