CVE-2024-40905: Linux kernel · ipv6: fix possible race in __fib6_drop_pcpu_from()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 4.7 Medium · fixed in 5.4.0-1132.142~18.04.1 : update Linux kernel when convenient.
Data as of 28 Oct 2026, 11:02 UTC
- Patch
- Available – fixed in 5.4.0-1132.142~18.04.1, 5.4.0-1137.144~18.04.1, 5.4.0-1136.145~18.04.1 +71
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 12 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-6999-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7003-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7003-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7004-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7005-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7006-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7003-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7007-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7008-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7005-2 (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)
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-ibmpkg:deb/ubuntu/linux-ibm?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.
AI-suggested
A patch is available and has been released in multiple fixed Linux kernel versions including 5.4.0-1132.142~18.04.1 and later. Users should update their Linux kernel to one of the fixed versions to remediate this issue. No additional mitigation is required beyond applying the official kernel updates.
Description
CVE-2024-40905 is a race condition vulnerability in the Linux kernel's IPv6 implementation, specifically in the __fib6_drop_pcpu_from() function. The flaw occurs when concurrent CPU accesses lead to a null pointer dereference due to improper synchronization. This can cause a system crash (denial of service). The issue has been fixed by adding proper memory access synchronization primitives (READ_ONCE and RCU locks).
References
- ubuntu.com/security/CVE-2024-40905 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-40905 (opens in a new tab)
- git.kernel.org/linus/b01e1c030770ff3b4fe37fc7cc6bca03f594133f (opens in a new tab)
- git.kernel.org/stable/c/c90af1cced2f669a7b2304584be4ada495eaa0e5 (opens in a new tab)
- git.kernel.org/stable/c/c693698787660c97950bc1f93a8dd19d8307153d (opens in a new tab)
- git.kernel.org/stable/c/a0bc020592b54a8f3fa2b7f244b6e39e526c2e12 (opens in a new tab)
- git.kernel.org/stable/c/2498960dac9b6fc49b6d1574f7cd1a4872744adf (opens in a new tab)
- git.kernel.org/stable/c/7e796c3fefa8b17b30e7252886ae8cffacd2b9ef (opens in a new tab)
- git.kernel.org/stable/c/09e5a5a80e205922151136069e440477d6816914 (opens in a new tab)
- git.kernel.org/stable/c/b01e1c030770ff3b4fe37fc7cc6bca03f594133f (opens in a new tab)
- ubuntu.com/security/notices/USN-6999-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7003-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7003-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7004-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7005-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7006-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7003-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7007-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7008-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7005-2 (opens in a new tab)