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High · 7.8 CVE-2025-38614 EUVD-2025-25367GHSA-grcg-mgx8-mfvf

eventpoll: Fix semi-unbounded recursion

Published Aug 19, 2025 · Updated Nov 10, 2026 · Assigned by Linux

Vendor: Linux Product: Linux Package: kernel 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-5.15 Package: linux-aws-5.19 Package: linux-aws-5.3 Package: linux-aws-5.4 Package: linux-aws-5.8 Package: linux-aws-6.14 Package: linux-aws-6.2 Package: linux-aws-6.5 Package: linux-aws-6.8 Package: linux-aws-fips Package: linux-aws-hwe Package: linux-azure Package: linux-azure-4.15 Package: linux-azure-5.11 Package: linux-azure-5.13 Package: linux-azure-5.15 Package: linux-azure-5.19 Package: linux-azure-5.3 Package: linux-azure-5.4 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-6.8 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-fde-6.8 Package: linux-azure-fips Package: linux-azure-nvidia Package: linux-azure-nvidia-6.14 Package: linux-bluefield Package: linux-fips Package: linux-gcp Package: linux-gcp-4.15 Package: linux-gcp-5.11 Package: linux-gcp-5.13 Package: linux-gcp-5.15 Package: linux-gcp-5.19 Package: linux-gcp-5.3 Package: linux-gcp-5.4 Package: linux-gcp-5.8 Package: linux-gcp-6.11 Package: linux-gcp-6.14 Package: linux-gcp-6.2 Package: linux-gcp-6.5 Package: linux-gcp-6.8 Package: linux-gcp-fips 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-5.15 Package: linux-hwe-5.19 Package: linux-hwe-5.4 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-6.8 Package: linux-hwe-edge Package: linux-ibm Package: linux-ibm-5.15 Package: linux-ibm-5.4 Package: linux-ibm-6.8 Package: linux-intel Package: linux-intel-5.13 Package: linux-intel-iot-realtime Package: linux-intel-iotg Package: linux-intel-iotg-5.15 Package: linux-iot Package: linux-kvm Package: linux-lowlatency Package: linux-lowlatency-hwe-5.15 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-lowlatency-hwe-6.8 Package: linux-lts-xenial Package: linux-nvidia Package: linux-nvidia-6.11 Package: linux-nvidia-6.2 Package: linux-nvidia-6.5 Package: linux-nvidia-6.8 Package: linux-nvidia-lowlatency Package: linux-nvidia-tegra Package: linux-nvidia-tegra-5.15 Package: linux-nvidia-tegra-igx 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-6.5 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-5.15 Package: linux-oracle-5.3 Package: linux-oracle-5.4 Package: linux-oracle-5.8 Package: linux-oracle-6.14 Package: linux-oracle-6.5 Package: linux-oracle-6.8 Package: linux-raspi Package: linux-raspi-5.4 Package: linux-raspi-realtime Package: linux-raspi2 Package: linux-realtime Package: linux-realtime-6.14 Package: linux-realtime-6.8 Package: linux-riscv Package: linux-riscv-5.11 Package: linux-riscv-5.15 Package: linux-riscv-5.19 Package: linux-riscv-5.8 Package: linux-riscv-6.14 Package: linux-riscv-6.5 Package: linux-riscv-6.8 Package: linux-starfive-5.19 Package: linux-starfive-6.2 Package: linux-starfive-6.5 Package: linux-vmware Package: linux-xilinx Package: linux-xilinx-zynqmp Platform: Linux Ecosystem: Azure Linux Ecosystem: Debian Ecosystem: Ubuntu

Description

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

eventpoll: Fix semi-unbounded recursion

Ensure that epoll instances can never form a graph deeper than
EP_MAX_NESTS+1 links.

Currently, ep_loop_check_proc() ensures that the graph is loop-free and
does some recursion depth checks, but those recursion depth checks don't
limit the depth of the resulting tree for two reasons:

- They don't look upwards in the tree.
- If there are multiple downwards paths of different lengths, only one of
the paths is actually considered for the depth check since commit
28d82dc1c4ed ("epoll: limit paths").

Essentially, the current recursion depth check in ep_loop_check_proc() just
serves to prevent it from recursing too deeply while checking for loops.

A more thorough check is done in reverse_path_check() after the new graph
edge has already been created; this checks, among other things, that no
paths going upwards from any non-epoll file with a length of more than 5
edges exist. However, this check does not apply to non-epoll files.

