Commit dd2d2ac6 authored Oct 08, 2024 by Yonatan Maman Committed by Wen Zhiwei Nov 08, 2024

nouveau/dmem: Fix vulnerability in migrate_to_ram upon copy error

stable inclusion
from stable-v6.6.57
commit 697e3ddcf1f8b68bd531fc34eead27c000bdf3e1
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IB2M97

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=697e3ddcf1f8b68bd531fc34eead27c000bdf3e1



--------------------------------

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: 5be73b69 ("drm/nouveau/dmem: device memory helpers for SVM")
Signed-off-by: Yonatan Maman <Ymaman@Nvidia.com>
Co-developed-by: Gal Shalom <GalShalom@Nvidia.com>
Signed-off-by: Gal Shalom <GalShalom@Nvidia.com>
Reviewed-by: Ben Skeggs <bskeggs@nvidia.com>
Cc: stable@vger.kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20241008115943.990286-3-ymaman@nvidia.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Wen Zhiwei <wenzhiwei@kylinos.cn>

parent bcfcc7da

drivers/gpu/drm/nouveau/nouveau_dmem.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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;