Re: [PATCH] drm/xe/configfs: free aux. array after storing the wa_bb

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Sat, Nov 29, 2025 at 11:25:41PM +0100, Michał Grzelak wrote:
> When commands issued via configfs are executed mid- or post GPU context
> restoration, a temporary buffer is reallocated in order to store all of
> commands of varying count. However, after content of the buffer has been
> copied to the desired location it is never freed, which causes following
> memory leak to appear when running igt@xe_configfs@ctx-restore-mid-bb:
> 
>     kmemleak_alloc+0x4a/0x90
>     __kmalloc_node_track_caller_noprof+0x645/0x9d0
>     krealloc_node_align_noprof+0x206/0x3c0
>     wa_bb_store+0xf4/0x2c0 [xe]
>     ctx_restore_mid_bb_store+0x21/0x30 [xe]
>     configfs_write_iter+0xe6/0x150
>     vfs_write+0x231/0x540
>     ksys_write+0x6d/0xf0
>     __x64_sys_write+0x19/0x30
>     x64_sys_call+0x79/0x2350
>     do_syscall_64+0x93/0x10f0
>     entry_SYSCALL_64_after_hwframe+0x76/0x7e
> 
> Deallocate temporary array upon finishing the store of batch buffer
> into wa_bb.
> 
> Fixes: 39ac06f7006f ("drm/xe/configfs: Add post context restore bb")

this hash is wrong:

Fixes: 39ac06f70062 ("drm/xe/configfs: Add post context restore bb")

> Signed-off-by: Michał Grzelak <michal.grzelak@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_configfs.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_configfs.c b/drivers/gpu/drm/xe/xe_configfs.c
> index 9f6251b1008b..f9a64352138b 100644
> --- a/drivers/gpu/drm/xe/xe_configfs.c
> +++ b/drivers/gpu/drm/xe/xe_configfs.c
> @@ -789,6 +789,8 @@ static ssize_t wa_bb_store(struct wa_bb wa_bb[static XE_ENGINE_CLASS_MAX],
>  
>  	memcpy(wa_bb, tmp_wa_bb, sizeof(tmp_wa_bb));
>  
> +	kfree(tmp);

hmm...

do we need to change the kfree added in the xe_config_device_release()?

> +
>  	return len;
>  }
>  
> -- 
> 2.45.2
>