* [PATCH v2] cpufreq/pasemi: fix an use-after-free in pas_cpufreq_cpu_init()
@ 2019-07-08 7:19 Wen Yang
2019-07-08 7:44 ` Viresh Kumar
0 siblings, 1 reply; 3+ messages in thread
From: Wen Yang @ 2019-07-08 7:19 UTC (permalink / raw)
To: linux-kernel
Cc: wang.yi59, linux-pm, Viresh Kumar, Rafael J. Wysocki,
xue.zhihong, cheng.shengyu, linuxppc-dev, Wen Yang
The cpu variable is still being used in the of_get_property() call
after the of_node_put() call, which may result in use-after-free.
Fixes: a9acc26b75f ("cpufreq/pasemi: fix possible object reference leak")
Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
v2: clean up the code according to the advice of viresh.
drivers/cpufreq/pasemi-cpufreq.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/cpufreq/pasemi-cpufreq.c b/drivers/cpufreq/pasemi-cpufreq.c
index 6b1e4ab..c6d464b 100644
--- a/drivers/cpufreq/pasemi-cpufreq.c
+++ b/drivers/cpufreq/pasemi-cpufreq.c
@@ -128,20 +128,18 @@ static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy)
int cur_astate, idx;
struct resource res;
struct device_node *cpu, *dn;
- int err = -ENODEV;
+ int err;
cpu = of_get_cpu_node(policy->cpu, NULL);
-
- of_node_put(cpu);
if (!cpu)
- goto out;
+ return -ENODEV;
dn = of_find_compatible_node(NULL, NULL, "1682m-sdc");
if (!dn)
dn = of_find_compatible_node(NULL, NULL,
"pasemi,pwrficient-sdc");
if (!dn)
- goto out;
+ return -ENODEV;
err = of_address_to_resource(dn, 0, &res);
of_node_put(dn);
if (err)
@@ -196,6 +194,7 @@ static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy)
policy->cur = pas_freqs[cur_astate].frequency;
ppc_proc_freq = policy->cur * 1000ul;
+ of_node_put(cpu);
return cpufreq_generic_init(policy, pas_freqs, get_gizmo_latency());
out_unmap_sdcpwr:
@@ -204,6 +203,7 @@ static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy)
out_unmap_sdcasr:
iounmap(sdcasr_mapbase);
out:
+ of_node_put(cpu);
return err;
}
--
2.9.5
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v2] cpufreq/pasemi: fix an use-after-free in pas_cpufreq_cpu_init()
2019-07-08 7:19 [PATCH v2] cpufreq/pasemi: fix an use-after-free in pas_cpufreq_cpu_init() Wen Yang
@ 2019-07-08 7:44 ` Viresh Kumar
2019-07-08 8:26 ` [PATCH v2] cpufreq/pasemi: fix an use-after-free inpas_cpufreq_cpu_init() wen.yang99
0 siblings, 1 reply; 3+ messages in thread
From: Viresh Kumar @ 2019-07-08 7:44 UTC (permalink / raw)
To: Wen Yang
Cc: wang.yi59, linux-pm, Rafael J. Wysocki, linux-kernel,
xue.zhihong, cheng.shengyu, linuxppc-dev
On 08-07-19, 15:19, Wen Yang wrote:
> The cpu variable is still being used in the of_get_property() call
> after the of_node_put() call, which may result in use-after-free.
>
> Fixes: a9acc26b75f ("cpufreq/pasemi: fix possible object reference leak")
> Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> Cc: Viresh Kumar <viresh.kumar@linaro.org>
> Cc: linuxppc-dev@lists.ozlabs.org
> Cc: linux-pm@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> ---
> v2: clean up the code according to the advice of viresh.
