crypto: ccp - Fix snp_filter_reserved_mem_regions() off-by-one

published 2026-08-15 2 mo ago modified 2026-10-16 23 d ago also EUVD-2026-59551

cvss: 7.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 8%
public exploits: 0; none known

In the Linux kernel, the following vulnerability has been resolved:

Sashiko notes:

> regarding the bounds check in snp_filter_reserved_mem_regions() > called via walk_iomem_res_desc(): does the check > if ((range_list->num_elements * 16 + 8) > PAGE_SIZE) > allow an off-by-one heap buffer overflow? > > If range_list->num_elements is 255, 255 * 16 + 8 = 4088, which is <= 4096. > Writing range->base (8 bytes) fills 4088-4095, but writing range->page_count > (4 bytes) would write to 4096-4099, overflowing the kzalloc-allocated > PAGE_SIZE buffer.

Fix this by accounting for the entry about to be written to, in addition to the entries that are already allocated.

Patch / fix

fixed in 1 distros 3 links 4

Linux Linux 6.12.97, 6.18.40, 7.1.5, 7.2

debian ubuntu suse

linux Debian 13 6.12.100-1
linux Debian 14 7.1.5-1

debian advisories DEBIAN-CVE-2026-74404

linux Ubuntu 26.04 LTS 7.0.0-38.38
linux-aws Ubuntu 26.04 LTS 7.0.0-1014.14
linux-gcp Ubuntu 26.04 LTS 7.0.0-1014.14
linux-gke Ubuntu 26.04 LTS 7.0.0-1008.9
linux-ibm Ubuntu 26.04 LTS 7.0.0-1015.15
linux-azure Ubuntu 26.04 LTS 7.0.0-1017.17
linux-riscv Ubuntu 26.04 LTS 7.0.0-38.38.1
linux-oracle Ubuntu 26.04 LTS 7.0.0-1013.13

ubuntu advisories UBUNTU-CVE-2026-74404

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

kernel-source Linux Micro 6.0 6.4.0-159998.55.1
kernel-default Linux Micro 6.0 6.4.0-159998.55.1
kernel-kvmsmall Linux Micro 6.0 6.4.0-159998.55.1
kernel-default-base Linux Micro 6.0 6.4.0-159998.55.1.159998.21.42
kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.90.1
kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.90.1
kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.53.90.1
kernel-source SLE Module for Development Tools 15 SP7, SLE Module for Basesystem 15 SP7 6.4.0-150700.53.90.1

suse advisories SUSE-SU-2026:24550-1 SUSE-SU-2026:5091-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-74404 updated 2026-11-06 cvss 6.7

kernel: crypto: ccp - Fix snp_filter_reserved_mem_regions() off-by-one

Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +82 more Red Hat Enterprise Linux 10 kernel
affected: workaround, no fix available “Fix deferred”
Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-selftests-internal
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 23 d ago (2026-10-16)

Exploit prediction

0.19% chance of exploitation in the next 30 days, higher than 8% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.8	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

Linux Linux

Classification

Technology feeds

Linux kernel rss critical rss

References

Sources

CVE List CVE-2026-74404
NVD CVE-2026-74404

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary