Bug#1089042: refuses to run hook scripts written in anything but sh

[Andras Korn <korn-debbugs@elan.rulez.org>]

Package: initramfs-tools-core
Version: 0.145
Severity: normal
Tags: patch

Hi,

in /usr/share/initramfs-tools/hook-functions, line 926, you invoke sh -n on hook scripts and skip hook scripts that fail to validate as sh scripts. This makes it effectively impossible to use a hook written in anything other than sh.

However, the section on hook scripts in initramfs-tools(8) doesn't say that scripts have to be valid Bourne shell scripts in order to be run.

I think it would be best to let the user deal with errors in their own hook scripts instead of almost-silently skipping the ones that were written in something other than `sh`.

The next-best thing would be to only invoke `sh -n` on sh scripts; e.g. something like this:

		# skip bad syntax
		if head -n 1 "${si_x}" | grep -Eq '^#!/bin/sh([[:space:]].*?)'; then
			if ! sh -n "${si_x}" ; then
				[ "${verbose}" = "y" ] \
				&& echo "$si_x ignored: bad syntax" >&2
				continue
			fi
		fi

As a last resort, you could amend the documentation to say that all hook scripts *must* be valid Bourne sh scripts; but I think it would be pretty backwards to forbid running "plugins" whose syntax the main script can't validate.

(Re "almost silently": I don't know where the "ignored: bad syntax" message goes, but it doesn't make it to the console. All I had was '/etc/initramfs-tools/hooks/myhook: 50: Syntax error: "(" unexpected'.)

András

-- System Information:
Debian Release: trixie/sid
  APT prefers stable-security
  APT policy: (500, 'stable-security'), (350, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 6.11.10-amd64 (SMP w/8 CPU threads; PREEMPT)
Init: runit (via /run/runit.stopit)

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