--- src/sbin/badsect/badsect.c	2005/02/13 19:22:42	1.7
+++ src/sbin/badsect/badsect.c	2005/02/14 19:18:53	1.8
@@ -94,6 +94,7 @@ main(int argc, char **argv)
 {
 	daddr_t diskbn;
 	daddr_t number;
+	dev_t dev;
 	struct stat stbuf, devstat;
 	register struct dirent *dp;
 	DIR *dirp;
@@ -142,12 +143,12 @@ main(int argc, char **argv)
 		 * bit was lost by bogus sign extensions.
 		 */
 		diskbn = dbtofsb(fs, number);
-		if ((daddr_t)((dev_t)diskbn) != diskbn) {
+		dev = (dev_t)diskbn;
+		if ((daddr_t)dev != diskbn) {
 			printf("sector %ld cannot be represented as a dev_t\n",
 			    (long)number);
 			errs++;
-		}
-		else if (mknod(*argv, IFMT|0600, (dev_t)diskbn) < 0) {
+		} else if (mknod(*argv, IFMT | 0600, dev) < 0) {
 			warn("%s", *argv);
 			errs++;
 		}
@@ -163,7 +164,11 @@ chkuse(daddr_t blkno, int cnt)
 	daddr_t fsbn, bn;
 
 	fsbn = dbtofsb(fs, blkno);
-	if ((int32_t)((unsigned)(fsbn+cnt)) > fs->fs_size) {
+	if (fs->fs_size < 0 || fsbn + cnt < 0) {
+		printf("internal error: negative fs size or block number\n");
+		return (1);
+	}
+	if (fsbn + cnt > fs->fs_size) {
 		printf("block %ld out of range of file system\n", (long)blkno);
 		return (1);
 	}