# CVE-2025-40201: kernel/sys.c: fix the racy usage of task_lock(tsk->group_leader) in sys_prlimit64() paths

CVE-2025-40201 is fixed in 60 products on 1 platform, first by DEBIAN-CVE-2025-40201, released November 12, 2025. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2025-40201
- Priority: High
- CVSS: 7.8 (Important)
- EPSS: 0.0015
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Nov 12, 2025
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-40201

## Description

In the Linux kernel, the following vulnerability has been resolved:  kernel/sys.c: fix the racy usage of task_lock(tsk->group_leader) in sys_prlimit64() paths  The usage of task_lock(tsk->group_leader) in sys_prlimit64()->do_prlimit() path is very broken.  sys_prlimit64() does get_task_struct(tsk) but this only protects task_struct itself. If tsk != current and tsk is not a leader, this process can exit/exec and task_lock(tsk->group_leader) may use the already freed task_struct.  Another problem is that sys_prlimit64() can race with mt-exec which changes ->group_leader. In this case do_prlimit() may take the wrong lock, or (worse) ->group_leader may change between task_lock() and task_unlock().  Change sys_prlimit64() to take tasklist_lock when necessary. This is not nice, but I don't see a better fix for -stable.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | bpftool amzn 2023 | 1:6.1.158-178.288.amzn2023 | [ALAS2023-2025-1297](https://patchblox.com/security/data/fix/linux/alas2023-2025-1297.md) | Dec 8, 2025 |
| Linux | bpftool-debuginfo amzn 2023 | 1:6.1.158-178.288.amzn2023 | [ALAS2023-2025-1297](https://patchblox.com/security/data/fix/linux/alas2023-2025-1297.md) | Dec 8, 2025 |
| Linux | bpftool6.12 amzn 2023 | 1:6.12.55-74.119.amzn2023 | [ALAS2023-2025-1316](https://patchblox.com/security/data/fix/linux/alas2023-2025-1316.md) | Dec 8, 2025 |
| Linux | bpftool6.12-debuginfo amzn 2023 | 1:6.12.55-74.119.amzn2023 | [ALAS2023-2025-1316](https://patchblox.com/security/data/fix/linux/alas2023-2025-1316.md) | Dec 8, 2025 |
| Linux | dtb-aarch64 opensuse-leap 16.0 | 6.12.0-160000.8.1 | [OPENSUSE-SU-2025:20172-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20172-1.md) | Dec 19, 2025 |
| Linux | kernel amzn 2023 | 1:6.1.158-178.288.amzn2023 | [ALAS2023-2025-1297](https://patchblox.com/security/data/fix/linux/alas2023-2025-1297.md) | Dec 8, 2025 |
| Linux | kernel-64kb opensuse-leap 16.0 | 6.12.0-160000.8.1 | [OPENSUSE-SU-2025:20172-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20172-1.md) | Dec 19, 2025 |
| Linux | kernel-64kb sles 15.7 | 6.4.0-150700.53.34.1 | [SUSE-SU-2026:1081-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-1081-1.md) | Mar 26, 2026 |
| Linux | kernel-64kb sles 16.0 | 6.12.0-160000.8.1 | [SUSE-SU-2026:20015-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-20015-1.md) | Dec 19, 2025 |
| Linux | kernel-azure sles 15.7 | 6.4.0-150700.53.34.1 | [SUSE-SU-2026:1081-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-1081-1.md) | Mar 26, 2026 |
