No description
bac38f3c49
Suppose I have a path /nix/store/[hash]-[name]/a/a/a/a/a/[...]/a, long enough that everything after "/nix/store/" is longer than 4096 (MAX_PATH) bytes. Nix will happily allow such a path to be inserted into the store, because it doesn't look at all the nested structure. It just cares about the /nix/store/[hash]-[name] part. But, when the path is deleted, we encounter a problem. Nix will move the path to /nix/store/trash, but then when it's trying to recursively delete the trash directory, it will at some point try to unlink /nix/store/trash/[hash]-[name]/a/a/a/a/a/[...]/a. This will fail, because the path is too long. After this has failed, any store deletion operation will never work again, because Nix needs to delete the trash directory before recreating it to move new things to it. (I assume this is because otherwise a path being deleted could already exist in the trash, and then moving it would fail.) This means that if I can trick somebody into just fetching a tarball containing a path of the right length, they won't be able to delete store paths or garbage collect ever again, until the offending path is manually removed from /nix/store/trash. (And even fixing this manually is quite difficult if you don't understand the issue, because the absolute path that Nix says it failed to remove is also too long for rm(1).) This patch fixes the issue by making Nix's recursive delete operation use unlinkat(2). This function takes a relative path and a directory file descriptor. We ensure that the relative path is always just the name of the directory entry, and therefore its length will never exceed 255 bytes. This means that it will never even come close to AX_PATH, and Nix will therefore be able to handle removing arbitrarily deep directory hierachies. Since the directory file descriptor is used for recursion after being used in readDirectory, I made a variant of readDirectory that takes an already open directory stream, to avoid the directory being opened multiple times. As we have seen from this issue, the less we have to interact with paths, the better, and so it's good to reuse file descriptors where possible. I left _deletePath as succeeding even if the parent directory doesn't exist, even though that feels wrong to me, because without that early return, the linux-sandbox test failed. Reported-by: Alyssa Ross <hi@alyssa.is> Thanks-to: Puck Meerburg <puck@puckipedia.com> Tested-by: Puck Meerburg <puck@puckipedia.com> Reviewed-by: Puck Meerburg <puck@puckipedia.com> (cherry picked from commit c05e20daa1abb3446e378331697938b78af2b3d7) |
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| bin | ||
| docs | ||
| fun | ||
| lisp/dns | ||
| net | ||
| nix | ||
| ops | ||
| overrides | ||
| presentations | ||
| third_party | ||
| tools | ||
| web | ||
| .envrc | ||
| .git-blame-ignore-revs | ||
| .gitignore | ||
| .rgignore | ||
| ci-builds.nix | ||
| default.nix | ||
| LICENSE | ||
| README.md | ||
depot
This repository is the monorepo for my personal tools and infrastructure. Everything in here is built using Nix with an automatic attribute-set layout that mirrors the filesystem layout of the repository (this might feel familiar to users of Bazel).
This repository used to be hosted on GitHub, but for a variety of reasons I have decided to take over the management of personal infrastructure - of which this repository is a core component.
If you've ended up here and have no idea who I am, feel free to follow me on Twitter.
Highlights
Tools
tools/emacscontains my personal Emacs configuration (packages & config)fun/aoc2019contains solutions for a handful of Advent of Code 2019 challenges, before I ran out of interesttools/blog_clicontains my tool for writing new blog posts and storing them in the DNS zonetools/cheddarcontains a source code and Markdown rendering tool that is integrated with my cgit instance to render files in various viewsops/kms_pass.nixis a tiny tool that emulates the user-interface ofpass, but actually uses Google Cloud KMS for secret decryptionops/kontemplatecontains my Kubernetes resource templating tool (with which the services in this repository are deployed!)ops/besadiicontains a tool that runs as the gitpost-receive-hook on my git server to trigger builds on sourcehut.
Packages / Libraries
nix/buildGoimplements a Nix library that can build Go software in the style of Bazel'srules_go. Go programs in this repository are built using this library.nix/buildLispimplements a Nix library that can build Common Lisp software. Currently only SBCL is supported. Lisp programs in this repository are built using this library.tools/emacs-pkgscontains various Emacs libraries that my Emacs setup uses, for example:dottime.elprovides dottime in the Emacs modelinenix-util.elprovides editing utilities for Nix filesterm-switcher.elis an ivy-function for switching between vterm buffers
net/alcoholic_jwtcontains an easy-to-use JWT-validation library for Rustnet/crimpcontains a high-level HTTP client using cURL for Rust
Services
Services in this repository are deployed on a Google Kubernetes Engine cluster using Nixery.
web/blogandweb/homepagecontain my blog and website setup (serving at tazj.in)web/cgit-tazcontains a slightly patched version ofcgitthat serves my git web interface at git.tazj.inops/journaldrivercontains a small Rust daemon that can forward logs from journald to Stackdriver Logging
Miscellaneous
Presentations I've given in the past are in the presentations folder, these
cover a variety of topics and some of them have links to recordings.
There's a few fun things in the fun/ folder, often with context given in the
README. Check out my list of the best tools for example.
Contributing
If you'd like to contribute to any of the tools in here, please check out the contribution guidelines.