CVE-2025-40305
In the Linux kernel, the following vulnerability has been resolved: 9p/trans_fd: p9_fd_request: kick rx thread if EPOLLIN p9_read_work() doesn't set Rworksched and doesn't do schedule_work(m->rq) if list_empty(&m->req_list). However, if the pipe is full, we need to read more data and this used to work prior to commit aaec5a95d59615 ("pipe_read: don't wake up the writer if the pipe is still full"). p9_read_work() does p9_fd_read() -> ... -> anon_pipe_read() which (before the commit above) triggered the unnecessary wakeup. This wakeup calls p9_pollwake() which kicks p9_poll_workfn() -> p9_poll_mux(), p9_poll_mux() will notice EPOLLIN and schedule_work(&m->rq). This no longer happens after the optimization above, change p9_fd_request() to use p9_poll_mux() instead of only checking for EPOLLOUT.
Affected versions
Linux kernel versions
6.14
and later are affected. Fixed in
6.17.8,
6.18
and their respective stable series.
References
The following references provide additional information about CVE-2025-40305 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/242531004d7de8c159f9bfadebe33fe8060b1046
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PatchKernel patch commithttps://git.kernel.org/stable/c/e8fe3f07a357c39d429e02ca34f740692d88967a
Frequently asked questions
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What is CVE-2025-40305?
CVE-2025-40305 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 6.14 onward and has been patched in 6.17.8 and 6.18. CVE-2025-40305 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2025-40305?
Yes — CVE-2025-40305 has been patched. Fixed versions include 6.17.8 and 6.18. If you are running Linux kernel 6.14 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2025-40305 actively exploited?
No — CVE-2025-40305 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.