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Fencer Vulns
high 7.8

CVE-2026-72072 json

net/mlx5e: macsec: fix use-after-free of metadata_dst on RX SC delete

published 2026-08-15 2 mo ago modified 2026-10-19 20 d ago also EUVD-2026-59030

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 6%
public exploits
0
none known

Summary

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

net/mlx5e: macsec: fix use-after-free of metadata_dst on RX SC delete

When an offloaded MACsec RX SC is deleted, macsec_del_rxsc_ctx() freed the per-SC metadata_dst with metadata_dst_free(), which kfree()s the object unconditionally and ignores the dst reference count. The RX datapath in mlx5e_macsec_offload_handle_rx_skb() looks up the SC under rcu_read_lock() via xa_load(), takes a reference with dst_hold() and attaches the dst to the skb with skb_dst_set(). A reader that already obtained the rx_sc pointer can race with the delete path and operate on freed memory.

Fix the owner side by dropping the reference with dst_release() instead of freeing unconditionally, and convert the RX datapath to dst_hold_safe() so a reader racing the SC delete cannot attach a dst whose last reference was just dropped; only attach it when a reference was actually taken.

mlx5e_macsec_add_rxsc() also published sc_xarray_element via xa_alloc() before rx_sc->md_dst was allocated and initialised, so a datapath reader that looked the SC up by fs_id could observe rx_sc with md_dst still NULL or, on weakly-ordered architectures, a non-NULL md_dst pointer whose contents were not yet visible. NULL-check the xa_load() result and md_dst on the datapath, and reorder add_rxsc() so the xa_alloc() publish happens only after md_dst is fully initialised; the xarray RCU publish then pairs with the rcu_read_lock()/xa_load() in the datapath.

Note: macsec_del_rxsc_ctx() also kfree()s rx_sc->sc_xarray_element without an RCU grace period while the same datapath reads it under rcu_read_lock(); that is a separate pre-existing issue left to a follow-up patch.

Found by 0sec automated security-research tooling (https://0sec.ai).

Patch / fix

  • Linux Linux 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.5, 7.2
  • linux Debian 12 6.1.180-1
  • linux Debian 13 6.12.100-1
  • linux Debian 14 7.1.5-1

debian advisories DEBIAN-CVE-2026-72072

  • linux Ubuntu 24.04 LTS 6.8.0-147.147
  • linux Ubuntu 26.04 LTS 7.0.0-38.38
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1067.70
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1014.14
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1071.79
  • linux-gcp Ubuntu 26.04 LTS 7.0.0-1014.14
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1066.74
  • linux-gke Ubuntu 26.04 LTS 7.0.0-1008.9

ubuntu advisories UBUNTU-CVE-2026-72072

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 9 5.14.0-687.50.1.el9_8
  • rv RHEL 9 5.14.0-687.50.1.el9_8
  • perf RHEL 9 5.14.0-687.50.1.el9_8
  • rtla RHEL 9 5.14.0-687.50.1.el9_8
  • libperf RHEL 9 5.14.0-687.50.1.el9_8
  • kernel-rt RHEL 9 5.14.0-687.50.1.el9_8
  • kernel-64k RHEL 9 5.14.0-687.50.1.el9_8
  • kernel-core RHEL 9 5.14.0-687.50.1.el9_8

red hat advisories RHSA-2026:70459

  • kernel-64kb SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS, SLE High Performance Computing 15 SP5-ESPOS 5.14.21-150500.55.189.1
  • kernel-syms SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 5.14.21-150500.55.189.1
  • kernel-source SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +2 more 5.14.21-150500.55.189.1
  • kernel-default SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +3 more 5.14.21-150500.55.189.1
  • kernel-obs-build SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 5.14.21-150500.55.189.1
  • kernel-default-base SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +2 more 5.14.21-150500.55.189.1.150500.6.87.4
  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.81.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.81.1

suse advisories SUSE-SU-2026:4595-1SUSE-SU-2026:4254-1SUSE-SU-2026:4369-1SUSE-SU-2026:4347-1SUSE-SU-2026:23887-1SUSE-SU-2026:23902-1

  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.38.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-azure openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.38.1

opensuse advisories openSUSE-SU-2026:21910-1

  • kernel AlmaLinux 9 5.14.0-687.50.1.el9_8
  • rv AlmaLinux 9 5.14.0-687.50.1.el9_8
  • perf AlmaLinux 9 5.14.0-687.50.1.el9_8
  • rtla AlmaLinux 9 5.14.0-687.50.1.el9_8
  • libperf AlmaLinux 9 5.14.0-687.50.1.el9_8
  • kernel-rt AlmaLinux 9 5.14.0-687.50.1.el9_8
  • kernel-64k AlmaLinux 9 5.14.0-687.50.1.el9_8
  • kernel-core AlmaLinux 9 5.14.0-687.50.1.el9_8

almalinux advisories ALSA-2026:70459

  • kernel Rocky Linux 9 5.14.0-687.50.1.el9_8

rocky linux advisories RLSA-2026:70459

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-2026-72072 updated cvss 5.3

kernel: net/mlx5e: macsec: fix use-after-free of metadata_dst on RX SC delete

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 10 kernel
    affected: workaround, no fix available
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-687.50.1.el9_8, perf 5.14.0-687.50.1.el9_8, rtla 5.14.0-687.50.1.el9_8, python3-perf 5.14.0-687.50.1.el9_8, kernel-devel-matched 5.14.0-687.50.1.el9_8, kernel-64k-devel-matched 5.14.0-687.50.1.el9_8, +7 more Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-687.50.1.el9_8, kernel-64k 5.14.0-687.50.1.el9_8, kernel-core 5.14.0-687.50.1.el9_8, kernel-tools 5.14.0-687.50.1.el9_8, kernel-modules 5.14.0-687.50.1.el9_8, kernel-64k-core 5.14.0-687.50.1.el9_8, +27 more Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-687.50.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.50.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.50.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.50.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.50.1.el9_8 Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-687.50.1.el9_8, kernel-rt-64k 5.14.0-687.50.1.el9_8, kernel-rt-core 5.14.0-687.50.1.el9_8, kernel-rt-modules 5.14.0-687.50.1.el9_8, kernel-rt-64k-core 5.14.0-687.50.1.el9_8, kernel-rt-debug-core 5.14.0-687.50.1.el9_8, +14 more Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-687.50.1.el9_8, kernel-rt-core 5.14.0-687.50.1.el9_8, kernel-rt-modules 5.14.0-687.50.1.el9_8, kernel-rt-debug-core 5.14.0-687.50.1.el9_8, kernel-rt-modules-core 5.14.0-687.50.1.el9_8, kernel-rt-debug-modules 5.14.0-687.50.1.el9_8, +4 more
    fixed: vendor fix RHSA-2026:70459
  • 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 Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 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
total
Assessed
23 d ago

Exploit prediction

0.17% chance of exploitation in the next 30 days, higher than 6% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 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.