On 09-07-19, 16:04, 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.yan...@zte.com.cn>
> Cc: "Rafael J. Wysocki" <r...@rjwysocki.net>
> Cc: Viresh Kumar <viresh.ku...@linaro.org>
> Cc: Michael Ellerman <m...@ellerman.id.au>
> Cc: linuxppc-dev@lists.ozlabs.org
> Cc: linux...@vger.kernel.org
> Cc: linux-ker...@vger.kernel.org
> ---
> v5: put together the code to get, use, and release cpu device_node.
> v4: restore the blank line.
> v3: fix a leaked reference.
> v2: clean up the code according to the advice of viresh.
>
> drivers/cpufreq/pasemi-cpufreq.c | 21 +++++++++------------
> 1 file changed, 9 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/cpufreq/pasemi-cpufreq.c
> b/drivers/cpufreq/pasemi-cpufreq.c
> index 6b1e4ab..1f0beb7 100644
> --- a/drivers/cpufreq/pasemi-cpufreq.c
> +++ b/drivers/cpufreq/pasemi-cpufreq.c
> @@ -131,10 +131,17 @@ static int pas_cpufreq_cpu_init(struct cpufreq_policy
> *policy)
> int err = -ENODEV;
>
> cpu = of_get_cpu_node(policy->cpu, NULL);
> -
> - of_node_put(cpu);
> if (!cpu)
> goto out;
I would have loved a blank line here :)
> + max_freqp = of_get_property(cpu, "clock-frequency", NULL);
> + of_node_put(cpu);
> + if (!max_freqp) {
> + err = -EINVAL;
> + goto out;
> + }
> +
> + /* we need the freq in kHz */
> + max_freq = *max_freqp / 1000;
>
> dn = of_find_compatible_node(NULL, NULL, "1682m-sdc");
> if (!dn)
> @@ -171,16 +178,6 @@ static int pas_cpufreq_cpu_init(struct cpufreq_policy
> *policy)
> }
>
> pr_debug("init cpufreq on CPU %d\n", policy->cpu);
> -
> - max_freqp = of_get_property(cpu, "clock-frequency", NULL);
> - if (!max_freqp) {
> - err = -EINVAL;
> - goto out_unmap_sdcpwr;
> - }
> -
> - /* we need the freq in kHz */
> - max_freq = *max_freqp / 1000;
> -
> pr_debug("max clock-frequency is at %u kHz\n", max_freq);
> pr_debug("initializing frequency table\n");
Though, enough versions have happened now.
Acked-by: Viresh Kumar <viresh.ku...@linaro.org>
--
viresh
