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Fencer Vulns
medium 5.5

CVE-2021-46923 json

fs/mount_setattr: always cleanup mount_kattr

published 2024-02-27 2 y ago modified 2026-06-17 4 mo ago also EUVD-2021-33571

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 11%
public exploits
0
none known

Summary

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

fs/mount_setattr: always cleanup mount_kattr

Make sure that finish_mount_kattr() is called after mount_kattr was succesfully built in both the success and failure case to prevent leaking any references we took when we built it. We returned early if path lookup failed thereby risking to leak an additional reference we took when building mount_kattr when an idmapped mount was requested.

Patch / fix

  • Linux Linux 5.15.13, 5.16
  • linux Debian 14, Debian 13, Debian 12 5.15.15-1

debian advisories DEBIAN-CVE-2021-46923

  • kernel-rt SLE Micro 5.4, SLE Micro 5.3, openSUSE Leap Micro 5.4 +1 more 5.14.21-150400.15.71.1
  • kernel-source-rt SLE Micro 5.4, SLE Micro 5.3 5.14.21-150400.15.71.1
  • kernel-rt SLE Micro 5.5, Real Time Module 15 SP5, openSUSE Leap 15.5 5.14.21-150500.13.38.1
  • kernel-syms-rt Real Time Module 15 SP5, openSUSE Leap 15.5 5.14.21-150500.13.38.1
  • kernel-rt_debug Real Time Module 15 SP5, openSUSE Leap 15.5 5.14.21-150500.13.38.1
  • kernel-source-rt SLE Micro 5.5, Real Time Module 15 SP5, openSUSE Leap 15.5 5.14.21-150500.13.38.1
  • kernel-syms SLE High Performance Computing 15 SP4-ESPOS, Manager Server 4.3, Manager Proxy 4.3 +3 more 5.14.21-150400.24.111.1
  • kernel-source SLE High Performance Computing 15 SP4-ESPOS, Manager Server 4.3, Manager Proxy 4.3 +3 more 5.14.21-150400.24.111.1

suse advisories SUSE-SU-2024:0977-1SUSE-SU-2024:0910-1SUSE-SU-2024:0900-2SUSE-SU-2024:0900-1SUSE-SU-2024:0858-1SUSE-SU-2024:0855-1

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-2021-46923 updated cvss 5.5

kernel: fs/mount_setattr: always cleanup mount_kattr

  • 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
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-selftests-internal
    affected: no fix available
  • 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

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.21% chance of exploitation in the next 30 days, higher than 11% of all scored CVEs (FIRST EPSS, 2026-11-08).

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:H/I:N/A:N

Affected products

  • Linux Linux

Classification

Weakness
  • CWE-668 Exposure of Resource to Wrong Sphere
Technology feeds

References

Sources

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.