drm/i915: Fix memory leaks in scatterlist

This patch fixes memory leaks on error escapes in i915_scatterlist.c

Fixes: c3bfba9a ("drm/i915: Check for integer truncation on scatterlist creation")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Matt Atwood <matthew.s.atwood@intel.com>
Reviewed-by: Harish Chegondi <harish.chegondi@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230201232801.123684-1-matthew.s.atwood@intel.com
(cherry picked from commit 389b9d91)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

drivers/gpu/drm/i915/i915_scatterlist.c

@@ -98,8 +98,10 @@ struct i915_refct_sgt *i915_rsgt_from_mm_node(const struct drm_mm_node *node,
 	st = &rsgt->table;
 	/* restricted by sg_alloc_table */
 	if (WARN_ON(overflows_type(DIV_ROUND_UP_ULL(node->size, segment_pages),
-				   unsigned int)))
+				   unsigned int))) {
+		i915_refct_sgt_put(rsgt);
 		return ERR_PTR(-E2BIG);
+	}
 
 	if (sg_alloc_table(st, DIV_ROUND_UP_ULL(node->size, segment_pages),
 			   GFP_KERNEL)) {
@@ -183,8 +185,10 @@ struct i915_refct_sgt *i915_rsgt_from_buddy_resource(struct ttm_resource *res,
 	i915_refct_sgt_init(rsgt, size);
 	st = &rsgt->table;
 	/* restricted by sg_alloc_table */
-	if (WARN_ON(overflows_type(PFN_UP(res->size), unsigned int)))
+	if (WARN_ON(overflows_type(PFN_UP(res->size), unsigned int))) {
+		i915_refct_sgt_put(rsgt);
 		return ERR_PTR(-E2BIG);
+	}
 
 	if (sg_alloc_table(st, PFN_UP(res->size), GFP_KERNEL)) {
 		i915_refct_sgt_put(rsgt);