From: qiwuchen55@gmail.com
To: kgene@kernel.org, krzk@kernel.org, rjw@rjwysocki.net,
viresh.kumar@linaro.org
Cc: linux-arm-kernel@lists.infradead.org,
linux-samsung-soc@vger.kernel.org, linux-pm@vger.kernel.org,
linux-kernel@vger.kernel.org, chenqiwu <chenqiwu@xiaomi.com>
Subject: [PATCH] cpufreq: s3c: avoid use after free issue in xxx_cpufreq_reboot_notifier_evt()
Date: Sat, 28 Dec 2019 14:43:59 +0800 [thread overview]
Message-ID: <1577515439-14477-1-git-send-email-qiwuchen55@gmail.com> (raw)
From: chenqiwu <chenqiwu@xiaomi.com>
There is a potential UAF issue in xxx_cpufreq_reboot_notifier_evt() that
the cpufreq policy of cpu0 has been released before using it. So we should
make a judgement to avoid it.
Signed-off-by: chenqiwu <chenqiwu@xiaomi.com>
---
drivers/cpufreq/s3c2416-cpufreq.c | 11 ++++++++++-
drivers/cpufreq/s5pv210-cpufreq.c | 10 +++++++++-
2 files changed, 19 insertions(+), 2 deletions(-)
diff --git a/drivers/cpufreq/s3c2416-cpufreq.c b/drivers/cpufreq/s3c2416-cpufreq.c
index 1069103..0f576ba 100644
--- a/drivers/cpufreq/s3c2416-cpufreq.c
+++ b/drivers/cpufreq/s3c2416-cpufreq.c
@@ -304,6 +304,7 @@ static int s3c2416_cpufreq_reboot_notifier_evt(struct notifier_block *this,
{
struct s3c2416_data *s3c_freq = &s3c2416_cpufreq;
int ret;
+ struct cpufreq_policy policy;
mutex_lock(&cpufreq_lock);
@@ -318,7 +319,15 @@ static int s3c2416_cpufreq_reboot_notifier_evt(struct notifier_block *this,
*/
if (s3c_freq->is_dvs) {
pr_debug("cpufreq: leave dvs on reboot\n");
- ret = cpufreq_driver_target(cpufreq_cpu_get(0), FREQ_SLEEP, 0);
+
+ memset(&policy, 0, sizeof(policy));
+ ret = cpufreq_get_policy(&policy, 0);
+ if (ret < 0) {
+ pr_debug("cpufreq: get no policy for cpu0\n");
+ return NOTIFY_BAD;
+ }
+
+ ret = cpufreq_driver_target(&policy, FREQ_SLEEP, 0);
if (ret < 0)
return NOTIFY_BAD;
}
diff --git a/drivers/cpufreq/s5pv210-cpufreq.c b/drivers/cpufreq/s5pv210-cpufreq.c
index 5d10030..d99b4b1 100644
--- a/drivers/cpufreq/s5pv210-cpufreq.c
+++ b/drivers/cpufreq/s5pv210-cpufreq.c
@@ -555,8 +555,16 @@ static int s5pv210_cpufreq_reboot_notifier_event(struct notifier_block *this,
unsigned long event, void *ptr)
{
int ret;
+ struct cpufreq_policy *policy;
- ret = cpufreq_driver_target(cpufreq_cpu_get(0), SLEEP_FREQ, 0);
+ policy = cpufreq_cpu_get(0);
+ if (!policy) {
+ pr_debug("cpufreq: get no policy for cpu0\n");
+ return NOTIFY_BAD;
+ }
+
+ ret = cpufreq_driver_target(policy, SLEEP_FREQ, 0);
+ cpufreq_cpu_put(policy);
if (ret < 0)
return NOTIFY_BAD;
--
1.9.1
next reply other threads:[~2019-12-28 6:44 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-28 6:43 qiwuchen55 [this message]
2020-01-06 5:48 ` [PATCH] cpufreq: s3c: avoid use after free issue in xxx_cpufreq_reboot_notifier_evt() Viresh Kumar
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1577515439-14477-1-git-send-email-qiwuchen55@gmail.com \
--to=qiwuchen55@gmail.com \
--cc=chenqiwu@xiaomi.com \
--cc=kgene@kernel.org \
--cc=krzk@kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=linux-samsung-soc@vger.kernel.org \
--cc=rjw@rjwysocki.net \
--cc=viresh.kumar@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).