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initrd/bin/kexec-save-default.sh: skip symlinks when finding crypttabfiles#2155

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initrd/bin/kexec-save-default.sh: skip symlinks when finding crypttabfiles#2155
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tlaurion:nixos-initramfs-skip_crypttab_symlink

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@tlaurion tlaurion commented Jul 8, 2026

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  • NixOS initrds contain /etc/crypttab as a symlink to a Nix store path (e.g. /nix/store/-initrd-crypttab). When unpacked into /tmp/initrd_extract, the symlink target is an absolute path that does not exist on the Heads recovery system, making cat fail.
  • find without -type f matched the dangling symlink, causing cat to error out inside a pipefail pipeline, which killed the crypttab parsing loop and caused kexec-save-default.sh to fail.
  • Add -type f to only match regular files, skipping symlinks.

As a result, a crypttab is generated pointing key unsealed and injected TPM DUK through passphrase in additional cpio passed alongside initramfs on kexec call, and that injected cpio successfully decrypt my 2 luks container setup described under #2154

It is to note that unencrypted /boot support option from installer was sadly completely removed in the aftermath of #1348. I am unaware of when /boot got completely removed, which I find sad, requiring manual partitioning. At least, this PR permits TPM DUK on "brainless" partitionning scheme, where iniramfs can decrypt rootfs partitioning with swap, without needing rootfs to be already decrypted. If someone is from/within NixOS and wants to tackle the installer issues, be my guest :)

Fixes #2154

… files

- NixOS initrds contain /etc/crypttab as a symlink to a Nix store path
  (e.g. /nix/store/<hash>-initrd-crypttab). When unpacked into
  /tmp/initrd_extract, the symlink target is an absolute path that does
  not exist on the Heads recovery system, making cat fail.
- find without -type f matched the dangling symlink, causing cat to
  error out inside a pipefail pipeline, which killed the crypttab
  parsing loop and caused kexec-save-default.sh to fail.
- Add -type f to only match regular files, skipping symlinks.

Signed-off-by: Thierry Laurion <insurgo@riseup.net>
Copilot AI review requested due to automatic review settings July 8, 2026 19:22

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Installing from nixos-graphical-26.05.590.ec942ba042da-x86_64-linux.iso can't have TPM DUK setuped

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