Public bug reported:
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
scatter-gather input and output lists correct when list
entries with sizes not multiples of the blocksize of 16
bytes are used. Result may be wrong calculated encrypted
or decrypted data.
This can only happen on z14 (this is the only machine
which supports aes-gcm in hardware via CPACF). Please note
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
exploiters of aes-gcm within the kernel may be affected.
Solution: Rework of the scatter/gather walk within the aes_s390 kernel
module implementation with the goal to support any list
entry size.
Reproduction: With kernel 5.1 there has been an improvement on the crypto
selftests. There are now tests run with fragmented
scatter/gather lists. So:
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
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.
4. Without the fix something 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.
Component: kernel
Upstream-ID: bef9f0ba300a55d79a69aa172156072182176515
This request is targeted for 19.10, but should also be applied to 18.04
and 19.04
** Affects: linux (Ubuntu)
Importance: Undecided
Assignee: Skipper Bug Screeners (skipper-screen-team)
Status: New
** Tags: architecture-s39064 bugnameltc-178123 severity-high
targetmilestone-inin1910
** Tags added: architecture-s39064 bugnameltc-178123 severity-high
targetmilestone-inin1910
** Changed in: ubuntu
Assignee: (unassigned) => Skipper Bug Screeners (skipper-screen-team)
** Package changed: ubuntu => linux (Ubuntu)
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https://bugs.launchpad.net/bugs/1832623
Title:
[UBUNTU] kernel: Fix gcm-aes-s390 wrong scatter-gather list processing
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