| Linux | kernel-debuginfo amzn 2023 | 1:6.1.158-178.288.amzn2023 | [ALAS2023-2025-1297](https://patchblox.com/security/data/fix/linux/alas2023-2025-1297.md) | Dec 8, 2025 |
| Linux | kernel-debuginfo-common-aarch64 amzn 2023 | 1:6.1.158-178.288.amzn2023 | [ALAS2023-2025-1297](https://patchblox.com/security/data/fix/linux/alas2023-2025-1297.md) | Dec 8, 2025 |
| Linux | kernel-debuginfo-common-x86_64 amzn 2023 | 1:6.1.158-178.288.amzn2023 | [ALAS2023-2025-1297](https://patchblox.com/security/data/fix/linux/alas2023-2025-1297.md) | Dec 8, 2025 |
| Linux | kernel-default opensuse-leap 16.0 | 6.12.0-160000.8.1 | [OPENSUSE-SU-2025:20172-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20172-1.md) | Dec 19, 2025 |
| Linux | kernel-default sles 15.7 | 6.4.0-150700.53.34.1 | [SUSE-SU-2026:1081-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-1081-1.md) | Mar 26, 2026 |
| Linux | kernel-default sles 16.0 | 6.12.0-160000.8.1 | [SUSE-SU-2026:20015-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-20015-1.md) | Dec 19, 2025 |
| Linux | kernel-default-base opensuse-leap 16.0 | 6.12.0-160000.8.1.160000.2.5 | [OPENSUSE-SU-2025:20172-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20172-1.md) | Dec 19, 2025 |
| Linux | kernel-default-base sles 15.7 | 6.4.0-150700.53.34.1.150700.17.23.1 | [SUSE-SU-2026:1081-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-1081-1.md) | Mar 26, 2026 |
| Linux | kernel-default-base sles 16.0 | 6.12.0-160000.8.1.160000.2.5 | [SUSE-SU-2026:20015-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-20015-1.md) | Dec 19, 2025 |
| Linux | kernel-devel amzn 2023 | 1:6.1.158-178.288.amzn2023 | [ALAS2023-2025-1297](https://patchblox.com/security/data/fix/linux/alas2023-2025-1297.md) | Dec 8, 2025 |
| Linux | kernel-docs opensuse-leap 16.0 | 6.12.0-160000.8.1 | [OPENSUSE-SU-2025:20172-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20172-1.md) | Dec 19, 2025 |
| Linux | kernel-docs sles 15.7 | 6.4.0-150700.53.34.1 | [SUSE-SU-2026:1081-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-1081-1.md) | Mar 26, 2026 |
| Linux | kernel-docs sles 16.0 | 6.12.0-160000.8.1 | [SUSE-SU-2026:20015-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-20015-1.md) | Dec 19, 2025 |
| Linux | kernel-headers amzn 2023 | 1:6.1.158-178.288.amzn2023 | [ALAS2023-2025-1297](https://patchblox.com/security/data/fix/linux/alas2023-2025-1297.md) | Dec 8, 2025 |
| Linux | kernel-kvmsmall opensuse-leap 16.0 | 6.12.0-160000.8.1 | [OPENSUSE-SU-2025:20172-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20172-1.md) | Dec 19, 2025 |
| Linux | kernel-kvmsmall sles 16.0 | 6.12.0-160000.8.1 | [SUSE-SU-2026:20015-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-20015-1.md) | Dec 19, 2025 |
| Linux | kernel-libbpf amzn 2023 | 1:6.1.158-178.288.amzn2023 | [ALAS2023-2025-1297](https://patchblox.com/security/data/fix/linux/alas2023-2025-1297.md) | Dec 8, 2025 |
| Linux | kernel-libbpf-debuginfo amzn 2023 | 1:6.1.158-178.288.amzn2023 | [ALAS2023-2025-1297](https://patchblox.com/security/data/fix/linux/alas2023-2025-1297.md) | Dec 8, 2025 |
