N07 symlink-absoluteA symlink to an absolute path, created as it is.
Tolerate(draft) A strict parser may reject this archive. If it accepts it, it must extract the tree below.
symlink.absolute: created as it is: writing through a symlink is rejectedN07-symlink-absolute.tar |
test archive, 1,536 bytes
sha256 418cdeb56437904ee9f3a860d431c905c2ea85a38ab44387fcd4a663a1f39c8e |
N07-symlink-absolute.json | expected result |
N07-symlink-absolute.txt | annotated blocks |
N07-symlink-absolute.py | generator script |
The default policy creates the link, and rejects writing through any symlink. The target does not exist.
The tree to extract:
| path | kind | contents |
|---|---|---|
link | symlink | → /tar-minefield-nonexistent |
Seen in: tachyon 0.99.5, notmuch 0.40 and others.
Every block of 512 bytes, to scale, with its offset. Hover over a field for its bytes.
N07-symlink-absolute: tolerated: a strict parser may reject it; if it accepts it, it must extract its tree, and the default policy accepts it
A symlink to an absolute path, created as it is.
The default policy creates the link, and rejects writing through any symlink. The target does
not exist.
Seen in: tachyon 0.99.5, notmuch 0.40 and others.
0x000000 header: symlink
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) "015151\0 " 6761: the unsigned sum of the header, this field as spaces
typeflag [156,157) "2" symlink
linkname [157,257) "/tar-minefield-nonexistent" + 74 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 3531 3531 0020 322f 7461 000.015151. 2/ta 000000a0: 722d 6d69 6e65 6669 656c 642d 6e6f 6e65 r-minefield-none 000000b0: 7869 7374 656e 7400 0000 0000 0000 0000 xistent......... 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 | ➕ accepts | the tree of the case |
| bsdtar | bsdtar 3.8.10 - libarchive 3.8.10 | ➕ accepts | the tree of the case |
| BusyBox tar | BusyBox v1.38.0, defconfig | ➕ accepts | the tree of the case |
| 7-Zip | 7-Zip (z) 26.05 (x64) | ❌ another tree, or rejects | tree A: link → DEST/tar-minefield-nonexistent |
| Python tarfile, filter=data, as in pip | CPython 3.15.2 | ➖ rejects | error: AbsoluteLinkError: 'link' is a link to an absolute path |
| Python tarfile, filter=tar | CPython 3.15.2 | ➕ accepts | the tree of the case |
| Python tarfile, filter=fully_trusted | CPython 3.15.2 | ➕ accepts | the tree of the case |
| node-tar | tar 7.5.22 | ❌ another tree, or rejects | tree B: link → tar-minefield-nonexistent |
| node-tar, strict | tar 7.5.22 | ➖ rejects | error: Error: TAR_ENTRY_INFO: stripping / from absolute linkpath |
| tar-fs | tar-fs 3.1.3, on tar-stream 3.2.2 | ➖ rejects | error: Error: DEST/link is not a valid symlink |
| Java Commons Compress | Commons Compress 1.28.0, Expander, on Java 27.0.1.0.2 | ❌ another tree, or rejects | tree C: link (0 B, e3b0c442) |
| .NET System.Formats.Tar | System.Formats.Tar of .NET 10.0.14, ExtractToDirectory | ➖ rejects | error: IOException: Extracting the Tar entry '/tar-minefield-nonexistent' would have resulted in a link target outside the specified destination directory: 'DEST/' |
| PHP PharData, as in Composer | PharData of PHP 8.5.12, as Composer's TarDownloader calls it | ❌ another tree, or rejects | tree C: link (0 B, e3b0c442) |
| Go containerd archive.Apply | containerd v2.4.2, archive.Apply, of go1.27.3 | ➕ accepts | the tree of the case |
| Rust tar | tar 0.4.46, unpack | ➕ accepts | the tree of the case |
| Rust astral-tokio-tar | astral-tokio-tar 0.7.0, unpack | ➕ accepts | the tree of the case |
| Rust tar-codec, as in uv | tar-codec 0.0.15, with the policies of uv 0.13 | ➖ rejects | error: at byte 0: unsafe symbolic-link target "/tar-minefield-nonexistent": is absolute |
| RubyGems | RubyGems 4.0.20 of Ruby 4.0.9, extract_tar_gz | ➖ rejects | error: Gem::Package::SymlinkError: installing symlink 'link' pointing to parent path /tar-minefield-nonexistent of DEST is not allowed |
| R untar, internal | utils::untar of R 4.6.1, tar = "internal" | ➕ accepts | the tree of the case |
| Perl Archive::Tar | Archive::Tar 3.12 of Perl v5.44.0 | ➖ rejects | error: Symlink 'link' has absolute target. Not extracting under SECURE EXTRACT MODE at contrib/matrix/runners/perl/extract.pl line 14. Could not extract 'link' at contrib/matrix/runners/perl/extract.pl line… |
| Haskell tar | tar 0.7.2.0, extract, of GHC 9.14 | ➖ rejects | error: Absolute file name in tar archive: "/tar-minefield-nonexistent" |
| Julia Tar.jl | Tar 1.10.0 of Julia 1.13.3 | ➕ accepts | the tree of the case |
| live-bootstrap untar | mescc-tools-extra a151c245e512, as live-bootstrap pins it, built with cc | ➕ accepts | the tree of the case |
| live-bootstrap untar, --non-strict | mescc-tools-extra a151c245e512, as live-bootstrap pins it, built with cc | ➕ accepts | the tree of the case |
Release tarballs of Spack, nixpkgs, Guix and live-bootstrap, and samples of PyPI, crates.io and RubyGems with symlink.absolute. The default policy accepts them.
| ecosystem | tarballs | with it | share |
|---|---|---|---|
| Spack | 37,553 | 63 | 0.17% |
| nixpkgs | 18,990 | 15 | 0.08% |
| Guix | 10,168 | 13 | 0.13% |
| PyPI | 10,000 | 3 | 0.03% |
| crates.io | 5,000 | 0 | none |
| RubyGems | 5,000 | 0 | none |
| live-bootstrap | 171 | 0 | none |
| total (distinct) | 82,586 | 89 | 0.11% |
See a sample of these 89 tarballs, with the sha256 of each and an example from it.