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.
Analysis and contextual insights are available on OpenCVE Cloud.
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
Sign in to view the affected projects.
| Source | ID | Title |
|---|---|---|
Ubuntu USN |
USN-8029-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8030-1 | Linux kernel (GCP) vulnerabilities |
Ubuntu USN |
USN-8029-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8048-1 | Linux kernel (OEM) vulnerabilities |
Ubuntu USN |
USN-8029-3 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-8095-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8095-2 | Linux kernel (FIPS) vulnerabilities |
Ubuntu USN |
USN-8100-1 | Linux kernel (NVIDIA) vulnerabilities |
Ubuntu USN |
USN-8095-3 | Linux kernel (Real-time) vulnerabilities |
Ubuntu USN |
USN-8095-4 | Linux kernel (AWS) vulnerabilities |
Ubuntu USN |
USN-8125-1 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-8126-1 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-8095-5 | Linux kernel (Raspberry Pi) vulnerabilities |
Ubuntu USN |
USN-8165-1 | Linux kernel (Azure FIPS) vulnerabilities |
Ubuntu USN |
USN-8261-1 | Linux kernel (Xilinx) vulnerabilities |
Fri, 02 Jan 2026 16:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Tue, 09 Dec 2025 00:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Mon, 08 Dec 2025 01:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | 9p/trans_fd: p9_fd_request: kick rx thread if EPOLLIN | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-05-11T21:46:46.952Z
Reserved: 2025-04-16T07:20:57.185Z
Link: CVE-2025-40305
No data.
Status : Deferred
Published: 2025-12-08T01:16:02.700
Modified: 2026-04-15T00:35:42.020
Link: CVE-2025-40305
OpenCVE Enrichment
No data.
No weakness.
Ubuntu USN