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Fencer Intel
low 3.3

CVE-2021-46934 json

i2c: validate user data in compat ioctl

published 2y ago modified 4mo ago also EUVD-2021-33582

cvss
3.3
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:

i2c: validate user data in compat ioctl

Wrong user data may cause warning in i2c_transfer(), ex: zero msgs. Userspace should not be able to trigger warnings, so this patch adds validation checks for user data in compact ioctl to prevent reported warnings

Patch / fix

  • Linux Linux 4.19.224, 5.4.170, 5.10.90, 5.15.13, 5.16
  • linux Debian 14, Debian 13, Debian 12 5.15.15-1

debian advisories DEBIAN-CVE-2021-46934

  • linux Ubuntu 18.04 LTS 4.15.0-173.182
  • linux Ubuntu 20.04 LTS 5.4.0-105.119
  • linux-aws Ubuntu 18.04 LTS 4.15.0-1124.133
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1069.73
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1068.72
  • linux-ibm Ubuntu 20.04 LTS 5.4.0-1018.20
  • linux-kvm Ubuntu 18.04 LTS 4.15.0-1110.113
  • linux-kvm Ubuntu 20.04 LTS 5.4.0-1059.62

ubuntu advisories UBUNTU-CVE-2021-46934

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-rt RHEL 8 4.18.0-553.5.1.rt7.346.el8_10
  • kernel-rt-kvm RHEL 8 4.18.0-553.5.1.rt7.346.el8_10
  • kernel-rt-core RHEL 8 4.18.0-553.5.1.rt7.346.el8_10
  • kernel-rt-modules RHEL 8 4.18.0-553.5.1.rt7.346.el8_10
  • kernel-rt-debug-kvm RHEL 8 4.18.0-553.5.1.rt7.346.el8_10
  • kernel-rt-debug-core RHEL 8 4.18.0-553.5.1.rt7.346.el8_10
  • kernel-rt-debug-modules RHEL 8 4.18.0-553.5.1.rt7.346.el8_10
  • kernel-rt-modules-extra RHEL 8 4.18.0-553.5.1.rt7.346.el8_10

red hat advisories RHSA-2024:3627RHSA-2024:3618

  • dtb-aarch64 openSUSE Leap 15.5 5.14.21-150500.55.59.1
  • kernel-64kb SLE Module for Basesystem 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.59.1
  • kernel-syms SLE Module for Development Tools 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.59.1
  • kernel-obs-qa openSUSE Leap 15.5 5.14.21-150500.55.59.1
  • kernel-source SLE Module for Development Tools 15 SP5, SLE Module for Basesystem 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.59.1
  • kernel-default SLE Workstation Extension 15 SP5, SLE Module for Legacy 15 SP5, SLE Module for Basesystem 15 SP5 +4 more 5.14.21-150500.55.59.1
  • kernel-kvmsmall openSUSE Leap 15.5 5.14.21-150500.55.59.1
  • kernel-zfcpdump SLE Module for Basesystem 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.59.1

suse advisories SUSE-SU-2024:1480-1SUSE-SU-2024:1466-1SUSE-SU-2024:0977-1SUSE-SU-2024:0926-1SUSE-SU-2024:0900-2SUSE-SU-2024:0900-1

  • kernel AlmaLinux 8 4.18.0-553.5.1.el8_10
  • perf AlmaLinux 8 4.18.0-553.5.1.el8_10
  • bpftool AlmaLinux 8 4.18.0-553.5.1.el8_10
  • kernel-core AlmaLinux 8 4.18.0-553.5.1.el8_10
  • kernel-tools AlmaLinux 8 4.18.0-553.5.1.el8_10
  • python3-perf AlmaLinux 8 4.18.0-553.5.1.el8_10
  • kernel-modules AlmaLinux 8 4.18.0-553.5.1.el8_10
  • kernel-zfcpdump AlmaLinux 8 4.18.0-553.5.1.el8_10

almalinux advisories ALSA-2024:3618ALSA-2024:3627

  • kernel-rt Rocky Linux 8 4.18.0-553.5.1.rt7.346.el8_10
  • kernel Rocky Linux 8 4.18.0-553.5.1.el8_10

rocky linux advisories RLSA-2024:3627RLSA-2024:3618

Is CVE-2021-46934 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

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-2021-46934 updated cvss 4.4

kernel: i2c: validate user data in compat ioctl

  • 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 rv, perf, rtla, kernel, bpftool, libperf, +82 more
    affected: no fix available
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.5.1.el8_10, kernel 4.18.0-553.5.1.el8_10, bpftool 4.18.0-553.5.1.el8_10, kernel-core 4.18.0-553.5.1.el8_10, kernel-tools 4.18.0-553.5.1.el8_10, python3-perf 4.18.0-553.5.1.el8_10, +15 more Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.5.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.5.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.5.1.el8_10
    fixed: vendor fix RHSA-2024:3618
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.5.1.rt7.346.el8_10, kernel-rt-kvm 4.18.0-553.5.1.rt7.346.el8_10, kernel-rt-core 4.18.0-553.5.1.rt7.346.el8_10, kernel-rt-modules 4.18.0-553.5.1.rt7.346.el8_10, kernel-rt-debug-kvm 4.18.0-553.5.1.rt7.346.el8_10, kernel-rt-debug-core 4.18.0-553.5.1.rt7.346.el8_10, +4 more Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.5.1.rt7.346.el8_10, kernel-rt-core 4.18.0-553.5.1.rt7.346.el8_10, kernel-rt-modules 4.18.0-553.5.1.rt7.346.el8_10, kernel-rt-debug-core 4.18.0-553.5.1.rt7.346.el8_10, kernel-rt-debug-modules 4.18.0-553.5.1.rt7.346.el8_10, kernel-rt-modules-extra 4.18.0-553.5.1.rt7.346.el8_10, +2 more
    fixed: vendor fix RHSA-2024:3627

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
2y ago

Exploit prediction

0.23% chance of exploitation in the next 30 days, higher than 14% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 3.3 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Affected products

  • Linux Linux

Classification

Weakness
  • CWE-754 Improper Check for Unusual or Exceptional Conditions
Technology feeds

References

Sources

Fencer Intel 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.