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Unscored CVE-2025-40305 EUVD-2025-201640GHSA-jr46-vc8c-pm2x

9p/trans_fd: p9_fd_request: kick rx thread if EPOLLIN

Published Dec 8, 2025 · Updated May 11, 2026 · Assigned by Linux

Vendor: Linux Product: Linux Package: linux Package: linux Package: linux-allwinner-5.19 Package: linux-aws Package: linux-aws-5.0 Package: linux-aws-5.11 Package: linux-aws-5.13 Package: linux-aws-5.19 Package: linux-aws-5.3 Package: linux-aws-5.8 Package: linux-aws-6.14 Package: linux-aws-6.17 Package: linux-aws-6.2 Package: linux-aws-6.5 Package: linux-azure Package: linux-azure-5.11 Package: linux-azure-5.13 Package: linux-azure-5.19 Package: linux-azure-5.3 Package: linux-azure-5.8 Package: linux-azure-6.11 Package: linux-azure-6.14 Package: linux-azure-6.2 Package: linux-azure-6.5 Package: linux-azure-edge Package: linux-azure-fde Package: linux-azure-fde-5.19 Package: linux-azure-fde-6.14 Package: linux-azure-fde-6.2 Package: linux-azure-nvidia-6.14 Package: linux-gcp Package: linux-gcp-5.11 Package: linux-gcp-5.13 Package: linux-gcp-5.19 Package: linux-gcp-5.3 Package: linux-gcp-5.8 Package: linux-gcp-6.11 Package: linux-gcp-6.14 Package: linux-gcp-6.17 Package: linux-gcp-6.2 Package: linux-gcp-6.5 Package: linux-gke Package: linux-gke-4.15 Package: linux-gke-5.15 Package: linux-gke-5.4 Package: linux-gkeop Package: linux-gkeop-5.15 Package: linux-gkeop-5.4 Package: linux-hwe Package: linux-hwe-5.11 Package: linux-hwe-5.13 Package: linux-hwe-5.19 Package: linux-hwe-5.8 Package: linux-hwe-6.11 Package: linux-hwe-6.14 Package: linux-hwe-6.2 Package: linux-hwe-6.5 Package: linux-hwe-edge Package: linux-intel-5.13 Package: linux-intel-iot-realtime Package: linux-lowlatency-hwe-5.19 Package: linux-lowlatency-hwe-6.11 Package: linux-lowlatency-hwe-6.2 Package: linux-lowlatency-hwe-6.5 Package: linux-nvidia-6.11 Package: linux-nvidia-6.17 Package: linux-nvidia-6.2 Package: linux-nvidia-6.5 Package: linux-oem Package: linux-oem-5.10 Package: linux-oem-5.13 Package: linux-oem-5.14 Package: linux-oem-5.17 Package: linux-oem-5.6 Package: linux-oem-6.0 Package: linux-oem-6.1 Package: linux-oem-6.11 Package: linux-oem-6.14 Package: linux-oem-6.17 Package: linux-oem-6.5 Package: linux-oem-6.8 Package: linux-oracle Package: linux-oracle-5.0 Package: linux-oracle-5.11 Package: linux-oracle-5.13 Package: linux-oracle-5.3 Package: linux-oracle-5.8 Package: linux-oracle-6.14 Package: linux-oracle-6.17 Package: linux-oracle-6.5 Package: linux-raspi Package: linux-raspi-realtime Package: linux-raspi2 Package: linux-realtime Package: linux-realtime-6.14 Package: linux-realtime-6.17 Package: linux-riscv Package: linux-riscv-5.11 Package: linux-riscv-5.19 Package: linux-riscv-5.8 Package: linux-riscv-6.14 Package: linux-riscv-6.5 Package: linux-starfive-5.19 Package: linux-starfive-6.2 Package: linux-starfive-6.5 Package: linux-vmware Platform: Linux Ecosystem: Debian Ecosystem: Ubuntu

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.

