Improper Input Validation Affecting kernel-debug-uki-virt package, versions <0:5.14.0-427.13.1.el9_4
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applicationsSnyk Learn
Learn about Improper Input Validation vulnerabilities in an interactive lesson.
Start learning- Snyk IDSNYK-RHEL9-KERNELDEBUGUKIVIRT-8463466
- published5 Dec 2024
- disclosed6 Mar 2024
Introduced: 6 Mar 2024
CVE-2023-52597 (opens in a new tab)How to fix?
Upgrade RHEL:9 kernel-debug-uki-virt to version 0:5.14.0-427.13.1.el9_4 or higher.
This issue was patched in RHSA-2024:2394.
NVD Description
Note: Versions mentioned in the description apply only to the upstream kernel-debug-uki-virt package and not the kernel-debug-uki-virt package as distributed by RHEL.
See How to fix? for RHEL:9 relevant fixed versions and status.
In the Linux kernel, the following vulnerability has been resolved:
KVM: s390: fix setting of fpc register
kvm_arch_vcpu_ioctl_set_fpu() allows to set the floating point control (fpc) register of a guest cpu. The new value is tested for validity by temporarily loading it into the fpc register.
This may lead to corruption of the fpc register of the host process: if an interrupt happens while the value is temporarily loaded into the fpc register, and within interrupt context floating point or vector registers are used, the current fp/vx registers are saved with save_fpu_regs() assuming they belong to user space and will be loaded into fp/vx registers when returning to user space.
test_fp_ctl() restores the original user space / host process fpc register value, however it will be discarded, when returning to user space.
In result the host process will incorrectly continue to run with the value that was supposed to be used for a guest cpu.
Fix this by simply removing the test. There is another test right before the SIE context is entered which will handles invalid values.
This results in a change of behaviour: invalid values will now be accepted instead of that the ioctl fails with -EINVAL. This seems to be acceptable, given that this interface is most likely not used anymore, and this is in addition the same behaviour implemented with the memory mapped interface (replace invalid values with zero) - see sync_regs() in kvm-s390.c.
References
- https://access.redhat.com/security/cve/CVE-2023-52597
- https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html
- https://git.kernel.org/stable/c/0671f42a9c1084db10d68ac347d08dbf6689ecb3
- https://git.kernel.org/stable/c/150a3a3871490e8c454ffbac2e60abeafcecff99
- https://git.kernel.org/stable/c/2823db0010c400e4b2b12d02aa5d0d3ecb15d7c7
- https://git.kernel.org/stable/c/3a04410b0bc7e056e0843ac598825dd359246d18
- https://git.kernel.org/stable/c/5e63c9ae8055109d805aacdaf2a4fe2c3b371ba1
- https://git.kernel.org/stable/c/732a3bea7aba5b15026ea42d14953c3425cc7dc2
- https://git.kernel.org/stable/c/b988b1bb0053c0dcd26187d29ef07566a565cf55
- https://git.kernel.org/stable/c/c87d7d910775a025e230fd6359b60627e392460f