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Fencer Vulns
high 7.8

CVE-2021-47311 json

net: qcom/emac: fix UAF in emac_remove

published 2024-05-21 2 y ago modified 2026-06-17 4 mo ago also EUVD-2021-34316

cvss
7.8
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:

net: qcom/emac: fix UAF in emac_remove

adpt is netdev private data and it cannot be used after free_netdev() call. Using adpt after free_netdev() can cause UAF bug. Fix it by moving free_netdev() at the end of the function.

Patch / fix

  • Linux Linux 4.9.277, 4.14.241, 4.19.199, 5.4.135, 5.10.53, 5.13.5, 5.14
  • linux Debian 14, Debian 13, Debian 12 5.14.6-1

debian advisories DEBIAN-CVE-2021-47311

  • linux Ubuntu 18.04 LTS 4.15.0-159.167
  • linux Ubuntu 20.04 LTS 5.4.0-88.99
  • linux-aws Ubuntu 18.04 LTS 4.15.0-1112.119
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1057.60
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1053.57
  • linux-ibm Ubuntu 20.04 LTS 5.4.0-1005.6
  • linux-kvm Ubuntu 18.04 LTS 4.15.0-1100.102
  • linux-kvm Ubuntu 20.04 LTS 5.4.0-1047.49

ubuntu advisories UBUNTU-CVE-2021-47311

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 RHEL 8 4.18.0-553.8.1.el8_10
  • perf RHEL 8 4.18.0-553.8.1.el8_10
  • bpftool RHEL 8 4.18.0-553.8.1.el8_10
  • kernel-core RHEL 8 4.18.0-553.8.1.el8_10
  • kernel-tools RHEL 8 4.18.0-553.8.1.el8_10
  • python3-perf RHEL 8 4.18.0-553.8.1.el8_10
  • kernel-modules RHEL 8 4.18.0-553.8.1.el8_10
  • kernel-zfcpdump RHEL 8 4.18.0-553.8.1.el8_10

red hat advisories RHSA-2024:5281RHSA-2024:4211RHSA-2024:4740RHSA-2024:4352

  • kernel-rt SLE Micro 5.2, SLE Micro 5.1 5.3.18-150300.175.1
  • kernel-source-rt SLE Micro 5.2, SLE Micro 5.1 5.3.18-150300.175.1
  • kernel-default SLES for SAP 15 SP2, SLES 15 SP2-LTSS, SLE Live Patching 15 SP2 +2 more 5.3.18-150200.24.197.1
  • kernel-64kb SLES 15 SP3-LTSS, SLE High Performance Computing 15 SP3-LTSS, Enterprise Storage 7.1 5.3.18-150300.59.167.1
  • kernel-syms SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE High Performance Computing 15 SP3-LTSS +1 more 5.3.18-150300.59.167.1
  • kernel-source SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE High Performance Computing 15 SP3-LTSS +1 more 5.3.18-150300.59.167.1
  • kernel-default SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE Micro 5.2 +5 more 5.3.18-150300.59.167.1
  • kernel-preempt SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE High Performance Computing 15 SP3-LTSS +1 more 5.3.18-150300.59.167.1

suse advisories SUSE-SU-2024:2384-1SUSE-SU-2024:2365-1SUSE-SU-2024:2362-1SUSE-SU-2024:2184-1SUSE-SU-2024:1983-1SUSE-SU-2024:1979-1

  • kernel-rt AlmaLinux 8 4.18.0-553.8.1.rt7.349.el8_10
  • kernel-rt-kvm AlmaLinux 8 4.18.0-553.8.1.rt7.349.el8_10
  • kernel-rt-core AlmaLinux 8 4.18.0-553.8.1.rt7.349.el8_10
  • kernel-rt-modules AlmaLinux 8 4.18.0-553.8.1.rt7.349.el8_10
  • kernel-rt-debug-kvm AlmaLinux 8 4.18.0-553.8.1.rt7.349.el8_10
  • kernel-rt-debug-core AlmaLinux 8 4.18.0-553.8.1.rt7.349.el8_10
  • kernel-rt-debug-modules AlmaLinux 8 4.18.0-553.8.1.rt7.349.el8_10
  • kernel-rt-modules-extra AlmaLinux 8 4.18.0-553.8.1.rt7.349.el8_10