| Linux | kernel-libbpf-devel amzn 2023 | 1:6.1.158-178.288.amzn2023 | [ALAS2023-2025-1297](https://patchblox.com/security/data/fix/linux/alas2023-2025-1297.md) | Dec 8, 2025 |
| Linux | kernel-libbpf-static amzn 2023 | 1:6.1.158-178.288.amzn2023 | [ALAS2023-2025-1297](https://patchblox.com/security/data/fix/linux/alas2023-2025-1297.md) | Dec 8, 2025 |
| Linux | kernel-livepatch-6.1.158-178.288 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2025-1297](https://patchblox.com/security/data/fix/linux/alas2023-2025-1297.md) | Dec 8, 2025 |
| Linux | kernel-livepatch-6.12.55-74.119 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2025-1316](https://patchblox.com/security/data/fix/linux/alas2023-2025-1316.md) | Dec 8, 2025 |
| Linux | kernel-livepatch-SLE15-SP7-RT_Update_10 sles 15.7 | 1-150700.1.3.1 | [SUSE-SU-2026:0962-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-0962-1.md) | Mar 23, 2026 |
| Linux | kernel-livepatch-SLE15-SP7_Update_10 sles 15.7 | 1-150700.15.3.1 | [SUSE-SU-2026:1081-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-1081-1.md) | Mar 26, 2026 |
| Linux | kernel-modules-extra amzn 2023 | 1:6.1.158-178.288.amzn2023 | [ALAS2023-2025-1297](https://patchblox.com/security/data/fix/linux/alas2023-2025-1297.md) | Dec 8, 2025 |
| Linux | kernel-modules-extra-common amzn 2023 | 1:6.1.158-178.288.amzn2023 | [ALAS2023-2025-1297](https://patchblox.com/security/data/fix/linux/alas2023-2025-1297.md) | Dec 8, 2025 |
| Linux | kernel-obs-build opensuse-leap 16.0 | 6.12.0-160000.8.1 | [OPENSUSE-SU-2025:20172-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20172-1.md) | Dec 19, 2025 |
| Linux | kernel-obs-build sles 15.7 | 6.4.0-150700.53.34.1 | [SUSE-SU-2026:1081-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-1081-1.md) | Mar 26, 2026 |
| Linux | kernel-obs-qa opensuse-leap 16.0 | 6.12.0-160000.8.1 | [OPENSUSE-SU-2025:20172-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20172-1.md) | Dec 19, 2025 |
| Linux | kernel-obs-qa sles 16.0 | 6.12.0-160000.8.1 | [SUSE-SU-2026:20015-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-20015-1.md) | Dec 19, 2025 |
| Linux | kernel-rt opensuse-leap 16.0 | 6.12.0-160000.8.1 | [OPENSUSE-SU-2025:20172-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20172-1.md) | Dec 19, 2025 |
| Linux | kernel-source opensuse-leap 16.0 | 6.12.0-160000.8.1 | [OPENSUSE-SU-2025:20172-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20172-1.md) | Dec 19, 2025 |
| Linux | kernel-source sles 15.7 | 6.4.0-150700.53.34.1 | [SUSE-SU-2026:1081-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-1081-1.md) | Mar 26, 2026 |
| Linux | kernel-source sles 16.0 | 6.12.0-160000.8.1 | [SUSE-SU-2026:20015-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-20015-1.md) | Dec 19, 2025 |
| Linux | kernel-syms opensuse-leap 16.0 | 6.12.0-160000.8.1 | [OPENSUSE-SU-2025:20172-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20172-1.md) | Dec 19, 2025 |
