Working draft

S05 hardlink-to-later-member

A hardlink to a member that comes later.

Reject(draft) A strict parser must reject this archive.

Category
order and state
Default policy
rejects it
Files
S05-hardlink-to-later-member.tar test archive, 2,560 bytes sha256 8639bd97f23f124bce2f22eb102910a0cbb2fa09cca3a93573165fa440d9f7f5
S05-hardlink-to-later-member.jsonexpected result
S05-hardlink-to-later-member.txtannotated blocks
S05-hardlink-to-later-member.pygenerator script

The case

The member h is a hardlink to f, which comes after it. In POSIX, the target of a hardlink is a file previously archived. Read leniently, this case is ambiguous because h either has nothing to link to yet, or is linked to f once the whole archive is read; a reader may also make it an empty file.

Decision point: whether the target of a hardlink can be a later member.

Seen in: none of the scanned tarballs.

The archive

Every block of 512 bytes, to scale, with its offset. Hover over a field for its bytes.

S05-hardlink-to-later-member: every block of the archive0x000000header: hardlinkname [0,100): "h" + 99 NULnamemode [100,108): "0000644" + NUL, 644 (octal)uid [108,116): "0000000" + NUL, 0gid [116,124): "0000000" + NUL, 0size [124,136): "00000000000" + NUL, 0mtime [136,148): "00000000000" + NUL, 0chksum [148,156): "007514\0 ", 3916: the unsigned sum of the header, this field as spacestypeflag [156,157): "1", hardlinklinkname [157,257): "f" + 99 NULlinknamemagic [257,263): "ustar" + NULversion [263,265): "00"uname [265,297): 32 NULunamegname [297,329): 32 NULgnamedevmajor [329,337): "0000000" + NUL, 0devminor [337,345): "0000000" + NUL, 0prefix [345,500): 155 NULprefixpad [500,512): 12 NULname "h" + 99 NULlinkname "f" + 99 NUL0x000200header: regular filename [0,100): "f" + 99 NULnamemode [100,108): "0000644" + NUL, 644 (octal)uid [108,116): "0000000" + NUL, 0gid [116,124): "0000000" + NUL, 0size [124,136): "00000000002" + NUL, 2mtime [136,148): "00000000000" + NUL, 0chksum [148,156): "007345\0 ", 3813: the unsigned sum of the header, this field as spacestypeflag [156,157): "0", regular filelinkname [157,257): 100 NULlinknamemagic [257,263): "ustar" + NULversion [263,265): "00"uname [265,297): 32 NULunamegname [297,329): 32 NULgnamedevmajor [329,337): "0000000" + NUL, 0devminor [337,345): "0000000" + NUL, 0prefix [345,500): 155 NULprefixpad [500,512): 12 NULname "f" + 99 NUL0x000400data2 bytes, then 510 NUL to the end of the block; "f\n""f\n"0x0006002 zero blocks: the end-of-archive markerbytes 0 to 512 of 1024: 512 NUL0x0008002 zero blocks, continuedbytes 512 to 1024 of 1024: 512 NUL0x000a00end of fileNULprintable ASCIIspacecontrol character, such as a newlinebyte over 0x7fwritten by the case itself
Every block, as text 
S05-hardlink-to-later-member: must reject

A hardlink to a member that comes later.

The member `h` is a hardlink to `f`, which comes after it. In POSIX, the target of a hardlink is a
file previously archived. Read leniently, this case is ambiguous because `h` either has nothing to
link to yet, or is linked to `f` once the whole archive is read; a reader may also make it an
empty file.

Decision point: whether the target of a hardlink can be a later member.
Seen in: none of the scanned tarballs.

