| Message ID | 20210104130227.35354-1-colin.king@canonical.com |
|---|---|
| State | New |
| Headers | show |
| Series | [next] cpufreq: powernow-k8: add null check to policy to avoid null pointer dereference | expand |
On 04-01-21, 13:02, Colin King wrote: > From: Colin Ian King <colin.king@canonical.com> > > Currently there is an unlikely case where cpufreq_cpu_get returns a > null policy and this will cause a null pointer dereference later on. > Fix this by adding a null check and adding an error return. > > Addresses-Coverity: ("Dereference null return") > Fixes: b43a7ffbf33b ("cpufreq: Notify all policy->cpus in cpufreq_notify_transition()") > Signed-off-by: Colin Ian King <colin.king@canonical.com> > --- > drivers/cpufreq/powernow-k8.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/cpufreq/powernow-k8.c b/drivers/cpufreq/powernow-k8.c > index 0acc9e241cd7..c5368545ba1f 100644 > --- a/drivers/cpufreq/powernow-k8.c > +++ b/drivers/cpufreq/powernow-k8.c > @@ -913,6 +913,8 @@ static int transition_frequency_fidvid(struct powernow_k8_data *data, The caller already has a pointer to the policy, you should rather pass that here instead of doing cpufreq_cpu_get/put. > freqs.new = find_khz_freq_from_fid(fid); > > policy = cpufreq_cpu_get(smp_processor_id()); > + if (!policy) > + return 1; > cpufreq_cpu_put(policy); > > cpufreq_freq_transition_begin(policy, &freqs); > -- > 2.29.2 -- viresh
diff --git a/drivers/cpufreq/powernow-k8.c b/drivers/cpufreq/powernow-k8.c index 0acc9e241cd7..c5368545ba1f 100644 --- a/drivers/cpufreq/powernow-k8.c +++ b/drivers/cpufreq/powernow-k8.c @@ -913,6 +913,8 @@ static int transition_frequency_fidvid(struct powernow_k8_data *data, freqs.new = find_khz_freq_from_fid(fid); policy = cpufreq_cpu_get(smp_processor_id()); + if (!policy) + return 1; cpufreq_cpu_put(policy); cpufreq_freq_transition_begin(policy, &freqs);