dm-crypt patch in Linux 4.20.6 Commit e4efd3184d9a63a7923e5c62fa236254f03c6bf8

[23pieces]

Hello everyone!

It seems since kernelversion 4.20.6 many people have problems mounting their encrypted rootfs while booting.

Trying to investigate i found this commit in 4.20.6:
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/drivers/md/dm-crypt.c?id=e4efd3184d9a63a7923e5c62fa236254f03c6bf8

To clarify this issue also persists in 4.20.7 and isn't occuring in 4.20.5.

People having the problem often have something like the following config on their rootfs (including myself):
cryptsetup -v --type luks --cipher aes-xts-plain64 --key-size 512 --hash sha512 --iter-time 5000 --use-random --verify-passphrase luksFormat device

I was trying to investigate the code in the commit and playing around with the dmsetup commands mentioned.

Now on a running system with kernel 4.20.6 i get:

dmsetup create test --table "0 8 crypt aes-cbc-essiv:sha3-256 9c1185a5c5e9fc54612808977ee8f5b9e 0 /dev/sdc 0"      Works

dmsetup create test --table "0 8 crypt aes-cbc-essiv:sha512 9c1185a5c5e9fc54612808977ee8f5b9e 0 /dev/sdc 0"
device-mapper: reload ioctl on test  failed: Invalid argument
Command failed.

dmsetup create test --table "0 8 crypt aes-xts-plain-64:sha3-256 9c1185a5c5e9fc54612808977ee8f5b9e 0 /dev/sdc 0"
device-mapper: reload ioctl on test  failed: Invalid argument
Command failed.

dmsetup create test --table "0 8 crypt aes-xts-plain-64:sha512 9c1185a5c5e9fc54612808977ee8f5b9e 0 /dev/sdc 0"
device-mapper: reload ioctl on test  failed: Invalid argument
Command failed.


At boot people have the following error:
device-mapper: reload ioctl on  failed: Invalid argument
Failed to setup dm-crypt key mapping for device /dev/disk/by-uuid/UUID
Check that kernel supports aes-xts-plain-64 cipher (check syslog for more info)

I don't have a patch for this yet, just wanted to inform you.

Best regards
23pieces

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