From: Yonatan Maman Ymaman@Nvidia.com
The `nouveau_dmem_copy_one` function ensures that the copy push command is sent to the device firmware but does not track whether it was executed successfully.
In the case of a copy error (e.g., firmware or hardware failure), the copy push command will be sent via the firmware channel, and `nouveau_dmem_copy_one` will likely report success, leading to the `migrate_to_ram` function returning a dirty HIGH_USER page to the user.
This can result in a security vulnerability, as a HIGH_USER page that may contain sensitive or corrupted data could be returned to the user.
To prevent this vulnerability, we allocate a zero page. Thus, in case of an error, a non-dirty (zero) page will be returned to the user.
Fixes: 5be73b690875 ("drm/nouveau/dmem: device memory helpers for SVM") Signed-off-by: Yonatan Maman Ymaman@Nvidia.com Signed-off-by: Gal Shalom GalShalom@Nvidia.com Co-developed-by: Gal Shalom GalShalom@Nvidia.com Reviewed-by: Ben Skeggs bskeggs@nvidia.com Cc: stable@vger.kernel.org --- drivers/gpu/drm/nouveau/nouveau_dmem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c index 6fb65b01d778..097bd3af0719 100644 --- a/drivers/gpu/drm/nouveau/nouveau_dmem.c +++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c @@ -193,7 +193,7 @@ static vm_fault_t nouveau_dmem_migrate_to_ram(struct vm_fault *vmf) if (!spage || !(src & MIGRATE_PFN_MIGRATE)) goto done;
- dpage = alloc_page_vma(GFP_HIGHUSER, vmf->vma, vmf->address); + dpage = alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO, vmf->vma, vmf->address); if (!dpage) goto done;