From: Yonatan Maman <Ymaman@xxxxxxxxxx>
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@xxxxxxxxxx>
Signed-off-by: Gal Shalom <GalShalom@xxxxxxxxxx>
Co-developed-by: Gal Shalom <GalShalom@xxxxxxxxxx>
Reviewed-by: Ben Skeggs <bskeggs@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
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;
--
2.34.1
