CVE-2024-41032

A vulnerability was found in the Linux kernel that involves improper handling of per-CPU data in systems where cpu_possible_mask has gaps between CPUs. This can lead to an index which accesses non-existent or unset CPU areas and potentially causes kernel crashes.

A moderate severity vulnerability was found in the Linux kernel's vmalloc memory management subsystem, affecting the Red Hat Enterprise Linux 9 kernel. A per-CPU vmap_block_queue is used as a hash table in the vmalloc code under the incorrect assumption that cpu_possible_mask has no gaps between set CPUs. On systems where such gaps exist, such as SPARC, the addr_to_vb_xa() hash function can return an index that accesses a not-possible and not-set-up CPU area through the per_cpu() macro, resulting in a kernel oops. The consequence is a kernel crash and denial of service (Red Hat CVSS 3.1 score 5.5, AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H); the flaw does not impact confidentiality or integrity. Within the current Red Hat product scope, the kernel and kernel-rt components in the Red Hat Enterprise Linux 9 rhel-9.5 stream are affected and a fix is being pursued through the delegated kernel maintenance workflow, while the RHEL 9.2 and RHEL 9.4 z-streams and the Red Hat Enterprise Linux 8 update streams (including kernel-rt) were assessed as not affected. The Hosted OpenShift (ARO/OSD) clusters are not affected, the Red Hat Enterprise Linux 7 and 6 ELS streams are out of active support scope (OOSS), and Fedora (Community Projects) ships affected kernels. Red Hat's moderate rating differs from the CVE.org rating of 7.8 because the technical evidence supports an availability-only impact from a local kernel crash rather than the high confidentiality and integrity impacts stated in the CVE.org vector.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.