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Fencer Vulns
high 7.8

CVE-2024-53125 json

bpf: sync_linked_regs() must preserve subreg_def

published 2024-12-04 23 mo ago modified 2026-10-15 24 d ago also EUVD-2024-51797

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 13%
public exploits
0
none known

Summary

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

bpf: sync_linked_regs() must preserve subreg_def

Range propagation must not affect subreg_def marks, otherwise the following example is rewritten by verifier incorrectly when BPF_F_TEST_RND_HI32 flag is set:

0: call bpf_ktime_get_ns call bpf_ktime_get_ns 1: r0 &= 0x7fffffff after verifier r0 &= 0x7fffffff 2: w1 = w0 rewrites w1 = w0 3: if w0 < 10 goto +0 --------------> r11 = 0x2f5674a6 (r) 4: r1 >>= 32 r11 <<= 32 (r) 5: r0 = r1 r1 |= r11 (r) 6: exit; if w0 < 0xa goto pc+0 r1 >>= 32 r0 = r1 exit

(or zero extension of w1 at (2) is missing for architectures that require zero extension for upper register half).

The following happens w/o this patch: - r0 is marked as not a subreg at (0); - w1 is marked as subreg at (2); - w1 subreg_def is overridden at (3) by copy_register_state(); - w1 is read at (5) but mark_insn_zext() does not mark (2) for zero extension, because w1 subreg_def is not set; - because of BPF_F_TEST_RND_HI32 flag verifier inserts random value for hi32 bits of (2) (marked (r)); - this random value is read at (5).

Patch / fix

  • Linux Linux 5.10.232, 5.15.175, 6.1.121, 6.6.67, 6.11.6, 6.12
  • linux Debian 12 6.1.123-1
  • linux Debian 14, Debian 13 6.11.6-1

debian advisories DEBIAN-CVE-2024-53125

  • linux Ubuntu 22.04 LTS 5.15.0-135.146
  • linux Ubuntu 24.04 LTS 6.8.0-60.63
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1080.87
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1029.31
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1079.88
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1030.32
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1077.83
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1025.29

ubuntu advisories UBUNTU-CVE-2024-53125

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-azure SLE Module for Public Cloud 15 SP6, openSUSE Leap 15.6 6.4.0-150600.8.52.1
  • kernel-syms-azure SLE Module for Public Cloud 15 SP6, openSUSE Leap 15.6 6.4.0-150600.8.52.1
  • kernel-source-azure SLE Module for Public Cloud 15 SP6, openSUSE Leap 15.6 6.4.0-150600.8.52.1
  • kernel-coco SLE Module for Confidential Computing Technical Preview 15 SP6 6.4.0-15061.32.coco15sp6.1
  • kernel-syms-coco SLE Module for Confidential Computing Technical Preview 15 SP6 6.4.0-15061.32.coco15sp6.1
  • kernel-coco_debug SLE Module for Confidential Computing Technical Preview 15 SP6 6.4.0-15061.32.coco15sp6.1
  • kernel-source-coco SLE Module for Confidential Computing Technical Preview 15 SP6 6.4.0-15061.32.coco15sp6.1
  • dtb-aarch64 openSUSE Leap 15.6 6.4.0-150600.23.70.1

suse advisories SUSE-SU-2025:03634-1SUSE-SU-2025:03602-1SUSE-SU-2025:03301-1SUSE-SU-2025:20578-1SUSE-SU-2025:20579-1SUSE-SU-2025:20584-1

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-2024-53125 updated cvss 4.4

kernel: bpf: sync_linked_regs() must preserve subreg_def

  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 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
24 d ago

Exploit prediction

0.23% chance of exploitation in the next 30 days, higher than 13% 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
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

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.