| Linux | kernel-syms sles 15.7 | 6.4.0-150700.53.34.1 | [SUSE-SU-2026:1081-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-1081-1.md) | Mar 26, 2026 |
| Linux | kernel-syms sles 16.0 | 6.12.0-160000.8.1 | [SUSE-SU-2026:20015-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-20015-1.md) | Dec 19, 2025 |
| Linux | kernel-tools amzn 2023 | 1:6.1.158-178.288.amzn2023 | [ALAS2023-2025-1297](https://patchblox.com/security/data/fix/linux/alas2023-2025-1297.md) | Dec 8, 2025 |
| Linux | kernel-tools-debuginfo amzn 2023 | 1:6.1.158-178.288.amzn2023 | [ALAS2023-2025-1297](https://patchblox.com/security/data/fix/linux/alas2023-2025-1297.md) | Dec 8, 2025 |
| Linux | kernel-tools-devel amzn 2023 | 1:6.1.158-178.288.amzn2023 | [ALAS2023-2025-1297](https://patchblox.com/security/data/fix/linux/alas2023-2025-1297.md) | Dec 8, 2025 |
| Linux | kernel-zfcpdump opensuse-leap 16.0 | 6.12.0-160000.8.1 | [OPENSUSE-SU-2025:20172-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20172-1.md) | Dec 19, 2025 |
| Linux | kernel-zfcpdump sles 15.7 | 6.4.0-150700.53.34.1 | [SUSE-SU-2026:1081-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-1081-1.md) | Mar 26, 2026 |
| Linux | kernel-zfcpdump sles 16.0 | 6.12.0-160000.8.1 | [SUSE-SU-2026:20015-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-20015-1.md) | Dec 19, 2025 |
| Linux | kernel6.12 amzn 2023 | 1:6.12.55-74.119.amzn2023 | [ALAS2023-2025-1316](https://patchblox.com/security/data/fix/linux/alas2023-2025-1316.md) | Dec 8, 2025 |
| Linux | kernel6.12-debuginfo amzn 2023 | 1:6.12.55-74.119.amzn2023 | [ALAS2023-2025-1316](https://patchblox.com/security/data/fix/linux/alas2023-2025-1316.md) | Dec 8, 2025 |
| Linux | kernel6.12-debuginfo-common-aarch64 amzn 2023 | 1:6.12.55-74.119.amzn2023 | [ALAS2023-2025-1316](https://patchblox.com/security/data/fix/linux/alas2023-2025-1316.md) | Dec 8, 2025 |
| Linux | kernel6.12-debuginfo-common-x86_64 amzn 2023 | 1:6.12.55-74.119.amzn2023 | [ALAS2023-2025-1316](https://patchblox.com/security/data/fix/linux/alas2023-2025-1316.md) | Dec 8, 2025 |
| Linux | kernel6.12-devel amzn 2023 | 1:6.12.55-74.119.amzn2023 | [ALAS2023-2025-1316](https://patchblox.com/security/data/fix/linux/alas2023-2025-1316.md) | Dec 8, 2025 |
| Linux | kernel6.12-headers amzn 2023 | 1:6.12.55-74.119.amzn2023 | [ALAS2023-2025-1316](https://patchblox.com/security/data/fix/linux/alas2023-2025-1316.md) | Dec 8, 2025 |
| Linux | kernel6.12-libbpf amzn 2023 | 1:6.12.55-74.119.amzn2023 | [ALAS2023-2025-1316](https://patchblox.com/security/data/fix/linux/alas2023-2025-1316.md) | Dec 8, 2025 |
| Linux | kernel6.12-libbpf-debuginfo amzn 2023 | 1:6.12.55-74.119.amzn2023 | [ALAS2023-2025-1316](https://patchblox.com/security/data/fix/linux/alas2023-2025-1316.md) | Dec 8, 2025 |
| Linux | kernel6.12-libbpf-devel amzn 2023 | 1:6.12.55-74.119.amzn2023 | [ALAS2023-2025-1316](https://patchblox.com/security/data/fix/linux/alas2023-2025-1316.md) | Dec 8, 2025 |
