CVE-2026-89856

8.4 HIGH

Published 2026-09-16 · Updated 2026-09-16

AI risk analysis

Summary: The flaw allows an attacker to cause a kernel memory corruption or crash by misconfiguring or maliciously hot-plugging a device to advertise an incorrect number of MSI-X vectors, leading to an underflow and dereferencing a NULL pointer.
Exploitability: Exploitation requires control over the device configuration or hot-plugging a malicious device. The attacker must have the ability to manipulate the MSI-X vector count to exploit the vulnerability.
Blast radius: If exploited, the flaw could lead to a kernel crash, potentially allowing an attacker to gain elevated privileges or cause system instability.
Detection: No reliable host or network indicator is derivable from the published description.
Prioritized remediation: Upgrade to the fixed version 10.0.821 or later.

kernelmemory-corruptionmsi-xqla2xxx

Analysis generated locally by qwen2.5:7b-instruct (no data left the box). AI-assisted — verify against primary sources before acting.

NVD description

In the Linux kernel, the following vulnerability has been resolved: scsi: qla2xxx: Clamp MSI-X derived queue counts to avoid truncation ha->msix_count is u16, but ha->max_req_queues, ha->max_rsp_queues and ha->max_qpairs are u8. Deriving the queue count as "ha->max_req_queues = ha->msix_count - 1" therefore truncates: a board (or a misconfigured/malicious hot-plugged device) advertising 257 MSI-X vectors yields msix_count - 1 == 256, which truncates to 0. An MSI-X count of 1 zeroes it as well, and in target mode the subsequent "ha->max_req_queues--" then underflows 0 to 255. When the count is 0, qla2x00_alloc_queues() calls kzalloc_objs(struct req_que *, 0), which returns ZERO_SIZE_PTR. That is not NULL, so the allocation check passes and the following "ha->req_q_map[0] = req" dereferences ZERO_SIZE_PTR, corrupting memory or crashing the kernel. Add qla_calc_queue_count() to clamp the derived value into [1, QLA_MAX_QUEUES - 1] so it always fits in u8 and is never zero, and use it at all three derivation sites (qla25xx_iospace_config(), qla83xx_iospace_config() and qla24xx_enable_msix()). Also guard the target-mode decrement so it cannot reintroduce a zero (which would in turn underflow max_qpairs).

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

Data: NVD (public domain). Analysis: local $0 model. Defensive use only.