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

From: Philipp Stanner
Date: Wed Sep 20 2023 - 08:38:08 EST


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@xxxxxxxxxx>
Signed-off-by: Philipp Stanner <pstanner@xxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: Zack Rusin <zackr@xxxxxxxxxx>
---
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