Working draft

N46 pax-linkpath-linkname-empty

A symlink with an empty linkname field and a pax linkpath.

Accept(draft) Every implementation must accept this archive, and extract the expected tree below.

Category
name
Default policy
accepts it
Files
N46-pax-linkpath-linkname-empty.tar test archive, 2,560 bytes sha256 497def34466bf29220486e8e1b5e5741f0e2fdb71cd6b8df16b647ccd5b86ff0
N46-pax-linkpath-linkname-empty.jsonexpected result
N46-pax-linkpath-linkname-empty.txtannotated blocks
N46-pax-linkpath-linkname-empty.pygenerator script

The case

The archive has a symlink, of typeflag 2, with the name l and an empty linkname field. Its pax header has linkpath=target.

The pax linkpath overrides the linkname field, so the empty field is not used, and l points to target.

The expected tree:

pathkindcontents
lsymlink→ target

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.

N46-pax-linkpath-linkname-empty: every block of the archive0x000000header: pax extended headername [0,100): "PaxHeader" + 91 NULnamemode [100,108): "0000644" + NUL, 644 (octal)uid [108,116): "0000000" + NUL, 0gid [116,124): "0000000" + NUL, 0size [124,136): "00000000023" + NUL, 19mtime [136,148): "00000000000" + NUL, 0chksum [148,156): "011074\0 ", 4668: the unsigned sum of the header, this field as spacestypeflag [156,157): "x", pax extended headerlinkname [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 "PaxHeader" + 91 NUL0x000200data: pax records19 bytes of pax records, then 493 NUL; "19 linkpath=target\n""19 linkpath=target\n"0x000400header: symlink, an empty linkname fieldname [0,100): "l" + 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): "007353\0 ", 3819: the unsigned sum of the header, this field as spacestypeflag [156,157): "2", symlinklinkname [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 "l" + 99 NULlinkname 100 NUL0x0006002 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 
N46-pax-linkpath-linkname-empty: must accept, and extract its tree

A symlink with an empty linkname field and a pax `linkpath`.

The archive has a symlink, of typeflag `2`, with the name `l` and an empty linkname field. Its pax
header has `linkpath=target`.

The pax `linkpath` overrides the linkname field, so the empty field is not used, and
`l` points to `target`.

Seen in: none of the scanned tarballs.
See also: N34, an empty pax `linkpath`.

0x000000  header: pax extended header
          name     [  0,100)  "PaxHeader" + 91 NUL
          mode     [100,108)  "0000644" + NUL  644 (octal)
          uid      [108,116)  "0000000" + NUL  0
          gid      [116,124)  "0000000" + NUL  0
          size     [124,136)  "00000000023" + NUL  19
          mtime    [136,148)  "00000000000" + NUL  0
          chksum   [148,156)  "011074\0 "  4668: the unsigned sum of the header, this field as spaces
          typeflag [156,157)  "x"  pax extended header
          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
0x000200  data: pax records
          19 bytes of pax records, then 493 NUL
          "19 linkpath=target\n"
0x000400  header: symlink, an empty linkname field
          name     [  0,100)  "l" + 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)  "007353\0 "  3819: the unsigned sum of the header, this field as spaces
          typeflag [156,157)  "2"  symlink
          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
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: 5061 7848 6561 6465 7200 0000 0000 0000  PaxHeader.......
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 3032 3300 3030 3030 3030 3030  0000023.00000000
00000090: 3030 3000 3031 3130 3734 0020 7800 0000  000.011074. x...
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: 3139 206c 696e 6b70 6174 683d 7461 7267  19 linkpath=targ
00000210: 6574 0a00 0000 0000 0000 0000 0000 0000  et..............
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 0000 0000 0000 0000 0000 0000  ................
00000270: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000280: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000290: 0000 0000 0000 0000 0000 0000 0000 0000  ................
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: 0000 0000 0000 0000 0000 0000 0000 0000  ................
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 0000 0000 0000 0000  ................
00000350: 0000 0000 0000 0000 0000 0000 0000 0000  ................
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: 6c00 0000 0000 0000 0000 0000 0000 0000  l...............
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 3030 3030 3634 3400 3030 3030  ....0000644.0000
00000470: 3030 3000 3030 3030 3030 3000 3030 3030  000.0000000.0000
00000480: 3030 3030 3030 3000 3030 3030 3030 3030  0000000.00000000
00000490: 3030 3000 3030 3733 3533 0020 3200 0000  000.007353. 2...
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: 0075 7374 6172 0030 3000 0000 0000 0000  .ustar.00.......
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 0030 3030 3030 3030  .........0000000
00000550: 0030 3030 3030 3030 0000 0000 0000 0000  .0000000........
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

