5.4-stable review patch. If anyone has any objections, please let me know.
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From: Yonatan Maman Ymaman@Nvidia.com
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@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... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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);