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Unscored CVE-2025-38100 EUVD-2025-19842GHSA-hhj3-j6pg-f7mv

x86/iopl: Cure TIF_IO_BITMAP inconsistencies

Published Jul 3, 2025 · Updated Nov 5, 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-5.8 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-azure 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-5.8 Package: linux-azure-6.11 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-6.2 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-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-5.8 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-5.8 Package: linux-hwe-6.11 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-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-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-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-5.8 Package: linux-oracle-6.14 Package: linux-oracle-6.5 Package: linux-oracle-6.8 Package: linux-raspi 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:

x86/iopl: Cure TIF_IO_BITMAP inconsistencies

io_bitmap_exit() is invoked from exit_thread() when a task exists or
when a fork fails. In the latter case the exit_thread() cleans up
resources which were allocated during fork().

io_bitmap_exit() invokes task_update_io_bitmap(), which in turn ends up
in tss_update_io_bitmap(). tss_update_io_bitmap() operates on the
current task. If current has TIF_IO_BITMAP set, but no bitmap installed,
tss_update_io_bitmap() crashes with a NULL pointer dereference.

There are two issues, which lead to that problem:

1) io_bitmap_exit() should not invoke task_update_io_bitmap() when
the task, which is cleaned up, is not the current task. That's a
clear indicator for a cleanup after a failed fork().

2) A task should not have TIF_IO_BITMAP set and neither a bitmap
installed nor IOPL emulation level 3 activated.

This happens when a kernel thread is created in the context of
a user space thread, which has TIF_IO_BITMAP set as the thread
flags are copied and the IO bitmap pointer is cleared.

Other than in the failed fork() case this has no impact because
kernel threads including IO workers never return to user space and
therefore never invoke tss_update_io_bitmap().

Cure this by adding the missing cleanups and checks:

1) Prevent io_bitmap_exit() to invoke task_update_io_bitmap() if
the to be cleaned up task is not the current task.

2) Clear TIF_IO_BITMAP in copy_thread() unconditionally. For user
space forks it is set later, when the IO bitmap is inherited in
io_bitmap_share().

For paranoia sake, add a warning into tss_update_io_bitmap() to catch
the case, when that code is invoked with inconsistent state.

