| Message ID | 1562899461-24045-1-git-send-email-wen.yang99@zte.com.cn (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
| Series | [v6] cpufreq/pasemi: fix an use-after-free in pas_cpufreq_cpu_init() | expand |
On 12-07-19, 10:44, 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: a9acc26b75f6 ("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 > --- > v6: keep the blank line and fix warning: label 'out_unmap_sdcpwr' defined but not used. > 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 | 26 ++++++++++++++------------ > 1 file changed, 14 insertions(+), 12 deletions(-) > > diff --git a/drivers/cpufreq/pasemi-cpufreq.c b/drivers/cpufreq/pasemi-cpufreq.c > index 6b1e4ab..7d557f9 100644 > --- a/drivers/cpufreq/pasemi-cpufreq.c > +++ b/drivers/cpufreq/pasemi-cpufreq.c > @@ -131,10 +131,18 @@ static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy) > int err = -ENODEV; > > cpu = of_get_cpu_node(policy->cpu, NULL); > + if (!cpu) > + goto out; > > + max_freqp = of_get_property(cpu, "clock-frequency", NULL); > of_node_put(cpu); > - if (!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 +179,6 @@ 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"); > > @@ -196,7 +194,11 @@ static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy) > policy->cur = pas_freqs[cur_astate].frequency; > ppc_proc_freq = policy->cur * 1000ul; > > - return cpufreq_generic_init(policy, pas_freqs, get_gizmo_latency()); > + err = cpufreq_generic_init(policy, pas_freqs, get_gizmo_latency()); So you are trying to fix an earlier issue here with this. Should have been a separate patch. Over that I have just sent a patch now to make this routine return void. https://lore.kernel.org/lkml/ee8cf5fb4b4a01fdf9199037ff6d835b935cfd13.1562902877.git.viresh.kumar@linaro.org/ So all you need to do is to remove the label out_unmap_sdcpwr instead. > + if (err) > + goto out_unmap_sdcpwr; > + > + return 0; > > out_unmap_sdcpwr: > iounmap(sdcpwr_mapbase); > -- > 2.9.5
On 16-07-19, 16:26, wen.yang99@zte.com.cn wrote: > Okay thank you. > Now this patch > (https://lore.kernel.org/lkml/ee8cf5fb4b4a01fdf9199037ff6d835b935cfd13.1562902877.git.viresh.kumar@linaro.org/) > seems to have not been merged into the linux-next. > > In order to avoid code conflicts, we will wait until this patch is merged in and then send v7. Please rebase on PM tree's linux-next branch instead and resend your patch. git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git
diff --git a/drivers/cpufreq/pasemi-cpufreq.c b/drivers/cpufreq/pasemi-cpufreq.c index 6b1e4ab..7d557f9 100644 --- a/drivers/cpufreq/pasemi-cpufreq.c +++ b/drivers/cpufreq/pasemi-cpufreq.c @@ -131,10 +131,18 @@ static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy) int err = -ENODEV; cpu = of_get_cpu_node(policy->cpu, NULL); + if (!cpu) + goto out; + max_freqp = of_get_property(cpu, "clock-frequency", NULL); of_node_put(cpu); - if (!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 +179,6 @@ 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"); @@ -196,7 +194,11 @@ static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy) policy->cur = pas_freqs[cur_astate].frequency; ppc_proc_freq = policy->cur * 1000ul; - return cpufreq_generic_init(policy, pas_freqs, get_gizmo_latency()); + err = cpufreq_generic_init(policy, pas_freqs, get_gizmo_latency()); + if (err) + goto out_unmap_sdcpwr; + + return 0; out_unmap_sdcpwr: iounmap(sdcpwr_mapbase);
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: a9acc26b75f6 ("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 --- v6: keep the blank line and fix warning: label 'out_unmap_sdcpwr' defined but not used. 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 | 26 ++++++++++++++------------ 1 file changed, 14 insertions(+), 12 deletions(-)