CVE-2026-31746: s390/zcrypt: Fix memory leak with CCA cards used as accelerator
In the Linux kernel, the following vulnerability has been resolved:
s390/zcrypt: Fix memory leak with CCA cards used as accelerator
Tests showed that there is a memory leak if CCA cards are used as accelerator for clear key RSA requests (ME and CRT). With the last rework for the memory allocation the AP messages are allocated by apinitapmsg() but for some reason on two places (ME and CRT) the older allocation was still in place. So the first allocation simple was never freed.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-nvidiato a version that resolves this vulnerability.Fixed in 7.0.0-1006.6 - Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 6.19.12-1 - Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 6.1.176-1Fixed in 6.1.190-1Fixed in 6.12.107-1Fixed in 6.12.116-1Fixed in 7.2.15-1Fixed in 7.3.4-1
Event History
Frequently Asked Questions
Which systems are exposed to this issue?
The issue affects Linux kernel systems using s390/zcrypt with CCA cards configured as accelerators for clear-key RSA modular exponentiation (ME) or Chinese Remainder Theorem (CRT) requests.
What conditions are required to trigger the leak?
A clear-key RSA ME or CRT request must be processed through a CCA card used as an accelerator. The leak occurs because an older allocation remained in these two paths after AP message allocation moved to ap_init_apmsg().
What is the operational impact?
Repeated affected requests can leak memory, potentially exhausting available memory and causing a denial of service.