linux-kernel - [PATCH 1/4][RFC v2] PM / sleep: Avoid accessing frozen

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]

Date:	Sun, 26 Jun 2016 00:18:30 +0800
From:	Chen Yu <yu.c.chen@...el.com>
To:	linux-pm@...r.kernel.org, x86@...nel.org
Cc:	"Rafael J. Wysocki" <rjw@...ysocki.net>,
	Len Brown <lenb@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>,
	"H. Peter Anvin" <hpa@...or.com>, Borislav Petkov <bp@...e.de>,
	Pavel Machek <pavel@....cz>, Brian Gerst <brgerst@...il.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...nel.org>,
	Varun Koyyalagunta <cpudebug@...ttech.com>,
	linux-kernel@...r.kernel.org, Chen Yu <yu.c.chen@...el.com>
Subject: [PATCH 1/4][RFC v2] PM / sleep: Avoid accessing frozen_cpus if it is NULL

frozen_cpus might be NULL if the allocation in previous
alloc_frozen_cpus failed, when CONFIG_CPUMASK_OFFSTACK
is set.

This patch avoid accessing this cpumask if it is NULL.

Signed-off-by: Chen Yu <yu.c.chen@...el.com>
---
 kernel/cpu.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/kernel/cpu.c b/kernel/cpu.c
index d948e44..d25266e 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -1021,6 +1021,8 @@ int disable_nonboot_cpus(void)
 {
 	int cpu, first_cpu, error = 0;
 
+	if (frozen_cpus == NULL)
+		return -ENOMEM;
 	cpu_maps_update_begin();
 	first_cpu = cpumask_first(cpu_online_mask);
 	/*
@@ -1072,6 +1074,8 @@ void enable_nonboot_cpus(void)
 {
 	int cpu, error;
 
+	if (frozen_cpus == NULL)
+		return;
 	/* Allow everyone to use the CPU hotplug again */
 	cpu_maps_update_begin();
 	WARN_ON(--cpu_hotplug_disabled < 0);
-- 
2.7.4