CVE-2024-41932: sched: fix warning in sched_setaffinity
Description
In the Linux kernel, the following vulnerability has been resolved:
sched: fix warning in sched_setaffinity
Commit 8f9ea86fdf99b added some logic to sched_setaffinity that included
a WARN when a per-task affinity assignment races with a cpuset update.
Specifically, we can have a race where a cpuset update results in the
task affinity no longer being a subset of the cpuset. That's fine; we
have a fallback to instead use the cpuset mask. However, we have a WARN
set up that will trigger if the cpuset mask has no overlap at all with
the requested task affinity. This shouldn't be a warning condition; its
trivial to create this condition.
Reproduced the warning by the following setup:
- $PID inside a cpuset cgroup
- another thread repeatedly switching the cpuset cpus from 1-2 to just 1
- another thread repeatedly setting the $PID affinity (via taskset) to 2
Classification
CVE ID: CVE-2024-41932
Affected Products
Vendor: Linux
Product: Linux
Exploit Prediction Scoring System (EPSS)
EPSS Score: 0.04% (probability of being exploited)
EPSS Percentile: 11.47% (scored less or equal to compared to others)
EPSS Date: 2025-02-09 (when was this score calculated)
References
https://git.kernel.org/stable/c/5c3fb75f538cfcb886f6dfeb497d99fc2f263ee6https://git.kernel.org/stable/c/70ee7947a29029736a1a06c73a48ff37674a851b