This bug is missing log files that will aid in diagnosing the problem.
While running an Ubuntu kernel (not a mainline or third-party kernel)
please enter the following command in a terminal window:
apport-collect 1860231
and then change the status of the bug to 'Confirmed'.
If, due to the nature of the issue you have encountered, you are unable
to run this command, please add a comment stating that fact and change
the bug status to 'Confirmed'.
This change has been made by an automated script, maintained by the
Ubuntu Kernel Team.
** Changed in: linux (Ubuntu)
Status: New => Incomplete
--
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1860231
Title:
5.4.0-11 crash on cryptsetup open
Status in linux package in Ubuntu:
Incomplete
Bug description:
An attempt to run cryptsetup open on a newly created LUKS partition on
Ubuntu Core 20 causes a kernel crash. This happens in 100% of the
attempts on the snapd Core 20 installation test, but on an image
created to reproduce this bug it happens only when certain parameters
are passed to cryptsetup. Both images are built similarly so the
reason for this discrepancy is unknown. The kernel was installed from
pc-kernel_374.snap.
Linux version 5.4.0-11-generic (buildd@lgw01-amd64-021) (gcc version
9.2.1 20200104 (Ubuntu 9.2.1-22ubuntu2)) #14-Ubuntu SMP Thu Jan 9
16:14:26 UTC 2020
Version signature: Ubuntu 5.4.0-11.14-generic 5.4.8
How to reproduce the crash in 3 "easy" steps:
1. Build a Core 20 image using the attached model file:
1.1. Install the ubuntu-image from latest/edge
$ sudo snap install --channel latest/edge ubuntu-image
1.2. Build the image
$ sudo ubuntu-image --image-size=4G ubuntu-core-20-amd64.model
2. Boot the image in kvm
2.1. Install ovmf version 0~20190606.20d2e5a1-2ubuntu1 or newer (the
stock ovmf from bionic may not work)
2.2. Boot the image
$ sudo kvm -snapshot -m 2048 -smp 4 \
-netdev user,id=mynet0,hostfwd=tcp::8022-:22,hostfwd=tcp::8090-:80 \
-device virtio-net-pci,netdev=mynet0 \
-drive file=pc.img,if=virtio \
-bios /usr/share/OVMF/OVMF_CODE.ms.fd
2.3. In the grub menu, edit the default option to include parameter
"systemd.debug-shell=1" in the kernel command line
2.4. Boot the kernel
3. Crash the kernel
3.1. When the system boots to the "Press enter to configure"
message, press ALT-F9 to enter the debug shell.
3.2. The system should have two partitions in /dev/vda. Create a
third one with fdisk.
3.3. Create a LUKS encrypted partition:
# echo 123|cryptsetup luksFormat -q --type luks2 --key-file - --pbkdf
argon2i --iter-time 1 /dev/vda3
(the system will complain about a missing locking directory,
just ignore it.)
3.4. Open the encrypted device:
# echo 123|cryptsetup open --key-file - /dev/vda name
3.5. Read the crash message
The attached screenshots show these steps being executed.
A few notes:
- The backtrace seems very similar to the one reported in bug #1835279,
however that problem was possibly caused by a race between partition creation
and LUKS formatting. This time it doesn't seem to be the case, delays between
commands don't help us here.
- In the test case above using large values of KDF iter-time may prevent the
crash. I successfully opened the device in kernel 5.4.0-9 with --iter-time
larger than 100, but 5.4.0-11 seems to require values closer to 1000.
Regardless of the --iter-time value used, the crash always happen when running
the test in a spread-driven automated environment (same kernel with image built
in the same way, some other variable seems to be disturbing the system).
- All necessary modules are loaded before the LUKS partition creation (i.e.
it doesn't seem to be caused by a race between dm-crypt loading and cryptsetup
luksFormat for example).
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1860231/+subscriptions
--
Mailing list: https://launchpad.net/~kernel-packages
Post to : [email protected]
Unsubscribe : https://launchpad.net/~kernel-packages
More help : https://help.launchpad.net/ListHelp
