I had applied the first version before I noticed the second.

But I've reverted it, and applied this. So all should be correct now.

Bruce

In message: [linux-yocto][v6.12/standard/x86 and 
v6.12/standard/preempt-rt/x86][PATCH v2]  platform/x86: intel_pmc_ipc: fix ACPI 
buffer memory leak
on 25/11/2025 [email protected] wrote:

> From: Yongxin Liu <[email protected]>
> 
> The intel_pmc_ipc() function uses ACPI_ALLOCATE_BUFFER to allocate memory
> for the ACPI evaluation result but never frees it, causing a 192-byte
> memory leak on each call.
> 
> This leak is triggered during network interface initialization when the
> stmmac driver calls intel_mac_finish() -> intel_pmc_ipc().
> 
>   unreferenced object 0xffff96a848d6ea80 (size 192):
>     comm "dhcpcd", pid 541, jiffies 4294684345
>     hex dump (first 32 bytes):
>       04 00 00 00 05 00 00 00 98 ea d6 48 a8 96 ff ff  ...........H....
>       00 00 00 00 00 00 00 00 01 00 00 00 00 00 00 00  ................
>     backtrace (crc b1564374):
>       kmemleak_alloc+0x2d/0x40
>       __kmalloc_noprof+0x2fa/0x730
>       acpi_ut_initialize_buffer+0x83/0xc0
>       acpi_evaluate_object+0x29a/0x2f0
>       intel_pmc_ipc+0xfd/0x170
>       intel_mac_finish+0x168/0x230
>       stmmac_mac_finish+0x3d/0x50
>       phylink_major_config+0x22b/0x5b0
>       phylink_mac_initial_config.constprop.0+0xf1/0x1b0
>       phylink_start+0x8e/0x210
>       __stmmac_open+0x12c/0x2b0
>       stmmac_open+0x23c/0x380
>       __dev_open+0x11d/0x2c0
>       __dev_change_flags+0x1d2/0x250
>       netif_change_flags+0x2b/0x70
>       dev_change_flags+0x40/0xb0
> 
> Add kfree() to properly release the allocated buffer.
> 
> Cc: [email protected]
> Fixes: 7e2f7e25f6ff ("arch: x86: add IPC mailbox accessor function and add 
> SoC register access")
> Signed-off-by: Yongxin Liu <[email protected]>
> ---
>  arch/x86/platform/intel/pmc_ipc.c | 14 +++++++++-----
>  1 file changed, 9 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/x86/platform/intel/pmc_ipc.c 
> b/arch/x86/platform/intel/pmc_ipc.c
> index a96234982710..85ec9e0d8312 100644
> --- a/arch/x86/platform/intel/pmc_ipc.c
> +++ b/arch/x86/platform/intel/pmc_ipc.c
> @@ -28,7 +28,7 @@ int intel_pmc_ipc(struct pmc_ipc_cmd *ipc_cmd, u32 *rbuf)
>       };
>       struct acpi_object_list arg_list = { PMC_IPCS_PARAM_COUNT, params };
>       union acpi_object *obj;
> -     int status;
> +     int status, ret = 0;
>  
>       if (!ipc_cmd || !rbuf)
>               return -EINVAL;
> @@ -56,18 +56,22 @@ int intel_pmc_ipc(struct pmc_ipc_cmd *ipc_cmd, u32 *rbuf)
>       if (obj && obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 5) {
>               const union acpi_object *objs = obj->package.elements;
>  
> -             if ((u8)objs[0].integer.value != 0)
> -                     return -EINVAL;
> +             if ((u8)objs[0].integer.value != 0) {
> +                     ret = -EINVAL;
> +                     goto out;
> +             }
>  
>               rbuf[0] = objs[1].integer.value;
>               rbuf[1] = objs[2].integer.value;
>               rbuf[2] = objs[3].integer.value;
>               rbuf[3] = objs[4].integer.value;
>       } else {
> -             return -EINVAL;
> +             ret = -EINVAL;
>       }
>  
> -     return 0;
> +out:
> +     kfree(obj);
> +     return ret;
>  }
>  EXPORT_SYMBOL(intel_pmc_ipc);
>  
> -- 
> 2.49.1
> 
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