# CVE-2024-38664: drm: zynqmp_dpsub: Always register bridge > A missing initialization in the ZynqMP display subsystem driver causes a kernel warning and potential crash when handling hotplug events. - **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:** 24 Jun 2024 - **Updated:** 11 May 2026 - **Also known as:** AZL-42895, AZL-42919, BELL-CVE-2024-38664, DEBIAN-CVE-2024-38664, GHSA-rj28-pp8g-vc2r, UBUNTU-CVE-2024-38664 ## What is CVE-2024-38664? CVE-2024-38664 is a high-severity vulnerability in Linux kernel, published on 24 Jun 2024. 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: drm: zynqmp_dpsub: Always register bridge We must always register the DRM bridge, since zynqmp_dp_hpd_work_func calls drm_bridge_hpd_notify, which in turn expects hpd_mutex to be initialized. We do this before zynqmp_dpsub_drm_init since that calls drm_bridge_attach. This fixes the following lockdep warning: [ 19.217084] ------------[ cut here ]------------ [ 19.227530] DEBUG_LOCKS_WARN_ON(lock->magic != lock) [ 19.227768] WARNING: CPU: 0 PID: 140 at kernel/locking/mutex.c:582 __mutex_lock+0x4bc/0x550 [ 19.241696] Modules linked in: [ 19.244937] CPU: 0 PID: 140 Comm: kworker/0:4 Not tainted 6.6.20+ #96 [ 19.252046] Hardware name: xlnx,zynqmp (DT) [ 19.256421] Workqueue: events zynqmp_dp_hpd_work_func [ 19.261795] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 19.269104] pc : __mutex_lock+0x4bc/0x550 [ 19.273364] lr : __mutex_lock+0x4bc/0x550 [ 19.277592] sp : ffffffc085c5bbe0 [ 19.281066] x29: ffffffc085c5bbe0 x28: 0000000000000000 x27: ffffff88009417f8 [ 19.288624] x26: ffffff8800941788 x25: ffffff8800020008 x24: ffffffc082aa3000 [ 19.296227] x23: ffffffc080d90e3c x22: 0000000000000002 x21: 0000000000000000 [ 19.303744] x20: 0000000000000000 x19: ffffff88002f5210 x18: 0000000000000000 [ 19.311295] x17: 6c707369642e3030 x16: 3030613464662072 x15: 0720072007200720 [ 19.318922] x14: 0000000000000000 x13: 284e4f5f4e524157 x12: 0000000000000001 [ 19.326442] x11: 0001ffc085c5b940 x10: 0001ff88003f388b x9 : 0001ff88003f3888 [ 19.334003] x8 : 0001ff88003f3888 x7 : 0000000000000000 x6 : 0000000000000000 [ 19.341537] x5 : 0000000000000000 x4 : 0000000000001668 x3 : 0000000000000000 [ 19.349054] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffffff88003f3880 [ 19.356581] Call trace: [ 19.359160] __mutex_lock+0x4bc/0x550 [ 19.363032] mutex_lock_nested+0x24/0x30 [ 19.367187] drm_bridge_hpd_notify+0x2c/0x6c [ 19.371698] zynqmp_dp_hpd_work_func+0x44/0x54 [ 19.376364] process_one_work+0x3ac/0x988 [ 19.380660] worker_thread+0x398/0x694 [ 19.384736] kthread+0x1bc/0x1c0 [ 19.388241] ret_from_fork+0x10/0x20 [ 19.392031] irq event stamp: 183 [ 19.395450] hardirqs last enabled at (183): [] finish_task_switch.isra.0+0xa8/0x2d4 [ 19.405140] hardirqs last disabled at (182): [] __schedule+0x714/0xd04 [ 19.413612] softirqs last enabled at (114): [] srcu_invoke_callbacks+0x158/0x23c [ 19.423128] softirqs last disabled at (110): [] srcu_invoke_callbacks+0x158/0x23c [ 19.432614] ---[ end trace 0000000000000000 ]--- (cherry picked from commit 61ba791c4a7a09a370c45b70a81b8c7d4cf6b2ae) Weakness: CWE-667 (Improper Locking) ## Which versions are affected by CVE-2024-38664? It affects 1 product. Products: Linux kernel. ## How do I fix CVE-2024-38664? Apply the vendor's patch. ## Is CVE-2024-38664 being exploited? There is no known exploitation of CVE-2024-38664 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-2024-38664 and fix it if it is affected. What it is: CVE-2024-38664 is a high-severity vulnerability in Linux kernel, published on 24 Jun 2024. 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-2024-38664 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-2024-38664/ (Markdown: https://insights.sbomify.com/CVE-2024-38664/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2024-38664 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-38664 - OSV: https://osv.dev/vulnerability/CVE-2024-38664 --- From sbomify Insights: https://insights.sbomify.com/CVE-2024-38664/ Summaries are generated and may contain mistakes; the official description above is the record.