cpufreq: cppc_cpufreq: Fix cppc_cpufreq_init() failure path
authorChunyu Hu <chuhu@redhat.com>
Mon, 5 Mar 2018 05:40:38 +0000 (13:40 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 30 May 2018 05:52:30 +0000 (07:52 +0200)
[ Upstream commit 55b55abc17f238c61921360e61dde90dd9a326d1 ]

Kmemleak reported the below leak. When cppc_cpufreq_init went into
failure path, the cpu mask is not freed. After fix, this report is
gone. And to avaoid potential NULL pointer reference, check the cpu
value first.

unreferenced object 0xffff800fd5ea4880 (size 128):
  comm "swapper/0", pid 1, jiffies 4294939510 (age 668.680s)
  hex dump (first 32 bytes):
    00 00 00 00 20 00 00 00 00 00 00 00 00 00 00 00  .... ...........
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffff0000082c4ae4>] __kmalloc_node+0x278/0x634
    [<ffff0000088f4a74>] alloc_cpumask_var_node+0x28/0x60
    [<ffff0000088f4af0>] zalloc_cpumask_var+0x14/0x1c
    [<ffff000008d20254>] cppc_cpufreq_init+0xd0/0x19c
    [<ffff000008083828>] do_one_initcall+0xec/0x15c
    [<ffff000008cd1018>] kernel_init_freeable+0x1f4/0x2a4
    [<ffff0000089099b0>] kernel_init+0x18/0x10c
    [<ffff000008084d50>] ret_from_fork+0x10/0x18
    [<ffffffffffffffff>] 0xffffffffffffffff

Signed-off-by: Chunyu Hu <chuhu@redhat.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/cpufreq/cppc_cpufreq.c

index a81f7d5..8b432d6 100644 (file)
@@ -243,8 +243,13 @@ static int __init cppc_cpufreq_init(void)
        return ret;
 
 out:
-       for_each_possible_cpu(i)
-               kfree(all_cpu_data[i]);
+       for_each_possible_cpu(i) {
+               cpu = all_cpu_data[i];
+               if (!cpu)
+                       break;
+               free_cpumask_var(cpu->shared_cpu_map);
+               kfree(cpu);
+       }
 
        kfree(all_cpu_data);
        return -ENODEV;