diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c
index df86fb4..a81c10f 100644
--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -392,7 +392,8 @@
 
 		sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
 		sg = sgl->sg;
-		sg_unmark_end(sg + sgl->cur);
+		if (sgl->cur)
+			sg_unmark_end(sg + sgl->cur - 1);
 		do {
 			i = sgl->cur;
 			plen = min_t(size_t, len, PAGE_SIZE);