misc: fastrpc: Remove buffer from list prior to unmap operation

published 2026-08-22 2 mo ago modified 2026-10-14 26 d ago also EUVD-2026-64584

cvss: 7.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.1%; EPSS 0.1% chance of exploitation in 30 days, percentile 2%
public exploits: 0; none known

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

fastrpc_req_munmap_impl() is called to unmap any buffer. The buffer is getting removed from the list after it is unmapped from DSP. This can create potential race conditions if multiple threads invoke unmap concurrently, where one thread may remove the entry from the list while another thread's unmap operation is still ongoing.

Fix this by removing the buffer entry from the list before calling the unmap operation. If the unmap fails, the entry is re-added to the list so that userspace can retry the unmap, or alternatively, the buffer will be cleaned up during device release when the DSP process is torn down and all DSP-side mappings are freed along with remaining buffers in the list.

Patch / fix

fixed in 1 distros 3 links 8

Linux Linux 5.10.267, 5.15.218, 6.1.185, 6.6.152, 6.12.104, 6.18.45, 7.1.9, 7.2

debian ubuntu suse

linux Debian 12 6.1.187-1
linux Debian 13 6.12.105-1
linux Debian 14 7.1.9-1
linux-6.12 Debian 12 6.12.107-1~deb12u1

debian advisories DEBIAN-CVE-2026-74647

linux Ubuntu 22.04 LTS 5.15.0-202.212
linux Ubuntu 26.04 LTS 7.0.0-42.42
linux-aws Ubuntu 22.04 LTS 5.15.0-1119.126
linux-aws Ubuntu 26.04 LTS 7.0.0-1016.17
linux-gcp Ubuntu 22.04 LTS 5.15.0-1120.130
linux-gcp Ubuntu 26.04 LTS 7.0.0-1016.18
linux-gke Ubuntu 22.04 LTS 5.15.0-1115.121
linux-ibm Ubuntu 22.04 LTS 5.15.0-1113.117

ubuntu advisories UBUNTU-CVE-2026-74647

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-2026-74647 updated 2026-11-05 cvss 5.5

kernel: misc: fastrpc: Remove buffer from list prior to unmap operation

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 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
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

Exploit prediction

0.13% chance of exploitation in the next 30 days, higher than 2% 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-2026-74647
NVD CVE-2026-74647

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