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Fencer Vulns
medium 5.5

CVE-2021-47202 json

thermal: Fix NULL pointer dereferences in of_thermal_ functions

published 2024-04-10 2 y ago modified 2026-06-17 4 mo ago also EUVD-2021-33850

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 14%
public exploits
0
none known

Summary

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

thermal: Fix NULL pointer dereferences in of_thermal_ functions

of_parse_thermal_zones() parses the thermal-zones node and registers a thermal_zone device for each subnode. However, if a thermal zone is consuming a thermal sensor and that thermal sensor device hasn't probed yet, an attempt to set trip_point_*_temp for that thermal zone device can cause a NULL pointer dereference. Fix it.

console:/sys/class/thermal/thermal_zone87 # echo 120000 > trip_point_0_temp ... Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020 ... Call trace: of_thermal_set_trip_temp+0x40/0xc4 trip_point_temp_store+0xc0/0x1dc dev_attr_store+0x38/0x88 sysfs_kf_write+0x64/0xc0 kernfs_fop_write_iter+0x108/0x1d0 vfs_write+0x2f4/0x368 ksys_write+0x7c/0xec __arm64_sys_write+0x20/0x30 el0_svc_common.llvm.7279915941325364641+0xbc/0x1bc do_el0_svc+0x28/0xa0 el0_svc+0x14/0x24 el0_sync_handler+0x88/0xec el0_sync+0x1c0/0x200

While at it, fix the possible NULL pointer dereference in other functions as well: of_thermal_get_temp(), of_thermal_set_emul_temp(), of_thermal_get_trend().

Patch / fix

  • Linux Linux 5.4.210, 5.10.81, 5.14.21, 5.15.4, 5.16
  • linux Debian 14, Debian 13, Debian 12 5.15.5-1

debian advisories DEBIAN-CVE-2021-47202

  • linux Ubuntu 20.04 LTS 5.4.0-128.144
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1086.93
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1090.98
  • linux-ibm Ubuntu 20.04 LTS 5.4.0-1034.38
  • linux-iot Ubuntu 20.04 LTS 5.4.0-1005.7
  • linux-kvm Ubuntu 20.04 LTS 5.4.0-1076.81
  • linux-azure Ubuntu 20.04 LTS 5.4.0-1094.100
  • linux-gkeop Ubuntu 20.04 LTS 5.4.0-1054.57

ubuntu advisories UBUNTU-CVE-2021-47202

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-64kb SLE High Performance Computing 15 SP5-ESPOS, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS 5.14.21-150500.55.91.1
  • kernel-syms SLE High Performance Computing 15 SP5-ESPOS, SLES for SAP 15 SP5, SLES 15 SP5-LTSS +1 more 5.14.21-150500.55.91.1
  • kernel-source SLE High Performance Computing 15 SP5-ESPOS, SLES for SAP 15 SP5, SLES 15 SP5-LTSS +1 more 5.14.21-150500.55.91.1
  • kernel-default SLE Micro 5.5, SLE High Performance Computing 15 SP5-ESPOS, SLES for SAP 15 SP5 +3 more 5.14.21-150500.55.91.1
  • kernel-obs-build SLE High Performance Computing 15 SP5-ESPOS, SLES for SAP 15 SP5, SLES 15 SP5-LTSS +1 more 5.14.21-150500.55.91.1
  • kernel-default-base SLE Micro 5.5, SLE High Performance Computing 15 SP5-ESPOS, SLES for SAP 15 SP5 +2 more 5.14.21-150500.55.91.1.150500.6.41.1
  • kernel-rt SLE Micro 5.4, SLE Micro 5.3 5.14.21-150400.15.106.1
  • kernel-source-rt SLE Micro 5.4, SLE Micro 5.3 5.14.21-150400.15.106.1

suse advisories SUSE-SU-2025:0201-1SUSE-SU-2025:0201-2SUSE-SU-2025:0231-1SUSE-SU-2025:0229-1SUSE-SU-2025:0203-1SUSE-SU-2024:1870-1

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-2021-47202 updated cvss 4.4

kernel: thermal: Fix NULL pointer dereferences in of_thermal_ functions

  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 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 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 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

0.24% chance of exploitation in the next 30 days, higher than 14% 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.