CVE-2024-42161: Linux kernel · bpf: Avoid uninitialized value in BPF_CORE_READ_BITFIELD
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 6.3 Medium · fixed in 5.15.0-1069.75~20.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 23:28 UTC
- Patch
- Available – fixed in 5.15.0-1069.75~20.04.1, 5.15.0-1072.81~20.04.1, 5.15.0-1068.76~20.04.1 +54
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 30 Jul 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-7007-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7009-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7019-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7007-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7007-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7009-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7089-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7090-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7089-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7089-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7095-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7089-4 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gkeoppkg:deb/ubuntu/linux-gkeop?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: bpf: Avoid uninitialized value in BPF_CORE_READ_BITFIELD [Changes from V1: - Use a default branch in the switch statement to initialize `val'.] GCC warns that `val' may be used uninitialized in the BPF_CRE_READ_BITFIELD macro, defined in bpf_core_read.h as: [...] unsigned long long val; \ [...] \ switch (__CORE_RELO(s, field, BYTE_SIZE)) { \ case 1: val = *(const unsigned char *)p; break; \ case 2: val = *(const unsigned short *)p; break; \ case 4: val = *(const unsigned int *)p; break; \ case 8: val = *(const unsigned long long *)p; break; \ } \ [...] val; \ } \ This patch adds a default entry in the switch statement that sets `val' to zero in order to avoid the warning, and random values to be used in case __builtin_preserve_field_info returns unexpected values for BPF_FIELD_BYTE_SIZE. Tested in bpf-next master. No regressions.
References
- ubuntu.com/security/CVE-2024-42161 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-42161 (opens in a new tab)
- git.kernel.org/linus/009367099eb61a4fc2af44d4eb06b6b4de7de6db (opens in a new tab)
- git.kernel.org/stable/c/b694989bb13ed5f166e633faa1eb0f21c6d261a6 (opens in a new tab)
- git.kernel.org/stable/c/3364c2ed1c241989847f19cf83e3db903ce689e3 (opens in a new tab)
- git.kernel.org/stable/c/a21d76bd0b0d39518e9a4c19f6cf7c042a974aff (opens in a new tab)
- git.kernel.org/stable/c/7e5471b5efebc30dd0bc035cda86693a5c73d45f (opens in a new tab)
- git.kernel.org/stable/c/ff941a8449e712eaf7efca1a13bfb9afd3d99fc2 (opens in a new tab)
- git.kernel.org/stable/c/009367099eb61a4fc2af44d4eb06b6b4de7de6db (opens in a new tab)
- ubuntu.com/security/notices/USN-7007-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7009-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7019-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7007-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7007-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7009-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7089-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7090-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7089-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7089-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7095-1 (opens in a new tab)