#883595 xts module should depend on ecb

Package:
src:linux
Source:
linux
Submitter:
Francis Russell
Date:
2022-05-31 09:00:03 UTC
Severity:
important
#883595#5
Date:
2017-12-05 14:16:42 UTC
From:
To:
Apparently from Linux 4.10 onwards, the ecb module became a dependency
of xts[1]. I am running a custom kernel in which both XTS and ECB are
built as modules (kernel config attached for 4.14.3). However, ECB does
not appear in the initrd, causing the system to be unable to mount the
encrypted root.

It's unclear to me how this dependency should be picked up. The only
mention of ecb in lsmod (output attached for 4.14.3 kernel) is as
follows:

ecb                    16384  2

Attempting to boot a locally built kernel from 4.10 sources onwards
(most recently tried 4.14.3) will fail to be able to mount encrypted
root unless I add ecb to /etc/initramfs-tool/modules. I am using
make-kpkg for all kernel builds.

This issue does not appear to occur with Debian's own kernels, perhaps
because something else is pulling in the ecb dependency when building
the initrd.

[1] https://www.spinics.net/lists/stable/msg160678.html
#883595#10
Date:
2017-12-05 19:58:48 UTC
From:
To:
Control: retitle  -1 xts module should depend on ecb
Control: reassign -1 src:linux 4.10.1-1
Control: affects  -1 cryptsetup

The issue was reported against cryptsetup's upstream BTS earlier this
year: https://gitlab.com/cryptsetup/cryptsetup/issues/319 .

The xts module needs to explicitly depend on ecb.  AFAICT Milan's patch
[0] has been applied to 4.14.0-1-amd64, but modinfo(8) still doesn't
list ecb in its dependencies, so the initramfs hook file doesn't pull it
automatically.

In the meantime, a workaround is to manually add ‘ecb’ to
/etc/initramfs-tools/modules.  Doesn't seem needed on systems with
AES-NI support, though; there I don't have ecb in the initrd, and

    $ grep '^driver\s*:\s*xts' /proc/crypto
    driver       : xts-aes-aesni

while on a system without AES-NI support:

    $ grep '^driver\s*:\s*xts' /proc/crypto
    driver       : xts(ecb(aes-asm))
#883595#25
Date:
2022-05-31 08:55:27 UTC
From:
To:
Version: 4.11-1~exp1

In commit 12cb3a1c4184f891d965d1f39f8cfcc9ef617647 that dependency was added
to the upstream kernel and part of 4.11-rc1 and the first upload to the Debian
archive was with kernel version 4.11-1~exp1, so close it with that version.