# CVE-2025-38477: net/sched: sch_qfq: Fix race condition on qfq_aggregate > A race condition in the Linux kernel's QFQ scheduler allows attackers to trigger use-after-free or NULL dereference, potentially causing crashes or code execution. - **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Local or same network only - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 28 Jul 2025 - **Updated:** 15 Oct 2026 - **Also known as:** AZL-65907, AZL-73046, BELL-CVE-2025-38477, DEBIAN-CVE-2025-38477, GHSA-79vc-v8qm-8x53, OESA-2025-2057, ROOT-OS-DEBIAN-11-CVE-2025-38477, ROOT-OS-DEBIAN-12-CVE-2025-38477, ROOT-OS-UBUNTU-2204-CVE-2025-38477, ROOT-OS-UBUNTU-2404-CVE-2025-38477, SUSE-SU-2025:03473-1, SUSE-SU-2025:03479-1, SUSE-SU-2025:03485-1, SUSE-SU-2025:03497-1, SUSE-SU-2025:03550-1, SUSE-SU-2025:03552-1, SUSE-SU-2025:03562-1, SUSE-SU-2025:03568-1, SUSE-SU-2025:03576-1, SUSE-SU-2025:03583-1, SUSE-SU-2025:20812-1, SUSE-SU-2025:20820-1, SUSE-SU-2025:20839-1, SUSE-SU-2025:20842-1, UBUNTU-CVE-2025-38477 ## What is CVE-2025-38477? CVE-2025-38477 is a high-severity vulnerability in Debian Debian Linux, published on 28 Jul 2025. It can only be exploited from the same machine or local network, with no action from the victim. ### Official description In the Linux kernel, the following vulnerability has been resolved: net/sched: sch_qfq: Fix race condition on qfq_aggregate A race condition can occur when 'agg' is modified in qfq_change_agg (called during qfq_enqueue) while other threads access it concurrently. For example, qfq_dump_class may trigger a NULL dereference, and qfq_delete_class may cause a use-after-free. This patch addresses the issue by: 1. Moved qfq_destroy_class into the critical section. 2. Added sch_tree_lock protection to qfq_dump_class and qfq_dump_class_stats. Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization) ## Which versions are affected by CVE-2025-38477? It affects 2 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `kgraft-patch-SLE12-SP5_Update_69` | SUSE:Linux Enterprise Live Patching 12 SP5 | All versions | 5-2.1 | | `kgraft-patch-SLE12-SP5_Update_70` | SUSE:Linux Enterprise Live Patching 12 SP5 | All versions | 5-2.1 | | `kernel-livepatch-SLE15-SP3_Update_58` | SUSE:Linux Enterprise Live Patching 15 SP3 | All versions | 6-150300.2.1 | | `kernel-livepatch-SLE15-SP4_Update_41` | SUSE:Linux Enterprise Live Patching 15 SP4 | All versions | 6-150400.2.1 | | `kernel-livepatch-SLE15-SP4_Update_42` | SUSE:Linux Enterprise Live Patching 15 SP4 | All versions | 5-150400.2.1 | | `kernel-livepatch-SLE15-SP5_Update_29` | SUSE:Linux Enterprise Live Patching 15 SP5 | All versions | 4-150500.2.1 | | `kernel-livepatch-SLE15-SP6-RT_Update_13` | SUSE:Linux Enterprise Live Patching 15 SP6 | All versions | 5-150600.2.1 | | `kernel-livepatch-SLE15-SP6_Update_13` | SUSE:Linux Enterprise Live Patching 15 SP6 | All versions | 5-150600.2.1 | | `kernel-livepatch-SLE15-SP7-RT_Update_2` | SUSE:Linux Enterprise Live Patching 15 SP7 | All versions | 5-150700.2.1 | | `kernel-livepatch-SLE15-SP7_Update_2` | SUSE:Linux Enterprise Live Patching 15 SP7 | All versions | 5-150700.2.1 | | `kernel-livepatch-MICRO-6-0-RT_Update_10` | SUSE:Linux Micro 6.0 | All versions | 5-1.1 | | `kernel-livepatch-MICRO-6-0_Update_9` | SUSE:Linux Micro 6.0 | All versions | 6-1.2 | | `kernel-livepatch-MICRO-6-0-RT_Update_10` | SUSE:Linux Micro 6.1 | All versions | 5-1.1 | | `kernel-livepatch-MICRO-6-0_Update_9` | SUSE:Linux Micro 6.1 | All versions | 6-1.2 | Products: Debian Debian Linux, Linux kernel. ## How do I fix CVE-2025-38477? Apply the vendor's patch. ## Is CVE-2025-38477 being exploited? There is no known exploitation of CVE-2025-38477 in the wild and no public exploit code. ## Other vulnerabilities in Debian Debian Linux - [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild) - [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild) - [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild) - [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild) - [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2025-38477 and fix it if it is affected. What it is: CVE-2025-38477 is a high-severity vulnerability in Debian Debian Linux, published on 28 Jul 2025. It can only be exploited from the same machine or local network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2025-38477 in the wild and no public exploit code. Affected product: Debian Debian Linux. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2025-38477/ (Markdown: https://insights.sbomify.com/CVE-2025-38477/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2025-38477 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-38477 - OSV: https://osv.dev/vulnerability/CVE-2025-38477 --- From sbomify Insights: https://insights.sbomify.com/CVE-2025-38477/ Summaries are generated and may contain mistakes; the official description above is the record.