5.4-stable review patch. If anyone has any objections, please let me know.
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From: Dennis Beier nanovim@gmail.com
[ Upstream commit 592532a77b736b5153e0c2e4c74aa50af0a352ab ]
longhaul_exit() was calling cpufreq_cpu_get(0) without checking for a NULL policy pointer. On some systems, this could lead to a NULL dereference and a kernel warning or panic.
This patch adds a check using unlikely() and returns early if the policy is NULL.
Bugzilla: #219962
Signed-off-by: Dennis Beier nanovim@gmail.com Signed-off-by: Viresh Kumar viresh.kumar@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/cpufreq/longhaul.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/cpufreq/longhaul.c b/drivers/cpufreq/longhaul.c index 92d92e67ae0a1..a9887011f1fa1 100644 --- a/drivers/cpufreq/longhaul.c +++ b/drivers/cpufreq/longhaul.c @@ -956,6 +956,9 @@ static void __exit longhaul_exit(void) struct cpufreq_policy *policy = cpufreq_cpu_get(0); int i;
+ if (unlikely(!policy)) + return; + for (i = 0; i < numscales; i++) { if (mults[i] == maxmult) { struct cpufreq_freqs freqs;