From: Armin Wolf <W_Armin@xxxxxx> [ Upstream commit e18afcb7b2a12b635ac10081f943fcf84ddacc51 ] 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> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 55437f5e0c3ae..bd6a7857ce058 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; -- 2.43.0