On Tue, Feb 13, 2024 at 1:42 AM Armin Wolf <W_Armin@xxxxxx> wrote:
>
> After unregistering the CPU idle device, the memory associated with
> it is not freed, leading to a memory leak:
>
> unreferenced object 0xffff896282f6c000 (size 1024):
> comm "swapper/0", pid 1, jiffies 4294893170
> hex dump (first 32 bytes):
> 00 00 00 00 0b 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 (crc 8836a742):
> [<ffffffff993495ed>] kmalloc_trace+0x29d/0x340
> [<ffffffff9972f3b3>] acpi_processor_power_init+0xf3/0x1c0
> [<ffffffff9972d263>] __acpi_processor_start+0xd3/0xf0
> [<ffffffff9972d2bc>] acpi_processor_start+0x2c/0x50
> [<ffffffff99805872>] really_probe+0xe2/0x480
> [<ffffffff99805c98>] __driver_probe_device+0x78/0x160
> [<ffffffff99805daf>] driver_probe_device+0x1f/0x90
> [<ffffffff9980601e>] __driver_attach+0xce/0x1c0
> [<ffffffff99803170>] bus_for_each_dev+0x70/0xc0
> [<ffffffff99804822>] bus_add_driver+0x112/0x210
> [<ffffffff99807245>] driver_register+0x55/0x100
> [<ffffffff9aee4acb>] acpi_processor_driver_init+0x3b/0xc0
> [<ffffffff990012d1>] do_one_initcall+0x41/0x300
> [<ffffffff9ae7c4b0>] kernel_init_freeable+0x320/0x470
> [<ffffffff99b231f6>] kernel_init+0x16/0x1b0
> [<ffffffff99042e6d>] ret_from_fork+0x2d/0x50
>
> Fix this by freeing the CPU idle device after unregistering it.
>
> Fixes: 3d339dcbb56d ("cpuidle / ACPI : move cpuidle_device field out of the acpi_processor_power structure")
> Signed-off-by: Armin Wolf <W_Armin@xxxxxx>
> ---
> drivers/acpi/processor_idle.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
> index 55437f5e0c3a..bd6a7857ce05 100644
> --- a/drivers/acpi/processor_idle.c
> +++ b/drivers/acpi/processor_idle.c
> @@ -1430,6 +1430,8 @@ int acpi_processor_power_exit(struct acpi_processor *pr)
> acpi_processor_registered--;
> if (acpi_processor_registered == 0)
> cpuidle_unregister_driver(&acpi_idle_driver);
> +
> + kfree(dev);
> }
>
> pr->flags.power_setup_done = 0;
> --
Applied as 6.9 material, thanks!
