nvmet-loop: fix possible leakage during error flow

During nvme_loop_queue_rq error flow, one must call nvme_cleanup_cmd since
it's symmetric to nvme_setup_cmd.

Signed-off-by: Max Gurtovoy <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Keith Busch <[email protected]>

Author: Max Gurtovoy

drivers/nvme/target/loop.c

@@ -157,8 +157,10 @@ static blk_status_t nvme_loop_queue_rq(struct blk_mq_hw_ctx *hctx,
 		iod->sg_table.sgl = iod->first_sgl;
 		if (sg_alloc_table_chained(&iod->sg_table,
 				blk_rq_nr_phys_segments(req),
-				iod->sg_table.sgl, SG_CHUNK_SIZE))
+				iod->sg_table.sgl, SG_CHUNK_SIZE)) {
+			nvme_cleanup_cmd(req);
 			return BLK_STS_RESOURCE;
+		}
 
 		iod->req.sg = iod->sg_table.sgl;
 		iod->req.sg_cnt = blk_rq_map_sg(req->q, req, iod->sg_table.sgl);