Messages in this thread | | | Date | Mon, 2 Mar 2020 13:42:07 +0530 | From | Viresh Kumar <> | Subject | Re: [PATCH] KVM: X86: Fix dereference null cpufreq policy |
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On 02-03-20, 08:55, Paolo Bonzini wrote: > On 02/03/20 08:15, Wanpeng Li wrote: > > From: Wanpeng Li <wanpengli@tencent.com> > > > > cpufreq policy which is get by cpufreq_cpu_get() can be NULL if it is failure, > > this patch takes care of it. > > > > Fixes: aaec7c03de (KVM: x86: avoid useless copy of cpufreq policy) > > Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> > > Cc: Naresh Kamboju <naresh.kamboju@linaro.org> > > Signed-off-by: Wanpeng Li <wanpengli@tencent.com> > > My bad, I checked kobject_put but didn't check that kobj is first in > struct cpufreq_policy. > > I think we should do this in cpufreq_cpu_put or, even better, move the > kobject struct first in struct cpufreq_policy. Rafael, Viresh, any > objection? > > Paolo > > > policy = cpufreq_cpu_get(cpu); > > - if (policy && policy->cpuinfo.max_freq) > > - max_tsc_khz = policy->cpuinfo.max_freq; > > + if (policy) { > > + if (policy->cpuinfo.max_freq) > > + max_tsc_khz = policy->cpuinfo.max_freq; > > + cpufreq_cpu_put(policy); > > + }
I think this change makes sense and I am not sure why should we even try to support cpufreq_cpu_put(NULL).
-- viresh
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