| Message ID | 1562659447-39989-1-git-send-email-wen.yang99@zte.com.cn (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
| Series | [v5] cpufreq/pasemi: fix an use-after-free in pas_cpufreq_cpu_init() | expand |
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.yang99@zte.com.cn> > Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> > Cc: Viresh Kumar <viresh.kumar@linaro.org> > Cc: Michael Ellerman <mpe@ellerman.id.au> > Cc: linuxppc-dev@lists.ozlabs.org > Cc: linux-pm@vger.kernel.org > Cc: linux-kernel@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.kumar@linaro.org>
On Tuesday, July 9, 2019 10:12:05 AM CEST Viresh Kumar wrote: > 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.yang99@zte.com.cn> > > Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> > > Cc: Viresh Kumar <viresh.kumar@linaro.org> > > Cc: Michael Ellerman <mpe@ellerman.id.au> > > Cc: linuxppc-dev@lists.ozlabs.org > > Cc: linux-pm@vger.kernel.org > > Cc: linux-kernel@vger.kernel.org Patch applied. > > --- > > 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 :) And I added the blank line. > > + 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.kumar@linaro.org> > > Thanks!
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; + 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");
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: Michael Ellerman <mpe@ellerman.id.au> Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-pm@vger.kernel.org Cc: linux-kernel@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(-)