CVE-2023-54292

A race condition was identified in the RDMA/irdma subsystem of the Linux kernel affecting how completion queue pair (CQP) requests are processed. The cqp_request->request_done memory location is accessed without appropriate synchronization in the irdma_handle_cqp_op function while it is concurrently updated in irdma_cqp_ce_handler. Kernel Concurrency Sanitizer can detect this unsafe access pattern, which may lead to unpredictable behavior, kernel warnings, or system instability

A MODERATE impact data race was found in the Linux kernel RDMA/irdma driver in Red Hat Enterprise Linux 8 and Red Hat Enterprise Linux 9 (kernel and kernel-rt packages). The cqp_request->request_done flag is read without synchronization in irdma_handle_cqp_op() while it is concurrently updated by the CQP completion event handler irdma_cqp_ce_handler() running on another CPU; the race was detected by the Kernel Concurrency Sanitizer (KCSAN). The worst consequence is unpredictable driver behavior, kernel warnings, or system instability, i.e. an availability-only impact (Red Hat CVSS 6.5, CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). Red Hat Enterprise Linux 6, 7, and 10, and Red Hat In-Vehicle OS are not affected because the vulnerable code is not present in those streams. For the affected Red Hat Enterprise Linux 8 and 9 kernel and kernel-rt packages the fix is currently deferred: this is a concurrency correctness defect with availability-only impact, and the corrective change, annotating the shared lockless access with READ_ONCE/WRITE_ONCE, will be delivered in a future kernel update rather than as an immediate z-stream fix. The residual risk of deferring the fix is limited to potential kernel warnings or instability on systems using irdma RDMA hardware. The CVE.org record assigns this flaw a CRITICAL severity (CVSS 9.8), which differs significantly from Red Hat's MODERATE rating; the upstream score does not reflect the technical reality of this race condition, whose impact is confined to availability with no confidentiality or integrity impact.

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 don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.