From b82a225e57a334335a21462b75ee2223bc6efe6d Mon Sep 17 00:00:00 2001 From: Matthew Brost Date: Wed, 25 Mar 2026 16:16:08 -0700 Subject: [PATCH] drm/gpusvm: Reject VMAs with VM_IO or VM_PFNMAP when creating SVM ranges MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit VMAs marked with VM_IO or VM_PFNMAP are not backed by struct page objects, which GPUSVM requires in order to operate correctly. In particular, get_pages() relies on hmm_range_fault() to resolve struct pages for the target range. Attempting to create an SVM range on such VMAs results in repeated get_pages() failures and can lead to an infinite loop inside a driver’s page‑fault handler. Prevent this by rejecting ranges on VM_IO or VM_PFNMAP VMAs and returning -EIO. Fixes: 99624bdff867 ("drm/gpusvm: Add support for GPU Shared Virtual Memory") Signed-off-by: Matthew Brost Reviewed-by: Himal Prasad Ghimiray Link: https://patch.msgid.link/20260325231608.25581-1-matthew.brost@intel.com --- drivers/gpu/drm/drm_gpusvm.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/gpu/drm/drm_gpusvm.c b/drivers/gpu/drm/drm_gpusvm.c index 4b928fda5b12..7993e85c0566 100644 --- a/drivers/gpu/drm/drm_gpusvm.c +++ b/drivers/gpu/drm/drm_gpusvm.c @@ -1065,6 +1065,11 @@ drm_gpusvm_range_find_or_insert(struct drm_gpusvm *gpusvm, goto err_notifier_remove; } + if (vas->vm_flags & (VM_IO | VM_PFNMAP)) { + err = -EIO; + goto err_notifier_remove; + } + range = drm_gpusvm_range_find(notifier, fault_addr, fault_addr + 1); if (range) goto out_mmunlock;