mkfs.bfs: fix memory leaks and weak code

- use size_t to store strlen() result
- init superblock with the default volume and fsname
- don't use strdup(), it's unnecessary as getopt_long() does not
  modify arguments
- don't use memcpy() as we need to check string sizes
- restrict verbose output 6 bytes

Addresses: https://github.com/util-linux/util-linux/pull/3488
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/disk-utils/mkfs.bfs.c b/disk-utils/mkfs.bfs.c
index 895a1f27b7a5c242b60a1571fca8129f3c308d98..d18589ab288f6f7d7ff095226d89f811001a5ab6 100644 (file)
--- a/disk-utils/mkfs.bfs.c
+++ b/disk-utils/mkfs.bfs.c
@@ -103,7 +103,7 @@ static void __attribute__((__noreturn__)) usage(void)
 
 int main(int argc, char **argv)
 {
-       char *device, *volume, *fsname;
+       char *device, *volume = NULL, *fsname = NULL;
        char *lockmode = 0;
        long inodes;
        unsigned long long total_blocks, ino_bytes, ino_blocks, data_blocks;
@@ -111,12 +111,16 @@ int main(int argc, char **argv)
        int verbose = 0;
        int fd;
        uint32_t first_block;
-       struct bfssb sb;
        struct bfsi ri;
        struct bfsde de;
        struct stat statbuf;
        time_t now;
-       int c, i, len;
+       int c, i;
+       size_t len;
+       struct bfssb sb = {
+               .s_fsname = "\x20\x20\x20\x20\x20\x20",
+               .s_volume = "\x20\x20\x20\x20\x20\x20"
+       };
 
        enum {
            VERSION_OPTION = CHAR_MAX + 1,
@@ -145,7 +149,6 @@ int main(int argc, char **argv)
        if (argc == 2 && !strcmp(argv[1], "-V"))
                print_version(EXIT_SUCCESS);
 
-       volume = fsname = "      ";     /* is there a default? */
        inodes = 0;
 
        while ((c = getopt_long(argc, argv, "N:V:F:vhcl", longopts, NULL)) != -1) {
@@ -155,17 +158,21 @@ int main(int argc, char **argv)
                        break;
 
                case 'V':
+                       if (volume)
+                               errx(EXIT_FAILURE, _("more than one volume"));
                        len = strlen(optarg);
-                       if (len <= 0 || len > 6)
+                       if (!len || len > sizeof(sb.s_volume))
                                errx(EXIT_FAILURE, _("volume name too long"));
-                       volume = xstrdup(optarg);
+                       volume = optarg;
                        break;
 
                case 'F':
+                       if (fsname)
+                               errx(EXIT_FAILURE, _("more than one fsname"));
                        len = strlen(optarg);
-                       if (len <= 0 || len > 6)
+                       if (!len || len > sizeof(sb.s_fsname))
                                errx(EXIT_FAILURE, _("fsname name too long"));
-                       fsname = xstrdup(optarg);
+                       fsname = optarg;
                        break;
 
                case 'v':
@@ -260,13 +267,16 @@ int main(int argc, char **argv)
        sb.s_start = cpu_to_le32(ino_bytes + sizeof(struct bfssb));
        sb.s_end = cpu_to_le32(total_blocks * BFS_BLOCKSIZE - 1);
        sb.s_from = sb.s_to = sb.s_backup_from = sb.s_backup_to = -1;
-       memcpy(sb.s_fsname, fsname, 6);
-       memcpy(sb.s_volume, volume, 6);
+
+       if (fsname)
+               str2memcpy(sb.s_fsname, fsname, sizeof(sb.s_fsname));
+       if (volume)
+               str2memcpy(sb.s_volume, volume, sizeof(sb.s_volume));
 
        if (verbose) {
                fprintf(stderr, _("Device: %s\n"), device);
-               fprintf(stderr, _("Volume: <%-6s>\n"), volume);
-               fprintf(stderr, _("FSname: <%-6s>\n"), fsname);
+               fprintf(stderr, _("Volume: <%.6s>\n"), sb.s_volume);
+               fprintf(stderr, _("FSname: <%.6s>\n"), sb.s_fsname);
                fprintf(stderr, _("BlockSize: %d\n"), BFS_BLOCKSIZE);
                if (ino_blocks == 1)
                        fprintf(stderr, _("Inodes: %ld (in 1 block)\n"),