[UBUNTU] kernel: Fix gcm-aes-s390 wrong scatter-gather list processing
| Affects | Status | Importance | Assigned to | Milestone | |
|---|---|---|---|---|---|
| Ubuntu on IBM z Systems |
Fix Released
|
High
|
Canonical Kernel Team | ||
| linux (Ubuntu) |
Fix Released
|
Undecided
|
Skipper Bug Screeners | ||
| Bionic |
Fix Released
|
Medium
|
Unassigned | ||
| Cosmic |
Invalid
|
Medium
|
Unassigned | ||
| Disco |
Fix Released
|
Medium
|
Unassigned | ||
Bug Description
SRU Justification:
==================
[Impact]
* Wrong encryption/
* gcm-aes-s390 does not process scatter-gather input and output lists correctly if list entries of sizes being not multiples of the blocksize (16 bytes) are used, which results in wrong calculations.
[Fix]
* bef9f0ba300a55d
[Test Case]
* z14 with kernel >= 5.1 needed
* If disabled, enable the crypto self tests.
* Monitor syslog during modprobe of the aes_s390 kernel module. As this module usually gets automatically inserted during system startup you may need to unload the aes_s390 kernel module before re-inserting it.
* Without the fix a message like "kernel: alg: aead: gcm-aes-s390 encryption test failed (wrong result) on test vector 1,..." will show up.
* With the fix, all selftests will pass and nothing is reported in syslog.
[Regression Potential]
* The regression potential can be considered as low since this is purely s390x specific
* affects one mode of the hardware crypto facility CPACF
* and happens only on z14 (since z14 is the only model that currently supports the gcm-aes-s390 mode).
* Applications using aes-gcm via the AF_ALG interface are not affected since this API ensures scatter/gather list entries with chunk sizes in multiples of 16 bytes.
* Changes are limited to a single s390x crypto file /arch/s390/
[Other Info]
* Problem was found during tests at IBM and is a so called 'preventive fix'
* Since this affects z14 only, final test need to be done by IBM.
* Applied cleanly for me on bionic master-next.
__________
Description: kernel: Fix gcm-aes-s390 wrong scatter-gather list processing
Symptom: gcm-aes-s390 wrong en/decryption processing
Problem: The current gcm aes s390 implementation does not process
or decrypted data.
This can only happen on z14 (this is the only machine
that applications using aes-gcm via the AF_ALG interface are
not affected as this API ensures scatter/gather list entries
with chunk sizes in multiples of 16 bytes. However, all
Solution: Rework of the scatter/gather walk within the aes_s390 kernel
Reproduction: With kernel 5.1 there has been an improvement on the crypto
1. You need at least a z14 and kernel >= 5.1.
2. If disabled, enable the crypto self tests.
3. Watch for syslog entries during modprobe of the aes_s390
4. Without the fix something like
Component: kernel
Upstream-ID: bef9f0ba300a55d
This request is targeted for 19.10, but should also be applied to 18.04 and 19.04
CVE References
| tags: | added: architecture-s39064 bugnameltc-178123 severity-high targetmilestone-inin1910 |
| Changed in ubuntu: | |
| assignee: | nobody → Skipper Bug Screeners (skipper-screen-team) |
| affects: | ubuntu → linux (Ubuntu) |
| Changed in ubuntu-z-systems: | |
| assignee: | nobody → Canonical Kernel Team (canonical-kernel-team) |
| importance: | Undecided → High |
| Frank Heimes (fheimes) wrote | #1 |
| Changed in ubuntu-z-systems: | |
| status: | New → Triaged |
| description: | updated |
| Frank Heimes (fheimes) wrote | #2 |
| Changed in linux (Ubuntu): | |
| status: | New → In Progress |
| Changed in ubuntu-z-systems: | |
| status: | Triaged → In Progress |
| Changed in linux (Ubuntu Bionic): | |
| importance: | Undecided → Medium |
| Changed in linux (Ubuntu Cosmic): | |
| importance: | Undecided → Medium |
| Changed in linux (Ubuntu Disco): | |
| importance: | Undecided → Medium |
| Changed in linux (Ubuntu Bionic): | |
| status: | New → Fix Committed |
| Changed in linux (Ubuntu Cosmic): | |
| status: | New → Fix Committed |
| Changed in linux (Ubuntu Disco): | |
| status: | New → Fix Committed |
| Changed in ubuntu-z-systems: | |
| status: | In Progress → Fix Committed |
| Ubuntu Kernel Bot (ubuntu-kernel-bot) wrote | #3 |
| tags: | added: verification-needed-disco |
| bugproxy (bugproxy) wrote Comment bridged from LTC Bugzilla | #4 |
| Ubuntu Kernel Bot (ubuntu-kernel-bot) wrote | #5 |
| tags: | added: verification-needed-cosmic |
| tags: | added: verification-needed-bionic |
| Ubuntu Kernel Bot (ubuntu-kernel-bot) wrote | #6 |
| Frank Heimes (fheimes) wrote | #7 |
| tags: |
added: verification-done-bionic verification-done-cosmic verification-done-disco removed: verification-needed-bionic verification-needed-cosmic verification-needed-disco |
| Launchpad Janitor (janitor) wrote | #8 |
| Changed in linux (Ubuntu Bionic): | |
| status: | Fix Committed → Fix Released |
| Frank Heimes (fheimes) wrote | #9 |
| Changed in linux (Ubuntu): | |
| status: | In Progress → Fix Released |
| Launchpad Janitor (janitor) wrote | #10 |
| Changed in linux (Ubuntu Disco): | |
| status: | Fix Committed → Fix Released |
| Frank Heimes (fheimes) wrote | #11 |
| Changed in linux (Ubuntu Cosmic): | |
| status: | Fix Committed → Invalid |
| Changed in ubuntu-z-systems: | |
| status: | Fix Committed → Fix Released |
| bugproxy (bugproxy) wrote | #12 |
| Ubuntu Kernel Bot (ubuntu-kernel-bot) wrote | #13 |
| tags: | added: verification-needed-xenial |
Commit ID got upstream accepted with kernel v5.2-rc3, so will be automatically part of 19.10, when target kernel 5.2 finally lands in eoan.
Kernel SRU needed for 19.04 and 18.04.