CVE-2024-27390 ipv6: mcast: remove one synchronize_net() barrier in ipv6_mc_down()
An unnecessary synchronization barrier in the Linux kernel IPv6 multicast code can cause significant latency under load, potentially leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-27390?
CVE-2024-27390 is a medium-severity denial of service vulnerability in Linux kernel, published on 1 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2024-27390?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-27390?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2024-27390 being exploited?
There is no known exploitation of CVE-2024-27390 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2024-27390, DEBIAN-CVE-2024-27390, GHSA-49cj-cqm8-6m92, UBUNTU-CVE-2024-27390.