Description

In the Linux kernel, the following vulnerability has been resolved:

sctp: sysctl: udp_port: 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.

Classification

CVE ID: CVE-2025-21637

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.05% (probability of being exploited)

EPSS Percentile: 17.97% (scored less or equal to compared to others)

EPSS Date: 2025-02-17 (when was this score calculated)

References

https://git.kernel.org/stable/c/e919197fb8616331f5dc81e4c3cc3d12769cb725
https://git.kernel.org/stable/c/55627918febdf9d71107a1e68d1528dc591c9a15
https://git.kernel.org/stable/c/5b77d73f3be5102720fb685b9e6900e3500e1096
https://git.kernel.org/stable/c/c10377bbc1972d858eaf0ab366a311b39f8ef1b6

Timeline