Description

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

mptcp: sysctl: blackhole timeout: avoid using current->nsproxy

As mentioned in the previous commit, 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 'pernet' structure can be obtained from the table->data using
container_of().

Classification

CVE ID: CVE-2025-21641

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.04% (probability of being exploited)

EPSS Percentile: 11.67% (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/4c74fbdc5ab95b13945be01e6065940b68222db7
https://git.kernel.org/stable/c/92cf7a51bdae24a32c592adcdd59a773ae149289

Timeline