diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 7f836f8f9db1..3ee84604e36d 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -1377,7 +1377,7 @@ static int hugetlbfs_parse_param(struct fs_context *fc, struct fs_parameter *par
 
 	case Opt_size:
 		/* memparse() will accept a K/M/G without a digit */
-		if (!isdigit(param->string[0]))
+		if (!param->string || !isdigit(param->string[0]))
 			goto bad_val;
 		ctx->max_size_opt = memparse(param->string, &rest);
 		ctx->max_val_type = SIZE_STD;
@@ -1387,7 +1387,7 @@ static int hugetlbfs_parse_param(struct fs_context *fc, struct fs_parameter *par
 
 	case Opt_nr_inodes:
 		/* memparse() will accept a K/M/G without a digit */
-		if (!isdigit(param->string[0]))
+		if (!param->string || !isdigit(param->string[0]))
 			goto bad_val;
 		ctx->nr_inodes = memparse(param->string, &rest);
 		return 0;
@@ -1403,7 +1403,7 @@ static int hugetlbfs_parse_param(struct fs_context *fc, struct fs_parameter *par
 
 	case Opt_min_size:
 		/* memparse() will accept a K/M/G without a digit */
-		if (!isdigit(param->string[0]))
+		if (!param->string || !isdigit(param->string[0]))
 			goto bad_val;
 		ctx->min_size_opt = memparse(param->string, &rest);
 		ctx->min_val_type = SIZE_STD;