Re: [PATCH v4 1/3] drm/panthor: Check for sparse binding range overflow
From: Liviu Dudau
Date: Mon Jul 06 2026 - 08:50:35 EST
On Sat, Jul 04, 2026 at 05:46:44AM +0100, Adrián Larumbe wrote:
> This check is being already carried out further down the call stack inside
> drm_gpuvm_sm_map -> drm_gpuvm_range_valid, but it's best to fail early in
> the driver before GPUVM functions are invoked so that we won't waste time
> allocating vm_bind context resources.
>
> Reported-by: Sashiko <noreply@xxxxxxxxxxx>
> Closes: https://sashiko.dev/#/message/20260623204220.CDB1B1F000E9%40smtp.kernel.org
> Fixes: 12cf826bf1dd ("drm/panthor: Support sparse mappings")
> Signed-off-by: Adrián Larumbe <adrian.larumbe@xxxxxxxxxxxxx>
Reviewed-by: Liviu Dudau <liviu.dudau@xxxxxxx>
Best regards,
Liviu
> ---
> drivers/gpu/drm/panthor/panthor_mmu.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c
> index 31cc57029c12..163231c1703d 100644
> --- a/drivers/gpu/drm/panthor/panthor_mmu.c
> +++ b/drivers/gpu/drm/panthor/panthor_mmu.c
> @@ -2975,12 +2975,16 @@ panthor_vm_bind_prepare_op_ctx(struct drm_file *file,
> {
> ssize_t vm_pgsz = panthor_vm_page_size(vm);
> struct drm_gem_object *gem;
> + u64 end;
> int ret;
>
> /* Aligned on page size. */
> if (!IS_ALIGNED(op->va | op->size | op->bo_offset, vm_pgsz))
> return -EINVAL;
>
> + if (check_add_overflow(op->va, op->size, &end))
> + return -EINVAL;
> +
> switch (op->flags & DRM_PANTHOR_VM_BIND_OP_TYPE_MASK) {
> case DRM_PANTHOR_VM_BIND_OP_TYPE_MAP:
> if (!(op->flags & DRM_PANTHOR_VM_BIND_OP_MAP_SPARSE)) {
>
> --
> 2.55.0
>
--
====================
| I would like to |
| fix the world, |
| but they're not |
| giving me the |
\ source code! /
---------------
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