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Fencer Vulns
medium 5.5

CVE-2021-47407 json

KVM: x86: Handle SRCU initialization failure during page track init

published 2024-05-21 2 y ago modified 2026-06-17 4 mo ago also EUVD-2021-34412

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 16%
public exploits
0
none known

Summary

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

KVM: x86: Handle SRCU initialization failure during page track init

Check the return of init_srcu_struct(), which can fail due to OOM, when initializing the page track mechanism. Lack of checking leads to a NULL pointer deref found by a modified syzkaller.

[Move the call towards the beginning of kvm_arch_init_vm. - Paolo]

Patch / fix

  • Linux Linux 5.10.71, 5.14.10, 5.15
  • linux Debian 14, Debian 13, Debian 12 5.14.12-1

debian advisories DEBIAN-CVE-2021-47407

  • kernel-syms SLES for SAP 12 SP5, SLES 12 SP5 4.12.14-122.222.1
  • kernel-source SLES for SAP 12 SP5, SLES 12 SP5 4.12.14-122.222.1
  • kernel-default SLES for SAP 12 SP5, SLES 12 SP5, SLE Workstation Extension 12 SP5 +2 more 4.12.14-122.222.1
  • kernel-obs-build SLE Software Development Kit 12 SP5 4.12.14-122.222.1
  • kernel-rt SLE Real Time 12 SP5 4.12.14-10.191.1
  • kernel-syms-rt SLE Real Time 12 SP5 4.12.14-10.191.1
  • kernel-rt_debug SLE Real Time 12 SP5 4.12.14-10.191.1
  • kernel-source-rt SLE Real Time 12 SP5 4.12.14-10.191.1

suse advisories SUSE-SU-2024:2561-1SUSE-SU-2024:2381-1SUSE-SU-2024:2360-1SUSE-SU-2024:2190-1SUSE-SU-2024:2189-1SUSE-SU-2024:2019-1

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-2021-47407 updated cvss 4.4

kernel: KVM: x86: Handle SRCU initialization failure during page track init

  • Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more
    affected: no fix available
  • 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 9 rv, perf, rtla, kernel, bpftool, libperf, +83 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

0.25% chance of exploitation in the next 30 days, higher than 16% 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:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
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.