5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Yonatan Maman <Ymaman@xxxxxxxxxx>
commit 835745a377a4519decd1a36d6b926e369b3033e2 upstream.
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>
Co-developed-by: Gal Shalom <GalShalom@xxxxxxxxxx>
Signed-off-by: Gal Shalom <GalShalom@xxxxxxxxxx>
Reviewed-by: Ben Skeggs <bskeggs@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Danilo Krummrich <dakr@xxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20241008115943.990286-3-ymaman@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/nouveau/nouveau_dmem.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
@@ -139,7 +139,7 @@ static vm_fault_t nouveau_dmem_fault_cop
if (!spage || !(args->src[0] & MIGRATE_PFN_MIGRATE))
return 0;
- dpage = alloc_page_vma(GFP_HIGHUSER, vmf->vma, vmf->address);
+ dpage = alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO, vmf->vma, vmf->address);
if (!dpage)
return VM_FAULT_SIGBUS;
lock_page(dpage);
