From: Yongqiang Liu liuyongqiang13@huawei.com
commit 5c51054896bcce1d33d39fead2af73fec24f40b6 upstream.
In cpufreq_policy_alloc(), it will call uninitialed completion in cpufreq_sysfs_release() when kobject_init_and_add() fails. And that will cause a crash such as the following page fault in complete:
BUG: unable to handle page fault for address: fffffffffffffff8 [..] RIP: 0010:complete+0x98/0x1f0 [..] Call Trace: kobject_put+0x1be/0x4c0 cpufreq_online.cold+0xee/0x1fd cpufreq_add_dev+0x183/0x1e0 subsys_interface_register+0x3f5/0x4e0 cpufreq_register_driver+0x3b7/0x670 acpi_cpufreq_init+0x56c/0x1000 [acpi_cpufreq] do_one_initcall+0x13d/0x780 do_init_module+0x1c3/0x630 load_module+0x6e67/0x73b0 __do_sys_finit_module+0x181/0x240 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd
Fixes: 4ebe36c94aed ("cpufreq: Fix kobject memleak") Signed-off-by: Yongqiang Liu liuyongqiang13@huawei.com Acked-by: Viresh Kumar viresh.kumar@linaro.org Cc: 5.2+ stable@vger.kernel.org # 5.2+ Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/cpufreq/cpufreq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1211,6 +1211,7 @@ static struct cpufreq_policy *cpufreq_po if (!zalloc_cpumask_var(&policy->real_cpus, GFP_KERNEL)) goto err_free_rcpumask;
+ init_completion(&policy->kobj_unregister); ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, cpufreq_global_kobject, "policy%u", cpu); if (ret) { @@ -1249,7 +1250,6 @@ static struct cpufreq_policy *cpufreq_po init_rwsem(&policy->rwsem); spin_lock_init(&policy->transition_lock); init_waitqueue_head(&policy->transition_wait); - init_completion(&policy->kobj_unregister); INIT_WORK(&policy->update, handle_update);
policy->cpu = cpu;