almalinux advisories ALSA-2024:4352ALSA-2024:4211

  • kernel-rt Rocky Linux 8 4.18.0-553.8.1.rt7.349.el8_10
  • kernel Rocky Linux 8 4.18.0-553.8.1.el8_10

rocky linux advisories RLSA-2024:4352RLSA-2024:4211

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-2021-47311 updated cvss 5.5

kernel: net: qcom/emac: fix UAF in emac_remove

  • Red Hat CodeReady Linux Builder EUS (v.8.8) kernel-debuginfo-common-x86_64 4.18.0-477.64.1.el8_8, kernel-debuginfo-common-aarch64 4.18.0-477.64.1.el8_8, kernel-debuginfo-common-ppc64le 4.18.0-477.64.1.el8_8
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2024:4740
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.8.1.el8_10, kernel 4.18.0-553.8.1.el8_10, bpftool 4.18.0-553.8.1.el8_10, kernel-core 4.18.0-553.8.1.el8_10, kernel-tools 4.18.0-553.8.1.el8_10, python3-perf 4.18.0-553.8.1.el8_10, +15 more
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2024:4211
  • Red Hat Enterprise Linux BaseOS AUS (v.8.6) perf 4.18.0-372.118.1.el8_6, kernel 4.18.0-372.118.1.el8_6, bpftool 4.18.0-372.118.1.el8_6, kernel-core 4.18.0-372.118.1.el8_6, kernel-tools 4.18.0-372.118.1.el8_6, python3-perf 4.18.0-372.118.1.el8_6, +8 more Red Hat Enterprise Linux BaseOS E4S (v.8.6) perf 4.18.0-372.118.1.el8_6, kernel 4.18.0-372.118.1.el8_6, bpftool 4.18.0-372.118.1.el8_6, kernel-core 4.18.0-372.118.1.el8_6, kernel-tools 4.18.0-372.118.1.el8_6, python3-perf 4.18.0-372.118.1.el8_6, +15 more
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2024:5281
  • Red Hat Enterprise Linux BaseOS EUS (v.8.8) perf 4.18.0-477.64.1.el8_8, kernel 4.18.0-477.64.1.el8_8, bpftool 4.18.0-477.64.1.el8_8, kernel-core 4.18.0-477.64.1.el8_8, kernel-tools 4.18.0-477.64.1.el8_8, python3-perf 4.18.0-477.64.1.el8_8, +15 more
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2024:4740
  • Red Hat Enterprise Linux BaseOS TUS (v.8.6) perf 4.18.0-372.118.1.el8_6, kernel 4.18.0-372.118.1.el8_6, bpftool 4.18.0-372.118.1.el8_6, kernel-core 4.18.0-372.118.1.el8_6, kernel-tools 4.18.0-372.118.1.el8_6, python3-perf 4.18.0-372.118.1.el8_6, +8 more
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2024:5281
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.8.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.8.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.8.1.el8_10
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2024:4211
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-kvm 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-core 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-modules 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-debug-kvm 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-debug-core 4.18.0-553.8.1.rt7.349.el8_10, +4 more Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-core 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-modules 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-debug-core 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-debug-modules 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-modules-extra 4.18.0-553.8.1.rt7.349.el8_10, +2 more
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2024:4352
  • 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 Red Hat Enterprise Linux BaseOS (v. 8) kernel-headers 4.18.0-553.8.1.el8_10, kernel-cross-headers 4.18.0-553.8.1.el8_10 Red Hat Enterprise Linux BaseOS AUS (v.8.6) kernel-headers 4.18.0-372.118.1.el8_6, kernel-cross-headers 4.18.0-372.118.1.el8_6 Red Hat Enterprise Linux BaseOS E4S (v.8.6) kernel-headers 4.18.0-372.118.1.el8_6, kernel-cross-headers 4.18.0-372.118.1.el8_6
    +1 more products
    Red Hat Enterprise Linux BaseOS TUS (v.8.6) kernel-headers 4.18.0-372.118.1.el8_6, kernel-cross-headers 4.18.0-372.118.1.el8_6
    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 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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.