A use-after-free flaw was found in the add_partition in block/partitions/core.c in the Linux kernel.

published 2022-03-23 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-34018

cvss: 5.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 27%
public exploits: 0; none known

A use-after-free flaw was found in the add_partition in block/partitions/core.c in the Linux kernel. A local attacker with user privileges could cause a denial of service on the system. The issue results from the lack of code cleanup when device_add call fails when adding a partition to the disk.

Patch / fix

fixed in 1

linux linux_kernel 5.15

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-2021-4150 updated 2026-11-07 cvss 5.1

kernel: Block subsystem mishandles reference counts

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, +82 more
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

0.34% chance of exploitation in the next 30 days, higher than 27% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

lkml.org https://lkml.org/lkml/2021/10/18/485 referenced PoC, tagged "exploit" by a source, unverified
lkml.org https://lkml.org/lkml/2021/9/6/781 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.1	5.5	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD	2.0	4.9	AV:L/AC:L/Au:N/C:N/I:N/A:C

Affected products

n/a kernel

Classification

Weakness

CWE-416 Use After Free

Technology feeds

Linux kernel rss critical rss

References

lkml.org /lkml/2021/10/18/485
exploit, third-party-advisory
lkml.org /lkml/2021/9/6/781
exploit, third-party-advisory
bugzilla.redhat.com /show_bug.cgi?id=2025938
issue-tracking, third-party-advisory

Sources

CVE List CVE-2021-4150
NVD CVE-2021-4150

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