Affected products

VendorProductAffectedFixed
Linux Linux 6.14 6.17.8

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 linux 6.17.8-1 —
ReleasePackageFixed inAdvisory
Ubuntu 25.10 linux 6.17.0-14.14 USN-8029-1
Ubuntu 25.10 linux-aws +2 6.17.0-1007.7 USN-8030-1, USN-8029-2
Ubuntu 25.10 linux-azure +1 6.17.0-1008.8 USN-8029-3, USN-8029-1
Ubuntu 25.10 linux-azure-fde No fix yet —
Ubuntu 25.10 linux-realtime 6.17.0-1006.7 USN-8029-1
Ubuntu 25.10 linux-riscv 6.17.0-14.14.1 —
Ubuntu 24.04 LTS linux 6.8.0-106.106 USN-8095-1
Ubuntu 24.04 LTS linux-aws 6.8.0-1050.53 USN-8095-1
Ubuntu 24.04 LTS linux-aws-6.17 +1 6.17.0-1007.7~24.04.1 —
Ubuntu 24.04 LTS linux-azure 6.8.0-1051.57 USN-8125-1
Ubuntu 24.04 LTS linux-gcp 6.8.0-1052.55 USN-8095-1
Ubuntu 24.04 LTS linux-gcp-6.17 6.17.0-1008.8~24.04.1 —
Ubuntu 24.04 LTS linux-gke 6.8.0-1048.53 USN-8095-1
Ubuntu 24.04 LTS linux-gkeop 6.8.0-1035.38 USN-8095-1
Ubuntu 24.04 LTS linux-ibm 6.8.0-1049.49 USN-8095-1
Ubuntu 24.04 LTS linux-lowlatency 6.8.0-106.106.1 USN-8095-1
Ubuntu 24.04 LTS linux-nvidia 6.8.0-1049.52 USN-8100-1
Ubuntu 24.04 LTS linux-nvidia-6.17 6.17.0-1008.8 —
Ubuntu 24.04 LTS linux-nvidia-lowlatency 6.8.0-1049.52.1 USN-8100-1
Ubuntu 24.04 LTS linux-oem-6.17 6.17.0-1011.11 USN-8048-1
Ubuntu 24.04 LTS linux-oracle 6.8.0-1047.48 USN-8095-1
Ubuntu 24.04 LTS linux-raspi 6.8.0-1050.54 USN-8095-5
Ubuntu 24.04 LTS linux-riscv +18 No fix yet —
Ubuntu 24.04 LTS linux-xilinx 6.8.0-1029.30 USN-8261-1
Ubuntu 22.04 LTS linux-aws-6.8 6.8.0-1050.53~22.04.1 USN-8095-4
Ubuntu 22.04 LTS linux-azure-6.8 6.8.0-1051.57~22.04.1 USN-8126-1
Ubuntu 22.04 LTS linux-gcp-6.8 6.8.0-1052.55~22.04.1 USN-8095-1
Ubuntu 22.04 LTS linux-hwe-6.8 6.8.0-106.106~22.04.1 USN-8095-1
Ubuntu 22.04 LTS linux-ibm-6.8 6.8.0-1049.49~22.04.1 USN-8095-1
Ubuntu 22.04 LTS linux-lowlatency-hwe-6.8 6.8.0-106.106.1~22.04.1 USN-8095-1
Ubuntu 22.04 LTS linux-nvidia-6.8 6.8.0-1049.52~22.04.1 USN-8100-1
Ubuntu 22.04 LTS linux-oracle-6.8 6.8.0-1047.48~22.04.1 USN-8095-1
Ubuntu 22.04 LTS linux-riscv +32 No fix yet —
Ubuntu 20.04 LTS linux-gke +28 No fix yet —
Ubuntu 18.04 LTS linux-gcp +14 No fix yet —
Show 4 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 16.04 LTS linux-hwe-edge No fix yet —
Ubuntu Pro Realtime 24.04 LTS linux-raspi-realtime 6.8.0-2040.41 USN-8095-5
Ubuntu Pro Realtime 24.04 LTS linux-realtime 6.8.1-1045.46 USN-8095-3
Ubuntu Pro Realtime 24.04 LTS linux-realtime-6.14 No fix yet —
Ubuntu Pro Realtime 24.04 LTS linux-realtime-6.17 6.17.0-1006.7~24.04.1 —
Ubuntu Pro Realtime 22.04 LTS linux-realtime-6.8 6.8.1-1045.46~22.04.1 USN-8095-3
Ubuntu Pro FIPS-updates 24.04 LTS linux-aws-fips 6.8.0-1050.53+fips1 USN-8095-2
Ubuntu Pro FIPS-updates 24.04 LTS linux-azure-fips 6.8.0-1052.58+fips1 USN-8165-1
Ubuntu Pro FIPS-updates 24.04 LTS linux-fips 6.8.0-106.106+fips1 USN-8095-2
Ubuntu Pro FIPS-updates 24.04 LTS linux-gcp-fips 6.8.0-1052.55+fips1 USN-8095-2

Oracle Linux

ReleasePackageFixed inAdvisory
Oracle Linux 9 kernel-uek +34 6.12.0-107.59.3.2.el10uek ELSA-2026-50006

Advisories 17

References