From fd9bb7e996bab9b9049fffe3f3d3b50dee191d27 Mon Sep 17 00:00:00 2001 From: Yonatan Maman Date: Tue, 8 Oct 2024 14:59:43 +0300 Subject: [PATCH] nouveau/dmem: Fix vulnerability in migrate_to_ram upon copy error 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 Co-developed-by: Gal Shalom Signed-off-by: Gal Shalom Reviewed-by: Ben Skeggs Cc: stable@vger.kernel.org Signed-off-by: Danilo Krummrich Link: https://patchwork.freedesktop.org/patch/msgid/20241008115943.990286-3-ymaman@nvidia.com Signed-off-by: Greg Kroah-Hartman --- 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 0ad5d87b5a8e..7c8f77ed0549 100644 --- 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_copy_one(struct nouveau_drm *drm, 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);