In the outcome column, ✅ means that the implementation follows the default policy.

implementationversionoutcomewhat it makes of it
GNU tartar (GNU tar) 1.35✅ acceptsthe expected tree
bsdtarbsdtar 3.8.11 - libarchive 3.8.11✅ acceptsthe expected tree
BusyBox tarBusyBox v1.38.0, defconfig✅ acceptsthe expected tree
7-Zip7-Zip (z) 26.05 (x64)✅ acceptsthe expected tree
Python tarfile, filter=data, as in pipCPython 3.15.2✅ acceptsthe expected tree
Python tarfile, filter=tarCPython 3.15.2✅ acceptsthe expected tree
Python tarfile, filter=fully_trustedCPython 3.15.2✅ acceptsthe expected tree
node-tartar 7.5.22❌ another tree, or rejectstree A: nothing
node-tar, stricttar 7.5.22❌ another tree, or rejectserror: Error: TAR_ENTRY_INVALID: linkpath required
tar-fstar-fs 3.1.3, on tar-stream 3.2.2✅ acceptsthe expected tree
Java Commons CompressCommons Compress 1.28.0, Expander, on Java 27.0.1.0.2❌ another tree, or rejectstree B: l (0 B, e3b0c442)
.NET System.Formats.TarSystem.Formats.Tar of .NET 10.0.14, ExtractToDirectory✅ acceptsthe expected tree
PHP PharData, as in ComposerPharData of PHP 8.5.12, as Composer's TarDownloader calls it❌ another tree, or rejectstree B: l (0 B, e3b0c442)
Go containerd archive.Applycontainerd v2.4.2, archive.Apply, of go1.27.3✅ acceptsthe expected tree
Rust tartar 0.4.46, unpack✅ acceptsthe expected tree
Rust astral-tokio-tarastral-tokio-tar 0.7.1, unpack✅ acceptsthe expected tree
Rust tar-codec, as in uvtar-codec 0.0.16, with the policies of uv 0.13✅ acceptsthe expected tree
RubyGemsRubyGems 4.0.20 of Ruby 4.0.9, extract_tar_gz❌ another tree, or rejectserror: Gem::Package::SymlinkError: installing symlink 'l' pointing to parent path DEST of DEST is not allowed
R untar, internalutils::untar of R 4.6.2, tar = "internal"❌ crashesargument must be coercible to non-negative integer Warning message: In max(which(block[158:257] > 0)) : no non-missing arguments to max; returning -Inf
Perl Archive::TarArchive::Tar 3.12 of Perl v5.44.0❌ another tree, or rejectserror: Making symbolic link 'DEST/l' to '' failed at contrib/matrix/runners/perl/extract.pl line 14. Could not extract 'l' at contrib/matrix/runners/perl/extract.pl line 14. Could not extract 'l'
Haskell tartar 0.7.2.0, extract, of GHC 9.14✅ acceptsthe expected tree
Julia Tar.jlTar 1.10.0 of Julia 1.13.3✅ acceptsthe expected tree
live-bootstrap untarmescc-tools-extra a151c245e512, as live-bootstrap pins it❌ another tree, or rejectserror: Failed to create symlink
live-bootstrap untar, --non-strictmescc-tools-extra a151c245e512, as live-bootstrap pins it❌ another tree, or rejectstree C: PaxHeader (19 B, 87ae2727)

Prevalence in release tarballs

This case is not measured in release tarballs: the scan does not report a feature of it on its own.

See also