0x000000  header: hardlink
          name     [  0,100)  "h" + 99 NUL
          mode     [100,108)  "0000644" + NUL  644 (octal)
          uid      [108,116)  "0000000" + NUL  0
          gid      [116,124)  "0000000" + NUL  0
          size     [124,136)  "00000000000" + NUL  0
          mtime    [136,148)  "00000000000" + NUL  0
          chksum   [148,156)  "007514\0 "  3916: the unsigned sum of the header, this field as spaces
          typeflag [156,157)  "1"  hardlink
          linkname [157,257)  "f" + 99 NUL
          magic    [257,263)  "ustar" + NUL
          version  [263,265)  "00"
          uname    [265,297)  32 NUL
          gname    [297,329)  32 NUL
          devmajor [329,337)  "0000000" + NUL  0
          devminor [337,345)  "0000000" + NUL  0
          prefix   [345,500)  155 NUL
          pad      [500,512)  12 NUL
0x000200  header: regular file
          name     [  0,100)  "f" + 99 NUL
          mode     [100,108)  "0000644" + NUL  644 (octal)
          uid      [108,116)  "0000000" + NUL  0
          gid      [116,124)  "0000000" + NUL  0
          size     [124,136)  "00000000002" + NUL  2
          mtime    [136,148)  "00000000000" + NUL  0
          chksum   [148,156)  "007345\0 "  3813: the unsigned sum of the header, this field as spaces
          typeflag [156,157)  "0"  regular file
          linkname [157,257)  100 NUL
          magic    [257,263)  "ustar" + NUL
          version  [263,265)  "00"
          uname    [265,297)  32 NUL
          gname    [297,329)  32 NUL
          devmajor [329,337)  "0000000" + NUL  0
          devminor [337,345)  "0000000" + NUL  0
          prefix   [345,500)  155 NUL
          pad      [500,512)  12 NUL
0x000400  data
          2 bytes, then 510 NUL to the end of the block
          "f\n"
0x000600  2 zero blocks: the end-of-archive marker
0x000a00  end of file
Every byte, as a hex dump

As xxd writes it: xxd -r makes the archive of it.

00000000: 6800 0000 0000 0000 0000 0000 0000 0000  h...............
00000010: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000020: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000030: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000040: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000050: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000060: 0000 0000 3030 3030 3634 3400 3030 3030  ....0000644.0000
00000070: 3030 3000 3030 3030 3030 3000 3030 3030  000.0000000.0000
00000080: 3030 3030 3030 3000 3030 3030 3030 3030  0000000.00000000
00000090: 3030 3000 3030 3735 3134 0020 3166 0000  000.007514. 1f..
000000a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000000b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000000c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000000d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000000e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000000f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000100: 0075 7374 6172 0030 3000 0000 0000 0000  .ustar.00.......
00000110: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000120: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000130: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000140: 0000 0000 0000 0000 0030 3030 3030 3030  .........0000000
00000150: 0030 3030 3030 3030 0000 0000 0000 0000  .0000000........
00000160: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000170: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000180: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000190: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000200: 6600 0000 0000 0000 0000 0000 0000 0000  f...............
00000210: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000220: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000230: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000240: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000250: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000260: 0000 0000 3030 3030 3634 3400 3030 3030  ....0000644.0000
00000270: 3030 3000 3030 3030 3030 3000 3030 3030  000.0000000.0000
00000280: 3030 3030 3030 3200 3030 3030 3030 3030  0000002.00000000
00000290: 3030 3000 3030 3733 3435 0020 3000 0000  000.007345. 0...
000002a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000002b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000002c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000002d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000002e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000002f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000300: 0075 7374 6172 0030 3000 0000 0000 0000  .ustar.00.......
00000310: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000320: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000330: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000340: 0000 0000 0000 0000 0030 3030 3030 3030  .........0000000
00000350: 0030 3030 3030 3030 0000 0000 0000 0000  .0000000........
00000360: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000370: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000380: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000390: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000003a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000003b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000003c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000003d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000003e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000003f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000400: 660a 0000 0000 0000 0000 0000 0000 0000  f...............
00000410: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000420: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000430: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000440: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000450: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000460: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000470: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000480: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000490: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000004a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000004b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000004c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000004d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000004e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000004f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000500: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000510: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000520: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000530: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000540: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000550: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000560: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000570: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000580: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000590: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000005a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000005b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000005c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000005d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000005e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000005f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000600: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000610: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000620: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000630: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000640: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000650: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000660: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000670: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000680: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000690: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000006a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000006b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000006c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000006d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000006e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000006f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000700: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000710: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000720: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000730: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000740: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000750: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000760: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000770: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000780: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000790: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000007a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000007b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000007c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000007d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000007e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000007f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000800: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000810: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000820: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000830: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000840: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000850: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000860: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000870: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000880: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000890: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000008a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000008b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000008c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000008d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000008e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000008f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000900: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000910: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000920: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000930: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000940: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000950: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000960: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000970: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000980: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000990: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000009a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000009b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000009c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000009d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000009e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000009f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................

