[PATCH v3 4/5] drm_lease.c: copy user-array safely

Philipp Stanner pstanner at redhat.com
Wed Sep 20 05:36:12 PDT 2023


Currently, there is no overflow-check with memdup_user().

Use the new function memdup_array_user() instead of memdup_user() for
duplicating the user-space array safely.

Suggested-by: David Airlie <airlied at redhat.com>
Signed-off-by: Philipp Stanner <pstanner at redhat.com>
Reviewed-by: Kees Cook <keescook at chromium.org>
Reviewed-by: Zack Rusin <zackr at vmware.com>
---
 drivers/gpu/drm/drm_lease.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_lease.c b/drivers/gpu/drm/drm_lease.c
index 150fe1555068..94375c6a5425 100644
--- a/drivers/gpu/drm/drm_lease.c
+++ b/drivers/gpu/drm/drm_lease.c
@@ -510,8 +510,8 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev,
 	/* Handle leased objects, if any */
 	idr_init(&leases);
 	if (object_count != 0) {
-		object_ids = memdup_user(u64_to_user_ptr(cl->object_ids),
-					 array_size(object_count, sizeof(__u32)));
+		object_ids = memdup_array_user(u64_to_user_ptr(cl->object_ids),
+					       object_count, sizeof(__u32));
 		if (IS_ERR(object_ids)) {
 			ret = PTR_ERR(object_ids);
 			idr_destroy(&leases);
-- 
2.41.0




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