| Linux | kernel6.12-libbpf-static amzn 2023 | 1:6.12.55-74.119.amzn2023 | [ALAS2023-2025-1316](https://patchblox.com/security/data/fix/linux/alas2023-2025-1316.md) | Dec 8, 2025 |
| Linux | kernel6.12-modules-extra amzn 2023 | 1:6.12.55-74.119.amzn2023 | [ALAS2023-2025-1316](https://patchblox.com/security/data/fix/linux/alas2023-2025-1316.md) | Dec 8, 2025 |
| Linux | kernel6.12-modules-extra-common amzn 2023 | 1:6.12.55-74.119.amzn2023 | [ALAS2023-2025-1316](https://patchblox.com/security/data/fix/linux/alas2023-2025-1316.md) | Dec 8, 2025 |
| Linux | kernel6.12-tools amzn 2023 | 1:6.12.55-74.119.amzn2023 | [ALAS2023-2025-1316](https://patchblox.com/security/data/fix/linux/alas2023-2025-1316.md) | Dec 8, 2025 |
| Linux | kernel6.12-tools-debuginfo amzn 2023 | 1:6.12.55-74.119.amzn2023 | [ALAS2023-2025-1316](https://patchblox.com/security/data/fix/linux/alas2023-2025-1316.md) | Dec 8, 2025 |
| Linux | kernel6.12-tools-devel amzn 2023 | 1:6.12.55-74.119.amzn2023 | [ALAS2023-2025-1316](https://patchblox.com/security/data/fix/linux/alas2023-2025-1316.md) | Dec 8, 2025 |
| Linux | linux Debian 12.15 (bookworm) | 6.1.158-1 | [DEBIAN-CVE-2025-40201](https://patchblox.com/security/data/fix/linux/debian-cve-2025-40201.md) | Nov 12, 2025 |
| Linux | linux Debian 13.5 (trixie) | 6.12.57-1 | [DEBIAN-CVE-2025-40201](https://patchblox.com/security/data/fix/linux/debian-cve-2025-40201.md) | Nov 12, 2025 |
| Linux | linux Debian 14 | 6.17.6-1 | [DEBIAN-CVE-2025-40201](https://patchblox.com/security/data/fix/linux/debian-cve-2025-40201.md) | Nov 12, 2025 |
| Linux | perf amzn 2023 | 1:6.1.158-178.288.amzn2023 | [ALAS2023-2025-1297](https://patchblox.com/security/data/fix/linux/alas2023-2025-1297.md) | Dec 8, 2025 |
| Linux | perf-debuginfo amzn 2023 | 1:6.1.158-178.288.amzn2023 | [ALAS2023-2025-1297](https://patchblox.com/security/data/fix/linux/alas2023-2025-1297.md) | Dec 8, 2025 |
| Linux | perf6.12 amzn 2023 | 1:6.12.55-74.119.amzn2023 | [ALAS2023-2025-1316](https://patchblox.com/security/data/fix/linux/alas2023-2025-1316.md) | Dec 8, 2025 |
| Linux | perf6.12-debuginfo amzn 2023 | 1:6.12.55-74.119.amzn2023 | [ALAS2023-2025-1316](https://patchblox.com/security/data/fix/linux/alas2023-2025-1316.md) | Dec 8, 2025 |
| Linux | python3-perf amzn 2023 | 1:6.1.158-178.288.amzn2023 | [ALAS2023-2025-1297](https://patchblox.com/security/data/fix/linux/alas2023-2025-1297.md) | Dec 8, 2025 |
| Linux | python3-perf-debuginfo amzn 2023 | 1:6.1.158-178.288.amzn2023 | [ALAS2023-2025-1297](https://patchblox.com/security/data/fix/linux/alas2023-2025-1297.md) | Dec 8, 2025 |
| Linux | python3-perf6.12 amzn 2023 | 1:6.12.55-74.119.amzn2023 | [ALAS2023-2025-1316](https://patchblox.com/security/data/fix/linux/alas2023-2025-1316.md) | Dec 8, 2025 |
| Linux | python3-perf6.12-debuginfo amzn 2023 | 1:6.12.55-74.119.amzn2023 | [ALAS2023-2025-1316](https://patchblox.com/security/data/fix/linux/alas2023-2025-1316.md) | Dec 8, 2025 |

---

Data as of 2026-11-08T00:53:09Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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