What implementations make of it

implementationversionoutcomewhat it makes of it
GNU tartar (GNU tar) 1.35✅ as the verdict sayserror: tar: h: Cannot hard link to ‘f’: No such file or directory tar: Exiting with failure status due to previous errors
bsdtarbsdtar 3.8.10 - libarchive 3.8.10✅ as the verdict sayserror: h: Hard-link target 'f' does not exist: No such file or directory bsdtar: Error exit delayed from previous errors
BusyBox tarBusyBox v1.38.0, defconfig⚠️ acceptstree A: f (2 B, 092fcfbb), h (2 B, 092fcfbb)
7-Zip7-Zip (z) 26.05 (x64)⚠️ acceptstree A: f (2 B, 092fcfbb), h (2 B, 092fcfbb)
Python tarfile, filter=data, as in pipCPython 3.15.2✅ as the verdict sayserror: KeyError: "linkname 'f' not found"
Python tarfile, filter=tarCPython 3.15.2✅ as the verdict sayserror: KeyError: "linkname 'f' not found"
Python tarfile, filter=fully_trustedCPython 3.15.2✅ as the verdict sayserror: KeyError: "linkname 'f' not found"
node-tartar 7.5.22⚠️ acceptstree B: f (2 B, 092fcfbb)
node-tar, stricttar 7.5.22✅ as the verdict sayserror: Error: ENOENT: no such file or directory, link 'DEST/f' -> 'DEST/h'
tar-fstar-fs 3.1.3, on tar-stream 3.2.2✅ as the verdict sayserror: Error: DEST/h is not a valid hardlink
Java Commons CompressCommons Compress 1.28.0, Expander, on Java 27.0.1.0.2⚠️ acceptstree C: f (2 B, 092fcfbb), h (0 B, e3b0c442)
.NET System.Formats.TarSystem.Formats.Tar of .NET 10.0.14, ExtractToDirectory✅ as the verdict sayserror: FileNotFoundException: Could not find file 'DEST/h'.
PHP PharData, as in ComposerPharData of PHP 8.5.12, as Composer's TarDownloader calls it✅ as the verdict sayserror: UnexpectedValueException: phar error: "suite/archives/S05-hardlink-to-later-member.tar" is a corrupted tar file - hard link to non-existent file "f"
Go containerd archive.Applycontainerd v2.4.2, archive.Apply, of go1.27.3✅ as the verdict sayserror: link DEST/f DEST/h: no such file or directory
Rust tartar 0.4.46, unpack✅ as the verdict sayserror: failed to unpack `DEST/h`
Rust astral-tokio-tarastral-tokio-tar 0.7.0, unpack✅ as the verdict sayserror: failed to unpack `DEST/h`
Rust tar-codec, as in uvtar-codec 0.0.15, with the policies of uv 0.13✅ as the verdict sayserror: at byte 0: invalid link h -> "f": hard-link target is not a previously extracted file
RubyGemsRubyGems 4.0.20 of Ruby 4.0.9, extract_tar_gz⚠️ acceptstree B: f (2 B, 092fcfbb)
R untar, internalutils::untar of R 4.6.1, tar = "internal"⚠️ acceptstree B: f (2 B, 092fcfbb)
Perl Archive::TarArchive::Tar 3.12 of Perl v5.44.0⚠️ acceptstree A: f (2 B, 092fcfbb), h (2 B, 092fcfbb)
Haskell tartar 0.7.2.0, extract, of GHC 9.14⚠️ acceptstree A: f (2 B, 092fcfbb), h (2 B, 092fcfbb)
Julia Tar.jlTar 1.10.0 of Julia 1.13.3✅ as the verdict sayserror: Tarball contains hardlink with non-existent target: - path = "h" - target = "f" Refusing to extract — possible attack!
live-bootstrap untarmescc-tools-extra a151c245e512, as live-bootstrap pins it, built with cc✅ as the verdict sayserror: unable to create hardlinks
live-bootstrap untar, --non-strictmescc-tools-extra a151c245e512, as live-bootstrap pins it, built with cc⚠️ acceptstree B: f (2 B, 092fcfbb)

Prevalence in release tarballs

Release tarballs of Spack, nixpkgs, Guix and live-bootstrap, and samples of PyPI, crates.io and RubyGems with hardlink.to-later-member.

ecosystemtarballswith itshare
Spack37,5530none
nixpkgs18,9900none
Guix10,1680none
PyPI10,0000none
crates.io5,0000none
RubyGems5,0000none
live-bootstrap1710none
total (distinct)82,5860none