CVE-2024-27390: Linux kernel · ipv6: mcast: remove one synchronize_net() barrier in ipv6_mc_down()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 5.15.0-1063.69~20.04.1 : update Linux kernel when convenient.
Data as of 12 Nov 2026, 19:04 UTC
- Patch
- Available – fixed in 5.15.0-1063.69~20.04.1, 5.15.0-1065.74~20.04.1, 5.15.0-1062.70~20.04.1 +42
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 1 May 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 12 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-6816-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6817-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6820-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6821-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6821-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6817-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6828-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6820-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6821-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6817-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6821-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-6871-1 (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.
Description
In the Linux kernel, the following vulnerability has been resolved: ipv6: mcast: remove one synchronize_net() barrier in ipv6_mc_down() As discussed in the past (commit 2d3916f31891 ("ipv6: fix skb drops in igmp6_event_query() and igmp6_event_report()")) I think the synchronize_net() call in ipv6_mc_down() is not needed. Under load, synchronize_net() can last between 200 usec and 5 ms. KASAN seems to agree as well.
References
- ubuntu.com/security/CVE-2024-27390 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-27390 (opens in a new tab)
- git.kernel.org/linus/17ef8efc00b34918b966388b2af0993811895a8c (opens in a new tab)
- git.kernel.org/stable/c/9d159d6637ccce25f879d662a480541ef4ba3a50 (opens in a new tab)
- git.kernel.org/stable/c/a03ede2282ebbd181bd6f5c38cbfcb5765afcd04 (opens in a new tab)
- git.kernel.org/stable/c/26d4bac55750d535f1f0b8790dc26daf6089e373 (opens in a new tab)
- git.kernel.org/stable/c/7eb06ee5921189812e6b4bfe7b0f1e878be16df7 (opens in a new tab)
- git.kernel.org/stable/c/5da9a218340a2bc804dc4327e5804392e24a0b88 (opens in a new tab)
- git.kernel.org/stable/c/17ef8efc00b34918b966388b2af0993811895a8c (opens in a new tab)
- ubuntu.com/security/notices/USN-6816-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6817-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6820-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6821-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6821-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6817-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6828-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6820-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6821-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6817-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6821-4 (opens in a new tab)