As a result, it is possible to recurse to a depth of at least roughly 500,
tested on v6.15. (I am unsure if deeper recursion is possible; and this may
have changed with commit 8c44dac8add7 ("eventpoll: Fix priority inversion
problem").)

To fix it:

1. In ep_loop_check_proc(), note the subtree depth of each visited node,
and use subtree depths for the total depth calculation even when a subtree
has already been visited.
2. Add ep_get_upwards_depth_proc() for similarly determining the maximum
depth of an upwards walk.
3. In ep_loop_check(), use these values to limit the total path length
between epoll nodes to EP_MAX_NESTS edges.

Affected products

VendorProductAffectedFixed
Linux Linux 2.6.32.30 – < 2.6.33, 2.6.33.8 – < 2.6.34, 2.6.34.10 – < 2.6.35, 2.6.35.12 – < 2.6.36, 2.6.37.3 – < 2.6.38, 2.6.38 2.6.33

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 6.16.3-1 —
Debian 13 linux 6.12.43-1 —
Debian 12 linux 6.1.153-1 DSA-6009-1
Debian 11 linux-6.1 6.1.153-1~deb11u1 DLA-4328-1
ReleasePackageFixed inAdvisory
Ubuntu Nvidia-BlueField 24.04 LTS linux-bluefield 6.8.0-1016.20 —
Ubuntu Nvidia-BlueField 22.04 LTS linux-bluefield 5.15.0-1081.83 —
Ubuntu 25.10 linux-azure-fde No fix yet —
Ubuntu 24.04 LTS linux 6.8.0-100.100 USN-8028-1
Ubuntu 24.04 LTS linux-aws +1 6.8.0-1046.49 USN-8028-5
Ubuntu 24.04 LTS linux-azure 6.8.0-1046.52 USN-8074-1
Ubuntu 24.04 LTS linux-azure-fde 6.8.0-1046.53 —
Ubuntu 24.04 LTS linux-azure-nvidia 6.8.0-1039.42 —
Ubuntu 24.04 LTS linux-gcp 6.8.0-1047.50 USN-8031-3
Ubuntu 24.04 LTS linux-gke 6.8.0-1043.48 USN-8031-3
Ubuntu 24.04 LTS linux-gkeop 6.8.0-1030.33 USN-8028-5
Ubuntu 24.04 LTS linux-ibm 6.8.0-1044.44 USN-8028-8
Ubuntu 24.04 LTS linux-intel +19 No fix yet —
Ubuntu 24.04 LTS linux-lowlatency 6.8.0-100.100.1 USN-8052-1
Ubuntu 24.04 LTS linux-nvidia-lowlatency 6.8.0-1046.49.1 USN-8028-7
Ubuntu 24.04 LTS linux-nvidia-tegra 6.8.0-1020.20 —
Ubuntu 24.04 LTS linux-oracle 6.8.0-1043.44 USN-8028-5
Ubuntu 24.04 LTS linux-raspi 6.8.0-1047.51 USN-8028-1
Ubuntu 24.04 LTS linux-xilinx 6.8.0-1023.24 USN-8052-2
Ubuntu 22.04 LTS linux +1 5.15.0-163.173 USN-7909-1
Ubuntu 22.04 LTS linux-aws 5.15.0-1097.104 USN-7909-1
Ubuntu 22.04 LTS linux-aws-6.8 +1 6.8.0-1046.49~22.04.1 USN-8028-5
Ubuntu 22.04 LTS linux-azure 5.15.0-1101.110 USN-7910-2
Ubuntu 22.04 LTS linux-azure-6.8 6.8.0-1051.57~22.04.1 USN-8126-1
Ubuntu 22.04 LTS linux-azure-fde 5.15.0-1102.111.1 —
Ubuntu 22.04 LTS linux-azure-fde-6.8 6.8.0-1046.53~22.04.1 —
Ubuntu 22.04 LTS linux-gcp 5.15.0-1097.106 USN-7909-4
Ubuntu 22.04 LTS linux-gcp-6.8 6.8.0-1047.50~22.04.2 USN-8031-1
Ubuntu 22.04 LTS linux-gke 5.15.0-1093.99 USN-7909-4
Ubuntu 22.04 LTS linux-gkeop 5.15.0-1080.88 USN-7909-4
Ubuntu 22.04 LTS linux-hwe-6.8 +1 6.8.0-100.100~22.04.1 USN-8028-6
Ubuntu 22.04 LTS linux-ibm +1 5.15.0-1091.94 USN-7909-5, USN-7909-1
Ubuntu 22.04 LTS linux-ibm-6.8 6.8.0-1044.44~22.04.1 USN-8028-8
Ubuntu 22.04 LTS linux-intel-iotg 5.15.0-1092.98 USN-7909-1
Ubuntu 22.04 LTS linux-kvm 5.15.0-1089.94 USN-7933-1
Ubuntu 22.04 LTS linux-lowlatency-hwe-6.8 6.8.0-100.100.1~22.04.1 USN-8028-6
Ubuntu 22.04 LTS linux-nvidia 5.15.0-1092.93 USN-7909-1
Ubuntu 22.04 LTS linux-nvidia-tegra 5.15.0-1049.49 USN-7909-1
Ubuntu 22.04 LTS linux-nvidia-tegra-igx 5.15.0-1038.38 USN-7909-1
Ubuntu 22.04 LTS linux-oracle 5.15.0-1094.100 USN-7909-1
Ubuntu 22.04 LTS linux-oracle-6.8 6.8.0-1043.44~22.04.1 USN-8028-5
