CVE-2025-21635: rds: sysctl: rds_tcp_{rcv,snd}buf: avoid using current->nsproxy
In the Linux kernel, the following vulnerability has been resolved:
rds: sysctl: rdstcp{rcv,snd}buf: avoid using current->nsproxy
As mentioned in a previous commit of this series, using the 'net' structure via 'current' is not recommended for different reasons:
- Inconsistency: getting info from the reader's/writer's netns vs only from the opener's netns.
- current->nsproxy can be NULL in some cases, resulting in an 'Oops' (null-ptr-deref), e.g. when the current task is exiting, as spotted by syzbot [1] using acct(2).
The per-netns structure can be obtained from the table->data using containerof(), then the 'net' one can be retrieved from the listen socket (if available).
Other sources
This CVE was automatically created from a reference found in an email or other text. If you are reading this, then this CVE entry is probably erroneous, since this text should be replaced by the official CVE description automatically.
— Launchpad
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2025-21635?
The severity of CVE-2025-21635 is currently rated as moderate.
How do I fix CVE-2025-21635?
To fix CVE-2025-21635, update your Linux kernel to the latest patched version.
What are the potential impacts of CVE-2025-21635?
CVE-2025-21635 can lead to inconsistent behavior in RDS (Reliable Datagram Sockets) operations.
Is CVE-2025-21635 exploitable remotely?
CVE-2025-21635 is not considered to have remote exploit capabilities.
Which version of the Linux kernel is affected by CVE-2025-21635?
The vulnerability affects certain versions of the Linux kernel that utilize the RDS protocol.