>
> drivers/cpufreq/pasemi-cpufreq.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/cpufreq/pasemi-cpufreq.c b/drivers/cpufreq/pasemi-cpufreq.c
> index 6b1e4ab..c6d464b 100644
> --- a/drivers/cpufreq/pasemi-cpufreq.c
> +++ b/drivers/cpufreq/pasemi-cpufreq.c
> @@ -128,20 +128,18 @@ static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy)
> int cur_astate, idx;
> struct resource res;
> struct device_node *cpu, *dn;
> - int err = -ENODEV;
> + int err;
>
> cpu = of_get_cpu_node(policy->cpu, NULL);
> -
> - of_node_put(cpu);
> if (!cpu)
> - goto out;
> + return -ENODEV;
>
> dn = of_find_compatible_node(NULL, NULL, "1682m-sdc");
> if (!dn)
> dn = of_find_compatible_node(NULL, NULL,
> "pasemi,pwrficient-sdc");
> if (!dn)
> - goto out;
> + return -ENODEV;
This change looks incorrect. You still need to drop reference to cpu ?
> err = of_address_to_resource(dn, 0, &res);
> of_node_put(dn);
> if (err)
> @@ -196,6 +194,7 @@ static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy)
> policy->cur = pas_freqs[cur_astate].frequency;
> ppc_proc_freq = policy->cur * 1000ul;
>
> + of_node_put(cpu);
> return cpufreq_generic_init(policy, pas_freqs, get_gizmo_latency());
>
> out_unmap_sdcpwr:
> @@ -204,6 +203,7 @@ static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy)
> out_unmap_sdcasr:
> iounmap(sdcasr_mapbase);
> out:
> + of_node_put(cpu);
> return err;
> }
>
> --
> 2.9.5
--
viresh
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2] cpufreq/pasemi: fix an use-after-free inpas_cpufreq_cpu_init()
2019-07-08 7:44 ` Viresh Kumar
@ 2019-07-08 8:26 ` wen.yang99
0 siblings, 0 replies; 3+ messages in thread
From: wen.yang99 @ 2019-07-08 8:26 UTC (permalink / raw)
To: viresh.kumar
Cc: wang.yi59, linux-pm, rjw, linux-kernel, xue.zhihong,
cheng.shengyu, linuxppc-dev
[-- Attachment #1.1: Type: text/plain, Size: 1674 bytes --]
> > The cpu variable is still being used in the of_get_property() call
> > after the of_node_put() call, which may result in use-after-free.
> >
> > Fixes: a9acc26b75f ("cpufreq/pasemi: fix possible object reference leak")
> > Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
> > Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> > Cc: Viresh Kumar <viresh.kumar@linaro.org>
> > Cc: linuxppc-dev@lists.ozlabs.org
> > Cc: linux-pm@vger.kernel.org
> > Cc: linux-kernel@vger.kernel.org
> > ---
> > v2: clean up the code according to the advice of viresh.
> >
> > drivers/cpufreq/pasemi-cpufreq.c | 10 +++++-----
> > 1 file changed, 5 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/cpufreq/pasemi-cpufreq.c b/drivers/cpufreq/pasemi-cpufreq.c
> > index 6b1e4ab..c6d464b 100644
> > --- a/drivers/cpufreq/pasemi-cpufreq.c
> > +++ b/drivers/cpufreq/pasemi-cpufreq.c
> > @@ -128,20 +128,18 @@ static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy)
> > int cur_astate, idx;
> > struct resource res;
> > struct device_node *cpu, *dn;
> > - int err = -ENODEV;
> > + int err;
> >
> > cpu = of_get_cpu_node(policy->cpu, NULL);
> > -
> > - of_node_put(cpu);
> > if (!cpu)
> > - goto out;
> > + return -ENODEV;
> >
>
>
> > dn = of_find_compatible_node(NULL, NULL, "1682m-sdc");
> > if (!dn)
> > dn = of_find_compatible_node(NULL, NULL,
> > "pasemi,pwrficient-sdc");
> > if (!dn)
> > - goto out;
> > + return -ENODEV;
>
> This change looks incorrect. You still need to drop reference to cpu ?
>
Thanks!
We will fix it immediately.
--
Thanks and regards,
Wen
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-07-08 8:29 UTC | newest]
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2019-07-08 7:19 [PATCH v2] cpufreq/pasemi: fix an use-after-free in pas_cpufreq_cpu_init() Wen Yang
2019-07-08 7:44 ` Viresh Kumar
2019-07-08 8:26 ` [PATCH v2] cpufreq/pasemi: fix an use-after-free inpas_cpufreq_cpu_init() wen.yang99
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