File 0005-docs-Document-available-crypto-disks-checks.patch of Package grub2
From 45fffe05e9c33582258a88b4a722a5a561dbfa6e Mon Sep 17 00:00:00 2001
From: Maxim Suhanov <dfirblog@gmail.com>
Date: Thu, 8 May 2025 19:02:11 +0200
Subject: [PATCH 5/8] docs: Document available crypto disks checks
Document the --cryptodisk-only argument. Also, document the
"cryptocheck" command invoked when that argument is processed.
Signed-off-by: Maxim Suhanov <dfirblog@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---
docs/grub.texi | 22 +++++++++++++++++++++-
1 file changed, 21 insertions(+), 1 deletion(-)
diff --git a/docs/grub.texi b/docs/grub.texi
index 9aaea72826..1c078c5c5b 100644
--- a/docs/grub.texi
+++ b/docs/grub.texi
@@ -4368,6 +4368,7 @@ you forget a command, you can run the command @command{help}
* configfile:: Load a configuration file
* cpuid:: Check for CPU features
* crc:: Compute or check CRC32 checksums
+* cryptocheck:: Check if a device is encrypted
* cryptomount:: Mount a crypto device
* cutmem:: Remove memory regions
* date:: Display or set current date and time
@@ -4680,6 +4681,16 @@ Alias for @code{hashsum --hash crc32 arg @dots{}}. See command @command{hashsum}
(@pxref{hashsum}) for full description.
@end deffn
+@node cryptocheck
+@subsection cryptocheck
+
+@deffn Command cryptocheck device
+Check if a given diskfilter device is backed by encrypted devices
+(@pxref{cryptomount} for additional information).
+
+The command examines all backing devices, physical volumes, of a specified
+logical volume, like LVM2, and fails when at least one of them is unencrypted.
+@end deffn
@node cryptomount
@subsection cryptomount
@@ -5531,7 +5542,8 @@ unbootable. @xref{Using GPG-style digital signatures}, for more information.
@deffn Command search @
[@option{--file}|@option{--label}|@option{--fs-uuid}] @
- [@option{--set} [var]] [@option{--no-floppy}|@option{--efidisk-only}] name
+ [@option{--set} [var]] [@option{--no-floppy}|@option{--efidisk-only}|@option{--cryptodisk-only}] @
+ name
Search devices by file (@option{-f}, @option{--file}), filesystem label
(@option{-l}, @option{--label}), or filesystem UUID (@option{-u},
@option{--fs-uuid}).
@@ -5546,6 +5558,14 @@ devices, which can be slow.
The (@option{--efidisk-only}) option prevents searching any other devices then
EFI disks. This is typically used when chainloading to local EFI partition.
+The (@option{--cryptodisk-only}) option prevents searching any devices other
+than encrypted disks. This is typically used when booting from an encrypted
+file system to ensure that no code gets executed from an unencrypted device
+having the same filesystem UUID or label.
+
+This option implicitly invokes the command @command{cryptocheck}, if it is
+available (@pxref{cryptocheck} for additional information).
+
The @samp{search.file}, @samp{search.fs_label}, and @samp{search.fs_uuid}
commands are aliases for @samp{search --file}, @samp{search --label}, and
@samp{search --fs-uuid} respectively.
--
2.49.0