CVE-2026-89856

High

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).

Package Linux Kernel
Published 2026-09-16
Last modified 2026-09-16
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

8.4

out of 10
High
Attack Vector
Local
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected versions

Linux kernel versions 4.10 and later are affected. Fixed in 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110, 6.18.51, 7.2.5, 7.3-rc1 and their respective stable series.

Affected from
≥ 4.10
Fixed in
✓ 5.10.270 5.10.x ✓ 5.15.221 5.15.x ✓ 6.1.188 6.1.x ✓ 6.6.157 6.6.x ✓ 6.12.110 6.12.x ✓ 6.18.51 6.18.x ✓ 7.2.5 7.2.x ✓ 7.3-rc1

References

8 total
Showing 5 of 8 references View all on NVD

Frequently asked questions

  • What is CVE-2026-89856?

    CVE-2026-89856 is a High severity Linux kernel vulnerability with a CVSS score of 8.4 out of 10 . It affects Linux kernel versions from 4.10 onward and has been patched in 5.10.270, 5.15.221, 6.1.188 and others. CVE-2026-89856 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-89856?

    CVE-2026-89856 has a CVSS score of 8.4 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H .

  • Is there a patch available for CVE-2026-89856?

    Yes. CVE-2026-89856 has been patched. Fixed versions include 5.10.270, 5.15.221, 6.1.188 and others. If you are running Linux kernel 4.10 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-89856 actively exploited?

    No. CVE-2026-89856 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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