N25 symlink-empty-targetA symlink with an empty target.
Reject(draft) A strict parser must reject this archive.
N25-symlink-empty-target.tar |
test archive, 1,536 bytes
sha256 0df78d0114ab31f251cb9d4d716de1c083274ff2a93cb80ccd161a8da342de7e |
N25-symlink-empty-target.json | expected result |
N25-symlink-empty-target.txt | annotated blocks |
N25-symlink-empty-target.py | generator script |
The member link is a symlink whose linkname field is empty, and there is no pax linkpath. A symlink to the empty string cannot be created on most systems. This case is ambiguous because POSIX says only that the contents of a symlink are stored in its linkname field, which leaves room for interpretation of what an empty name means.
Decision point: whether a link with an empty target is a link.
Seen in: none of the scanned tarballs.
Every block of 512 bytes, to scale, with its offset. Hover over a field for its bytes.
N25-symlink-empty-target: must reject
A symlink with an empty target.
The member `link` is a symlink whose linkname field is empty, and there is no pax `linkpath`. A
symlink to the empty string cannot be created on most systems. This case is ambiguous because POSIX
says only that the contents of a symlink are stored in its linkname field, which leaves room for
interpretation of what an empty name means.
Decision point: whether a link with an empty target is a link.
Seen in: none of the scanned tarballs.
0x000000 header: symlink, a symlink whose target is empty
name [ 0,100) "link" + 96 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) "010055\0 " 4141: 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
0x000200 2 zero blocks: the end-of-archive marker
0x000600 end of file
As xxd writes it: xxd -r makes the archive of it.
00000000: 6c69 6e6b 0000 0000 0000 0000 0000 0000 link............ 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 3031 3030 3535 0020 3200 0000 000.010055. 2... 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: 0000 0000 0000 0000 0000 0000 0000 0000 ................ 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 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: 0000 0000 0000 0000 0000 0000 0000 0000 ................ 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 ................
| implementation | version | outcome | what it makes of it |
|---|---|---|---|
| GNU tar | tar (GNU tar) 1.35 | ✅ as the verdict says | error: tar: link: Cannot create symlink to ‘’: No such file or directory tar: Exiting with failure status due to previous errors |
| bsdtar | bsdtar 3.8.10 - libarchive 3.8.10 | ✅ as the verdict says | error: link: Can't create 'link': No such file or directory bsdtar: Error exit delayed from previous errors |
| BusyBox tar | BusyBox v1.38.0, defconfig | ⚠️ crashes | killed by SIGSEGV |
| 7-Zip | 7-Zip (z) 26.05 (x64) | ⚠️ accepts | tree A: link (0 B, e3b0c442) |
| Python tarfile, filter=data, as in pip | CPython 3.15.2 | ⚠️ accepts | tree B: link → . |
| Python tarfile, filter=tar | CPython 3.15.2 | ⚠️ accepts | tree C: nothing |
| Python tarfile, filter=fully_trusted | CPython 3.15.2 | ⚠️ accepts | tree C: nothing |
| node-tar | tar 7.5.22 | ✅ as the verdict says | error: Error: TAR_BAD_ARCHIVE: Unrecognized archive format |
| node-tar, strict | tar 7.5.22 | ✅ as the verdict says | error: Error: TAR_ENTRY_INVALID: linkpath required |
| tar-fs | tar-fs 3.1.3, on tar-stream 3.2.2 | ⚠️ crashes | TypeError [ERR_INVALID_ARG_TYPE]: The "paths[1]" argument must be of type string. Received null |
| Java Commons Compress | Commons Compress 1.28.0, Expander, on Java 27.0.1.0.2 | ⚠️ accepts | tree A: link (0 B, e3b0c442) |
| .NET System.Formats.Tar | System.Formats.Tar of .NET 10.0.14, ExtractToDirectory | ✅ as the verdict says | error: ArgumentException: The value cannot be an empty string. (Parameter 'pathToTarget') |
| PHP PharData, as in Composer | PharData of PHP 8.5.12, as Composer's TarDownloader calls it | ⚠️ accepts | tree A: link (0 B, e3b0c442) |
| Go containerd archive.Apply | containerd v2.4.2, archive.Apply, of go1.27.3 | ✅ as the verdict says | error: symlink DEST/link: no such file or directory |
| Rust tar | tar 0.4.46, unpack | ✅ as the verdict says | error: failed to unpack `DEST/link` |
| Rust astral-tokio-tar | astral-tokio-tar 0.7.0, unpack | ✅ as the verdict says | error: failed to unpack `DEST/link` |
| Rust tar-codec, as in uv | tar-codec 0.0.15, with the policies of uv 0.13 | ✅ as the verdict says | error: at byte 0: invalid link link -> "": link target is empty |
| RubyGems | RubyGems 4.0.20 of Ruby 4.0.9, extract_tar_gz | ✅ as the verdict says | error: Gem::Package::SymlinkError: installing symlink 'link' pointing to parent path DEST of DEST is not allowed |
| R untar, internal | utils::untar of R 4.6.1, tar = "internal" | ⚠️ crashes | argument 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::Tar | Archive::Tar 3.12 of Perl v5.44.0 | ✅ as the verdict says | error: Making symbolic link 'DEST/link' to '' failed at contrib/matrix/runners/perl/extract.pl line 14. Could not extract 'link' at contrib/matrix/runners/perl/extract.pl line 14. Could not extract 'link' |
| Haskell tar | tar 0.7.2.0, extract, of GHC 9.14 | ✅ as the verdict says | error: createDirectoryLink:createSymbolicLink '' to 'DEST/link': does not exist (No such file or directory) |
| Julia Tar.jl | Tar 1.10.0 of Julia 1.13.3 | ✅ as the verdict says | error: symlink with empty link path Tar.Header("link", :symlink, 0o644, 0, "") |
| live-bootstrap untar | mescc-tools-extra a151c245e512, as live-bootstrap pins it, built with cc | ✅ as the verdict says | error: Failed to create symlink |
| live-bootstrap untar, --non-strict | mescc-tools-extra a151c245e512, as live-bootstrap pins it, built with cc | ⚠️ accepts | tree C: nothing |
Release tarballs of Spack, nixpkgs, Guix and live-bootstrap, and samples of PyPI, crates.io and RubyGems with symlink.empty-target.
| ecosystem | tarballs | with it | share |
|---|---|---|---|
| Spack | 37,553 | 0 | none |
| nixpkgs | 18,990 | 0 | none |
| Guix | 10,168 | 0 | none |
| PyPI | 10,000 | 0 | none |
| crates.io | 5,000 | 0 | none |
| RubyGems | 5,000 | 0 | none |
| live-bootstrap | 171 | 0 | none |
| total (distinct) | 82,586 | 0 | none |