Affected products

VendorProductAffectedFixed
Linux Linux 5.5 5.10.239

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 6.12.35-1 —
Debian 13 linux 6.12.35-1 —
Debian 12 linux 6.1.147-1 DSA-5973-1
Debian 11 linux 5.10.244-1 DLA-4327-1
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 5.15.0-1076.78 —
Ubuntu 25.10 linux-azure-fde No fix yet —
Ubuntu 25.04 linux-azure 6.14.0-1012.12 USN-7770-1
Ubuntu 25.04 linux-raspi 6.14.0-1014.14 USN-7789-2
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-aws-6.14 +1 6.14.0-1013.13~24.04.1 USN-7789-1, USN-7769-3
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-azure-nvidia-6.14 6.14.0-1007.7 —
Ubuntu 24.04 LTS linux-gcp 6.8.0-1047.50 USN-8031-3
Ubuntu 24.04 LTS linux-gcp-6.14 6.14.0-1016.17~24.04.1 USN-7769-1
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-hwe-6.14 6.14.0-32.32~24.04.1 USN-7769-3
Ubuntu 24.04 LTS linux-ibm 6.8.0-1044.44 USN-8028-8
Ubuntu 24.04 LTS linux-intel +10 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-oem-6.14 6.14.0-1012.12 USN-7771-1
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-riscv-6.14 6.14.0-32.32.1~24.04.1 —
Ubuntu 24.04 LTS linux-xilinx 6.8.0-1023.24 USN-8052-2
Show 10 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 22.04 LTS linux +1 5.15.0-156.166 USN-7774-1
Ubuntu 22.04 LTS linux-aws 5.15.0-1092.99 USN-7774-1
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 5.15.0-1096.105 USN-7775-2
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 5.15.0-1096.105.1 —
Ubuntu 22.04 LTS linux-azure-fde-6.8 6.8.0-1046.53~22.04.1 —
Ubuntu 22.04 LTS linux-gcp 5.15.0-1092.101 USN-7774-1
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 5.15.0-1089.95 USN-7774-1
Ubuntu 22.04 LTS linux-gkeop 5.15.0-1075.83 USN-7774-1
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 5.15.0-1086.89 USN-7774-1
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 5.15.0-1087.93 USN-7774-1
Ubuntu 22.04 LTS linux-kvm 5.15.0-1088.93 USN-7774-4
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 5.15.0-1087.88 USN-7774-1
Ubuntu 22.04 LTS linux-nvidia-tegra 5.15.0-1045.45 USN-7774-1
Ubuntu 22.04 LTS linux-nvidia-tegra-igx 5.15.0-1034.34 USN-7774-5
Ubuntu 22.04 LTS linux-oracle 5.15.0-1090.96 USN-7774-1
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 5.15.0-1056.60 USN-7774-1
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 6.14.0-1012.12~24.04.1 USN-7769-2
Ubuntu Pro Realtime 22.04 LTS linux-intel-iot-realtime 5.15.0-1085.87 USN-7774-3
Ubuntu Pro Realtime 22.04 LTS linux-realtime 5.15.0-1092.101 USN-7774-3
Ubuntu Pro Realtime 22.04 LTS linux-realtime-6.8 6.8.1-1041.42~22.04.1 USN-8028-2
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 5.15.0-1092.99+fips1 USN-7774-2
Ubuntu Pro FIPS-updates 22.04 LTS linux-azure-fips 5.15.0-1096.105+fips1 USN-7775-1
Ubuntu Pro FIPS-updates 22.04 LTS linux-fips 5.15.0-156.166+fips1 USN-7774-2
Ubuntu Pro FIPS-updates 22.04 LTS linux-gcp-fips 5.15.0-1092.101+fips1 USN-7774-2
Ubuntu Pro FIPS-preview 22.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro 20.04 LTS linux-aws-5.15 5.15.0-1092.99~20.04.1 USN-7774-1
Ubuntu Pro 20.04 LTS linux-azure-5.15 5.15.0-1096.105~20.04.1 USN-7775-3
Ubuntu Pro 20.04 LTS linux-gcp-5.15 5.15.0-1092.101~20.04.1 USN-7774-1
Ubuntu Pro 20.04 LTS linux-hwe-5.15 +1 5.15.0-156.166~20.04.1 USN-7774-1
Ubuntu Pro 20.04 LTS linux-ibm-5.15 5.15.0-1086.89~20.04.1 USN-7774-1
Ubuntu Pro 20.04 LTS linux-intel-iotg-5.15 5.15.0-1087.93~20.04.1 USN-7774-1
Ubuntu Pro 20.04 LTS linux-nvidia-tegra-5.15 5.15.0-1045.45~20.04.1 USN-7774-1
Ubuntu Pro 20.04 LTS linux-oracle-5.15 5.15.0-1090.96~20.04.1 USN-7776-1
Ubuntu Pro 20.04 LTS linux-riscv-5.15 5.15.0-1087.91~20.04.1 —
ReleasePackageFixed inAdvisory
SLES 15 SP7 kernel-64kb +5 6.4.0-150700.53.11.1 SUSE-SU-2025:02997-1
SLES 15 SP7 kernel-azure +2 6.4.0-150700.20.11.1 SUSE-SU-2025:03011-1
SLES 15 SP7 kernel-default-base 6.4.0-150700.53.11.1.150700.17.9.4 SUSE-SU-2025:02997-1
SLES 15 SP7 kernel-docs 6.4.0-150700.53.11.3 SUSE-SU-2025:02997-1
SLES 15 SP6 kernel-64kb +6 6.4.0-150600.23.65.1 SUSE-SU-2025:02996-1
SLES 15 SP6 kernel-azure +2 6.4.0-150600.8.48.1 SUSE-SU-2025:02969-1
SLES 15 SP6 kernel-coco +3 6.4.0-15061.28.coco15sp6.1 SUSE-SU-2025:02923-1
SLES 15 SP6 kernel-default-base 6.4.0-150600.23.65.1.150600.12.28.4 SUSE-SU-2025:02996-1
Show 6 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLE Micro 6.1 kernel-default-base 6.4.0-32.1.21.10 SUSE-SU-2025:20602-1
SLE Micro 6.1 kernel-rt +1 6.4.0-35.1 SUSE-SU-2025:20601-1
SLE Micro 6.1 kernel-source +2 6.4.0-32.1 SUSE-SU-2025:20602-1
SLE Micro 6.0 kernel-default-base 6.4.0-32.1.21.10 SUSE-SU-2025:20586-1
SLE Micro 6.0 kernel-rt +1 6.4.0-35.1 SUSE-SU-2025:20577-1
SLE Micro 6.0 kernel-source +2 6.4.0-32.1 SUSE-SU-2025:20586-1
SLE Live Patching 15 SP7 kernel-default 6.4.0-150700.53.11.1 SUSE-SU-2025:02997-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7-RT_Update_3 1-150700.1.5.1 SUSE-SU-2025:02853-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7_Update_3 1-150700.15.3.4 SUSE-SU-2025:02997-1
SLE Live Patching 15 SP6 kernel-default 6.4.0-150600.23.65.1 SUSE-SU-2025:02996-1
SLE Live Patching 15 SP6 kernel-livepatch-SLE15-SP6-RT_Update_14 1-150600.1.5.1 SUSE-SU-2025:03023-1
SLE Live Patching 15 SP6 kernel-livepatch-SLE15-SP6_Update_14 1-150600.13.3.4 SUSE-SU-2025:02996-1
SUSE Real Time Module 15 SP7 kernel-rt +2 6.4.0-150700.7.13.1 SUSE-SU-2025:02853-1
SUSE Real Time Module 15 SP6 kernel-rt +3 6.4.0-150600.10.49.1 SUSE-SU-2025:03023-1
ReleasePackageFixed inAdvisory
openSUSE Leap 15.6 dtb-aarch64 +10 6.4.0-150600.23.65.1 SUSE-SU-2025:02996-1
openSUSE Leap 15.6 kernel-azure +2 6.4.0-150600.8.48.1 SUSE-SU-2025:02969-1
openSUSE Leap 15.6 kernel-default-base 6.4.0-150600.23.65.1.150600.12.28.4 SUSE-SU-2025:02996-1
openSUSE Leap 15.6 kernel-rt +3 6.4.0-150600.10.49.1 SUSE-SU-2025:03023-1

Amazon Linux

ReleasePackageFixed inAdvisory
Amazon Linux 2023 bpftool +14 6.12.35-55.103.amzn2023 ALAS2023-2025-1080
Amazon Linux 2023 kernel-livepatch-6.12.35-55.103 1.0-0.amzn2023 ALAS2023-2025-1080

Azure Linux

ReleasePackageFixed inAdvisory
Azure Linux 3 kernel 6.6.96.1-1 —

Oracle Linux

ReleasePackageFixed inAdvisory
Oracle Linux 9 kernel-uek +34 6.12.0-103.40.4.1.el10uek ELSA-2025-20551
Oracle Linux 8 bpftool +18 5.15.0-312.187.5.el9uek ELSA-2025-20552

Advisories 50

References