CVE-2026-90173

A flaw was found in the Linux kernel's SMB Direct (smbdirect) component. This vulnerability occurs because the system attempts to access memory that has already been freed when handling network communication. A remote attacker could exploit this timing issue, potentially leading to system instability or a denial of service (DoS).

A use after free can occur in the SMB Direct teardown path because completion queues created with workqueue based polling are freed while ib_cq_poll_work can still be pending or requeued. A late RDMA completion after rdma_destroy_qp can schedule work against the freed CQ, leading to an invalid kernel memory access and a kernel crash. The KASAN trace confirms a slab use after free in ib_cq_poll_work followed by a fault in rxe_req_notify_cq. For the CVSS the PR:N value is used because a remote SMB Direct peer may influence connection teardown and late completion processing without local privileges on the target. AV:A and AC:H are used because the attacker normally needs access to the same RDMA or Soft RoCE network and must trigger a timing dependent race involving a late provider completion. The demonstrated impact is denial of service.

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.