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Fencer Vulns
high 7.8

CVE-2024-40996 json

bpf: Avoid splat in pskb_pull_reason

published 2024-07-12 2 y ago modified 2026-06-17 4 mo ago also EUVD-2024-38791

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 20%
public exploits
0
none known

Summary

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

bpf: Avoid splat in pskb_pull_reason

syzkaller builds (CONFIG_DEBUG_NET=y) frequently trigger a debug hint in pskb_may_pull.

We'd like to retain this debug check because it might hint at integer overflows and other issues (kernel code should pull headers, not huge value).

In bpf case, this splat isn't interesting at all: such (nonsensical) bpf programs are typically generated by a fuzzer anyway.

Do what Eric suggested and suppress such warning.

For CONFIG_DEBUG_NET=n we don't need the extra check because pskb_may_pull will do the right thing: return an error without the WARN() backtrace.

Patch / fix

  • Linux Linux 6.1.96, 6.6.36, 6.9, 6.9.7, 6.10
  • linux Debian 12 6.1.99-1
  • linux Debian 14, Debian 13 6.9.7-1

debian advisories DEBIAN-CVE-2024-40996

  • linux Ubuntu 24.04 LTS 6.8.0-44.44
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1015.16
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1014.16
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1010.13
  • linux-ibm Ubuntu 24.04 LTS 6.8.0-1012.12
  • linux-azure Ubuntu 24.04 LTS 6.8.0-1014.16
  • linux-raspi Ubuntu 24.04 LTS 6.8.0-1011.12
  • linux-riscv Ubuntu 24.04 LTS 6.8.0-44.44.1

ubuntu advisories UBUNTU-CVE-2024-40996

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

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-2024-40996 updated cvss 7.8

kernel: bpf: Avoid splat in pskb_pull_reason

  • 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 Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 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

0.28% chance of exploitation in the next 30 days, higher than 20% 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

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.