NULL Pointer Dereference Affecting kernel-libbpf-devel package, versions <0:6.1.115-126.197.amzn2023


Severity

Recommended
high

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.04% (6th percentile)

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  • Snyk IDSNYK-AMZN2023-KERNELLIBBPFDEVEL-9520208
  • published27 Mar 2025
  • disclosed21 Oct 2024

Introduced: 21 Oct 2024

CVE-2024-49850  (opens in a new tab)
CWE-476  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 kernel-libbpf-devel to version 0:6.1.115-126.197.amzn2023 or higher.
This issue was patched in ALAS2023-2025-794.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-libbpf-devel package and not the kernel-libbpf-devel package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.

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

bpf: correctly handle malformed BPF_CORE_TYPE_ID_LOCAL relos

In case of malformed relocation record of kind BPF_CORE_TYPE_ID_LOCAL referencing a non-existing BTF type, function bpf_core_calc_relo_insn would cause a null pointer deference.

Fix this by adding a proper check upper in call stack, as malformed relocation records could be passed from user space.

Simplest reproducer is a program:

r0 = 0
exit

With a single relocation record:

.insn_off = 0,          /* patch first instruction */
.type_id = 100500,      /* this type id does not exist */
.access_str_off = 6,    /* offset of string &#34;0&#34; */
.kind = BPF_CORE_TYPE_ID_LOCAL,

See the link for original reproducer or next commit for a test case.

CVSS Base Scores

version 3.1