CVE-2026-74470: Linux Vulnerability (CVSS 7.8)

Description

In the Linux kernel, the following vulnerability has been resolved: scsi: scsi_debug: Fix REPORT ZONES alloc_len underflow OOB write resp_report_zones() sizes the reply buffer from the CDB allocation length. The v3 fix rounds alloc_len up with ALIGN() before deriving the descriptor count: rep_max_zones = (ALIGN((u64)alloc_len, RZONES_DESC_HD) - RZONES_DESC_HD) >> ilog2(RZONES_DESC_HD); arr_len = (u64)RZONES_DESC_HD * (rep_max_zones + 1); For alloc_len in 0xFFFFFFC1..0xFFFFFFFF, ALIGN() rounds up to 0x100000000, so arr_len is 4 GB. On 32-bit, kzalloc()'s size_t is 32-bit and truncates 0x100000000 to 0; kzalloc(0) returns ZERO_SIZE_PTR, which passes the !arr check, and desc = arr + 64 is then dereferenced in the loop -> out-of-bounds write / panic. Clamp rep_max_zones to devip->nr_zones. The loop already stops at sdebug_capacity (after nr_zones zones), so a report can never hold more than nr_zones descriptors; the clamp does not change the report, it only bounds arr_len to (nr_zones + 1) * RZONES_DESC_HD, a real device property that can never reach 0x100000000.

Metrics

CVSS 3.1

7.8/10

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

EPSS Probability

0.13%

3.0th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

Vendor	Product	Versions
Linux	Linux	>= ebacb44cb2042b90951140eda806bedad23ef554, < 7b615fc139e35c81077046df44725c532f7e2404; >= 7db0e0c8190a086ef92ce5bb960836cde49540aa, < 5d3e1d006bbb543259f9e31824caadbfff6a5465; >= 7db0e0c8190a086ef92ce5bb960836cde49540aa, < 49e5b25a0b74dbac595f122e5608fdce2918cc4e; >= 7db0e0c8190a086ef92ce5bb960836cde49540aa, < 495058429ca55ab7fcc21977b63b92907ad68066; >= 7db0e0c8190a086ef92ce5bb960836cde49540aa, < 2047ed09bf13453b7d6f9431b112ec07984dd69b; >= 7db0e0c8190a086ef92ce5bb960836cde49540aa, < d6e6da6bc3b53231fac77ffab428da8173ee729c; >= 7db0e0c8190a086ef92ce5bb960836cde49540aa, < 93dde0bf2f39a0f9f57fd610aa3201ce5b753433; c4d2d7c935a4ad20e8e726ca10499cefe4537103; >= 5.15.8, < 5.15.217; >= 5.10.85, < 5.11
Linux	Linux	5.16

References

Timeline

Published: Aug 15, 2026
Last Modified: Aug 23, 2026
Status: Received

Frequently Asked Questions

What is CVE-2026-74470?

In the Linux kernel, the following vulnerability has been resolved: scsi: scsi_debug: Fix REPORT ZONES alloc_len underflow OOB write resp_report_zones() sizes the reply buffer from the CDB allocation length. The v3 fix rounds alloc_len up with ALIGN() before deriving the descriptor count: rep_max_zones = (ALIGN((u64)alloc_len, RZONES_DESC_HD) - RZONES_DESC_HD) >> ilog2(RZONES_DESC_HD); arr_len = (u64)RZONES_DESC_HD * (rep_max_zones + 1); For alloc_len in 0xFFFFFFC1..0xFFFFFFFF, ALIGN() rounds up to 0x100000000, so arr_len is 4 GB. On 32-bit, kzalloc()'s size_t is 32-bit and truncates 0x100000000 to 0; kzalloc(0) returns ZERO_SIZE_PTR, which passes the !arr check, and desc = arr + 64 is then dereferenced in the loop -> out-of-bounds write / panic. Clamp rep_max_zones to devip->nr_zones. The loop already stops at sdebug_capacity (after nr_zones zones), so a report can never hold more than nr_zones descriptors; the clamp does not change the report, it only bounds arr_len to (nr_zones + 1) * RZONES_DESC_HD, a real device property that can never reach 0x100000000.

How severe is CVE-2026-74470?

CVE-2026-74470 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.13% probability of exploitation in the next 30 days.

How do I fix CVE-2026-74470?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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