CVE-2025-21638 Information

Description

In the Linux kernel the following vulnerability has been resolved:

sctp: sysctl: auth_enable: 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 ’net’ structure can be obtained from the table->data using container_of().

Note that table->data could also be used directly but that would increase the size of this fix while ‘sctp.ctl_sock’ still needs to be retrieved from ’net’ structure.

Reference

https://git.kernel.org/stable/c/15649fd5415eda664ef35780c2013adeb5d9c695 https://git.kernel.org/stable/c/1b67030d39f2b00f94ac1f0af11ba6657589e4d3 https://git.kernel.org/stable/c/7ec30c54f339c640aa7e49d7e9f7bbed6bd42bf6 https://git.kernel.org/stable/c/c184bc621e3cef03ac9ba81a50dda2dae6a21d36