Ubuntu 22.04 LTS linux-riscv +32 No fix yet —
Ubuntu 22.04 LTS linux-xilinx-zynqmp 5.15.0-1061.65 USN-7909-1
Show 18 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 20.04 LTS linux-gke +28 No fix yet —
Ubuntu 18.04 LTS linux-gcp +14 No fix yet —
Ubuntu 16.04 LTS linux-hwe-edge No fix yet —
Ubuntu Pro Realtime 24.04 LTS linux-raspi-realtime 6.8.0-2037.38 USN-8028-3
Ubuntu Pro Realtime 24.04 LTS linux-realtime 6.8.1-1041.42 USN-8028-3
Ubuntu Pro Realtime 24.04 LTS linux-realtime-6.14 No fix yet —
Ubuntu Pro Realtime 22.04 LTS linux-intel-iot-realtime 5.15.0-1089.91 USN-7909-2
Ubuntu Pro Realtime 22.04 LTS linux-realtime 5.15.0-1096.105 USN-7909-2
Ubuntu Pro Realtime 22.04 LTS linux-realtime-6.8 6.8.1-1041.42~22.04.1 USN-8028-2
Ubuntu Pro FIPS 20.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro FIPS 18.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro FIPS 16.04 LTS linux-fips No fix yet —
Ubuntu Pro FIPS-updates 24.04 LTS linux-aws-fips 6.8.0-1046.49+fips1 USN-8028-4
Ubuntu Pro FIPS-updates 24.04 LTS linux-azure-fips 6.8.0-1046.52+fips1 USN-8074-2
Ubuntu Pro FIPS-updates 24.04 LTS linux-fips 6.8.0-100.100+fips1 USN-8028-4
Ubuntu Pro FIPS-updates 24.04 LTS linux-gcp-fips 6.8.0-1047.50+fips1 USN-8031-2
Ubuntu Pro FIPS-updates 22.04 LTS linux-aws-fips 5.15.0-1097.104+fips1 USN-7909-3
Ubuntu Pro FIPS-updates 22.04 LTS linux-azure-fips 5.15.0-1101.110+fips1 USN-7910-1
Ubuntu Pro FIPS-updates 22.04 LTS linux-fips 5.15.0-163.173+fips1 USN-7909-3
Ubuntu Pro FIPS-updates 22.04 LTS linux-gcp-fips 5.15.0-1097.106+fips1 USN-7909-3
Ubuntu Pro FIPS-updates 20.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro FIPS-updates 18.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro FIPS-updates 16.04 LTS linux-fips No fix yet —
Ubuntu Pro FIPS-preview 22.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro 20.04 LTS linux +10 No fix yet —
Ubuntu Pro 20.04 LTS linux-aws-5.15 5.15.0-1097.104~20.04.1 USN-7909-1
Ubuntu Pro 20.04 LTS linux-azure-5.15 5.15.0-1102.111~20.04.1 USN-7938-1
Ubuntu Pro 20.04 LTS linux-gcp-5.15 5.15.0-1097.106~20.04.1 USN-7909-1
Ubuntu Pro 20.04 LTS linux-hwe-5.15 +1 5.15.0-163.173~20.04.1 USN-7909-1
Ubuntu Pro 20.04 LTS linux-ibm-5.15 5.15.0-1091.94~20.04.1 USN-7909-1
Ubuntu Pro 20.04 LTS linux-intel-iotg-5.15 5.15.0-1092.98~20.04.1 USN-7909-1
Ubuntu Pro 20.04 LTS linux-nvidia-tegra-5.15 5.15.0-1049.49~20.04.1 USN-7909-1
Ubuntu Pro 20.04 LTS linux-oracle-5.15 5.15.0-1094.100~20.04.1 USN-7909-1
Ubuntu Pro 20.04 LTS linux-riscv-5.15 5.15.0-1092.96~20.04.1 —
Ubuntu Pro 18.04 LTS linux +12 No fix yet —
Ubuntu Pro 16.04 LTS linux +7 No fix yet —
Ubuntu Pro 14.04 LTS linux +3 No fix yet —
ReleasePackageFixed inAdvisory
RHEL 10 kernel-modules-extra-matched 6.12.0-124.11.1.el10_1 RHSA-2025:21463
RHEL 10 rv +77 6.12.0-55.40.1.el10_0 RHSA-2025:21463, RHSA-2025:18318
RHEL 9 rv +77 5.14.0-570.52.1.el9_6 RHSA-2025:17760
Show 3 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
RHEL 9.4 EUS bpftool 7.3.0-427.96.1.el9_4 RHSA-2025:19104
RHEL 9.4 EUS rv +64 5.14.0-427.96.1.el9_4 RHSA-2025:19104
RHEL 9.2 E4S bpftool 7.0.0-284.146.1.el9_2 RHSA-2025:21051
RHEL 9.2 E4S kernel-rt +14 5.14.0-284.146.1.rt14.431.el9_2 RHSA-2025:21128
RHEL 9.2 E4S perf +47 5.14.0-284.146.1.el9_2 RHSA-2025:21051
RHEL 9.0 E4S kernel-rt +12 5.14.0-70.151.1.rt21.223.el9_0 RHSA-2025:19268
RHEL 9.0 E4S perf +28 5.14.0-70.151.1.el9_0 RHSA-2025:19492

