bpf: Check the remaining info_cnt before repeating btf fields

published 2024-11-07 2 y ago modified 2026-08-05 3 mo ago also EUVD-2024-44663

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 9%
public exploits: 0; none known

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

When trying to repeat the btf fields for array of nested struct, it doesn't check the remaining info_cnt. The following splat will be reported when the value of ret * nelems is greater than BTF_FIELDS_MAX:

------------[ cut here ]------------ UBSAN: array-index-out-of-bounds in ../kernel/bpf/btf.c:3951:49 index 11 is out of range for type 'btf_field_info [11]' CPU: 6 UID: 0 PID: 411 Comm: test_progs ...... 6.11.0-rc4+ #1 Tainted: [O]=OOT_MODULE Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ... Call Trace: <TASK> dump_stack_lvl+0x57/0x70 dump_stack+0x10/0x20 ubsan_epilogue+0x9/0x40 __ubsan_handle_out_of_bounds+0x6f/0x80 ? kallsyms_lookup_name+0x48/0xb0 btf_parse_fields+0x992/0xce0 map_create+0x591/0x770 __sys_bpf+0x229/0x2410 __x64_sys_bpf+0x1f/0x30 x64_sys_call+0x199/0x9f0 do_syscall_64+0x3b/0xc0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7fea56f2cc5d ...... </TASK> ---[ end trace ]---

Fix it by checking the remaining info_cnt in btf_repeat_fields() before repeating the btf fields.

Patch / fix

fixed in 1 distros 3 links 2

Linux Linux 6.11.6, 6.12

debian ubuntu opensuse

linux Debian 14, Debian 13 6.11.6-1

debian advisories DEBIAN-CVE-2024-50161

linux-oem-6.11 Ubuntu 24.04 LTS 6.11.0-1015.15

ubuntu advisories UBUNTU-CVE-2024-50161

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-source-longterm openSUSE Tumbleweed 6.12.11-1.1
kernel-source openSUSE Tumbleweed 6.11.8-1.1

opensuse advisories openSUSE-SU-2025:14705-1 openSUSE-SU-2024:14500-1

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-2024-50161 updated 2026-11-07 cvss 4.4

kernel: bpf: Check the remaining info_cnt before repeating btf fields

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: 13 mo ago (2025-10-01)

Exploit prediction

0.20% chance of exploitation in the next 30 days, higher than 9% 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
CISA ADP	3.1	5.5	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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
CNA	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

Weakness

CWE-129 Improper Validation of Array Index

Technology feeds

Linux kernel rss critical rss

References

Sources

CVE List CVE-2024-50161
NVD CVE-2024-50161

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.

Summary