# CVE-2025-38628: vdpa/mlx5: Fix release of uninitialized resources on error path > A null pointer dereference in the Linux kernel's mlx5 vdpa driver causes a system crash when adding a device without a MAC address. - **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** 22 Aug 2025 - **Updated:** 11 May 2026 - **Also known as:** BELL-CVE-2025-38628, DEBIAN-CVE-2025-38628, GHSA-2qfm-24x8-gwfp, ROOT-OS-DEBIAN-13-CVE-2025-38628, UBUNTU-CVE-2025-38628 ## What is CVE-2025-38628? CVE-2025-38628 is a medium-severity vulnerability in Linux kernel, published on 22 Aug 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: vdpa/mlx5: Fix release of uninitialized resources on error path The commit in the fixes tag made sure that mlx5_vdpa_free() is the single entrypoint for removing the vdpa device resources added in mlx5_vdpa_dev_add(), even in the cleanup path of mlx5_vdpa_dev_add(). This means that all functions from mlx5_vdpa_free() should be able to handle uninitialized resources. This was not the case though: mlx5_vdpa_destroy_mr_resources() and mlx5_cmd_cleanup_async_ctx() were not able to do so. This caused the splat below when adding a vdpa device without a MAC address. This patch fixes these remaining issues: - Makes mlx5_vdpa_destroy_mr_resources() return early if called on uninitialized resources. - Moves mlx5_cmd_init_async_ctx() early on during device addition because it can't fail. This means that mlx5_cmd_cleanup_async_ctx() also can't fail. To mirror this, move the call site of mlx5_cmd_cleanup_async_ctx() in mlx5_vdpa_free(). An additional comment was added in mlx5_vdpa_free() to document the expectations of functions called from this context. Splat: mlx5_core 0000:b5:03.2: mlx5_vdpa_dev_add:3950:(pid 2306) warning: No mac address provisioned? ------------[ cut here ]------------ WARNING: CPU: 13 PID: 2306 at kernel/workqueue.c:4207 __flush_work+0x9a/0xb0 [...] Call Trace: ? __try_to_del_timer_sync+0x61/0x90 ? __timer_delete_sync+0x2b/0x40 mlx5_vdpa_destroy_mr_resources+0x1c/0x40 [mlx5_vdpa] mlx5_vdpa_free+0x45/0x160 [mlx5_vdpa] vdpa_release_dev+0x1e/0x50 [vdpa] device_release+0x31/0x90 kobject_cleanup+0x37/0x130 mlx5_vdpa_dev_add+0x327/0x890 [mlx5_vdpa] vdpa_nl_cmd_dev_add_set_doit+0x2c1/0x4d0 [vdpa] genl_family_rcv_msg_doit+0xd8/0x130 genl_family_rcv_msg+0x14b/0x220 ? __pfx_vdpa_nl_cmd_dev_add_set_doit+0x10/0x10 [vdpa] genl_rcv_msg+0x47/0xa0 ? __pfx_genl_rcv_msg+0x10/0x10 netlink_rcv_skb+0x53/0x100 genl_rcv+0x24/0x40 netlink_unicast+0x27b/0x3b0 netlink_sendmsg+0x1f7/0x430 __sys_sendto+0x1fa/0x210 ? ___pte_offset_map+0x17/0x160 ? next_uptodate_folio+0x85/0x2b0 ? percpu_counter_add_batch+0x51/0x90 ? filemap_map_pages+0x515/0x660 __x64_sys_sendto+0x20/0x30 do_syscall_64+0x7b/0x2c0 ? do_read_fault+0x108/0x220 ? do_pte_missing+0x14a/0x3e0 ? __handle_mm_fault+0x321/0x730 ? count_memcg_events+0x13f/0x180 ? handle_mm_fault+0x1fb/0x2d0 ? do_user_addr_fault+0x20c/0x700 ? syscall_exit_work+0x104/0x140 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f0c25b0feca [...] ---[ end trace 0000000000000000 ]--- Weakness: CWE-908 (Use of Uninitialized Resource) ## Which versions are affected by CVE-2025-38628? It affects 1 product. Products: Linux kernel. ## How do I fix CVE-2025-38628? Apply the vendor's patch. ## Is CVE-2025-38628 being exploited? There is no known exploitation of CVE-2025-38628 in the wild and no public exploit code. ## Other vulnerabilities in Linux kernel - [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild) - [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild) - [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild) - [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild) - [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2025-38628 and fix it if it is affected. What it is: CVE-2025-38628 is a medium-severity vulnerability in Linux kernel, published on 22 Aug 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-2025-38628 in the wild and no public exploit code. Affected product: Linux kernel. 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-2025-38628/ (Markdown: https://insights.sbomify.com/CVE-2025-38628/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2025-38628 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-38628 - OSV: https://osv.dev/vulnerability/CVE-2025-38628 --- From sbomify Insights: https://insights.sbomify.com/CVE-2025-38628/ Summaries are generated and may contain mistakes; the official description above is the record.