AlmaLinux

Errata ↗
ReleasePackageFixed inAdvisory
AlmaLinux 10 kernel-doc +1 6.12.0-55.40.1.el10_0 ALSA-2025:18318
AlmaLinux 9 rv +75 5.14.0-570.52.1.el9_6 ALSA-2025:17760

Rocky Linux

Errata ↗
ReleasePackageFixed inAdvisory
Rocky Linux 10 kernel 6.12.0-55.40.1.el10_0 RLSA-2025:18318
Rocky Linux 9 kernel 5.14.0-570.52.1.el9_6 RLSA-2025:17760
ReleasePackageFixed inAdvisory
SLES 15 SP7 kernel-64kb +6 6.4.0-150700.53.19.1 SUSE-SU-2025:03601-1
SLES 15 SP7 kernel-azure +1 6.4.0-150700.20.15.2 SUSE-SU-2025:03633-1
SLES 15 SP7 kernel-default-base 6.4.0-150700.53.19.1.150700.17.13.1 SUSE-SU-2025:03601-1
SLES 15 SP7 kernel-syms-azure 6.4.0-150700.20.15.1 SUSE-SU-2025:03633-1
SLES 15 SP6 kernel-64kb +6 6.4.0-150600.23.73.1 SUSE-SU-2025:03600-1
SLES 15 SP6 kernel-azure +2 6.4.0-150600.8.52.1 SUSE-SU-2025:03634-1
SLES 15 SP6 kernel-coco +3 6.4.0-15061.32.coco15sp6.1 SUSE-SU-2025:03602-1
SLES 15 SP6 kernel-default-base 6.4.0-150600.23.73.1.150600.12.32.1 SUSE-SU-2025:03600-1
Show 9 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLES for SAP 16.0 kernel-64kb +7 6.12.0-160000.6.1 SUSE-SU-2025:21139-1
SLES for SAP 16.0 kernel-default-base 6.12.0-160000.6.1.160000.2.4 SUSE-SU-2025:21139-1
SLES 16.0 kernel-64kb +7 6.12.0-160000.6.1 SUSE-SU-2025:21179-1, SUSE-SU-2025:21139-1
SLES 16.0 kernel-default-base 6.12.0-160000.6.1.160000.2.4 SUSE-SU-2025:21139-1
SLE Micro 6.2 kernel-default-base 6.12.0-160000.6.1.160000.2.4 SUSE-SU-2025:21074-1
SLE Micro 6.2 kernel-rt +5 6.12.0-160000.6.1 SUSE-SU-2026:20560-1, SUSE-SU-2025:21074-1
SLE Micro 6.1 kernel-default-base 6.4.0-35.1.21.12 SUSE-SU-2025:20861-1
SLE Micro 6.1 kernel-rt +1 6.4.0-37.1 SUSE-SU-2025:20898-1
SLE Micro 6.1 kernel-source +2 6.4.0-35.1 SUSE-SU-2025:20861-1
SLE Micro 6.0 kernel-default-base 6.4.0-35.1.21.12 SUSE-SU-2025:20851-1
SLE Micro 6.0 kernel-rt +1 6.4.0-37.1 SUSE-SU-2025:20870-1
SLE Micro 6.0 kernel-source +2 6.4.0-35.1 SUSE-SU-2025:20851-1
SLE Live Patching 15 SP7 kernel-default 6.4.0-150700.53.19.1 SUSE-SU-2025:03601-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7-RT_Update_5 1-150700.1.3.1 SUSE-SU-2025:3725-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7_Update_5 1-150700.15.3.1 SUSE-SU-2025:03601-1
SLE Live Patching 15 SP6 kernel-default 6.4.0-150600.23.73.1 SUSE-SU-2025:03600-1
SLE Live Patching 15 SP6 kernel-livepatch-SLE15-SP6-RT_Update_16 1-150600.1.3.1 SUSE-SU-2025:3751-1
SLE Live Patching 15 SP6 kernel-livepatch-SLE15-SP6_Update_16 1-150600.13.3.1 SUSE-SU-2025:03600-1
SUSE Real Time Module 15 SP7 kernel-rt +2 6.4.0-150700.7.19.1 SUSE-SU-2025:3725-1
SUSE Real Time Module 15 SP6 kernel-rt +3 6.4.0-150600.10.55.1 SUSE-SU-2025:3751-1
ReleasePackageFixed inAdvisory
openSUSE Leap 16.0 kernel-default-base 6.12.0-160000.6.1.160000.2.4 openSUSE-SU-2025:20081-1
openSUSE Leap 16.0 kernel-rt +10 6.12.0-160000.6.1 openSUSE-SU-2025:20081-1
openSUSE Leap 15.6 dtb-aarch64 +10 6.4.0-150600.23.73.1 SUSE-SU-2025:03600-1
openSUSE Leap 15.6 kernel-azure +2 6.4.0-150600.8.52.1 SUSE-SU-2025:03634-1
openSUSE Leap 15.6 kernel-default-base 6.4.0-150600.23.73.1.150600.12.32.1 SUSE-SU-2025:03600-1
openSUSE Leap 15.6 kernel-rt +3 6.4.0-150600.10.55.1 SUSE-SU-2025:3751-1

Amazon Linux

ReleasePackageFixed inAdvisory
Amazon Linux 2023 kernel-livepatch-6.12.46-66.121 +1 1:1.0-0.amzn2023 ALAS2023-2025-1208, ALAS2023-2025-1186
Amazon Linux 2023 perf +14 1:6.1.150-174.273.amzn2023 ALAS2023-2025-1186
Amazon Linux 2023 perf6.12 +14 1:6.12.46-66.121.amzn2023 ALAS2023-2025-1208

Azure Linux

ReleasePackageFixed inAdvisory
Azure Linux 3 kernel 6.6.104.2-1 —
Azure Linux 2 (CBL-Mariner) kernel 5.15.200.1-1 —

Oracle Linux

ReleasePackageFixed inAdvisory
Oracle Linux 10 kernel-modules-extra-matched 6.12.0-124.13.1.el10_1 ELSA-2025-21463
Oracle Linux 10 rv +28 6.12.0-55.40.1.0.1.el10_0 ELSA-2025-21463, ELSA-2025-18318
Oracle Linux 9 kernel-uek +34 6.12.0-104.43.4.2.el10uek ELSA-2025-20662
Oracle Linux 9 rv +28 5.14.0-570.52.1.0.1.el9_6 ELSA-2025-17760
Oracle Linux 8 bpftool +18 5.15.0-314.193.5.3.el9uek ELSA-2025-25757

Advisories 50

References