# CVE-2021-47436: usb: musb: dsps: Fix the probe error path > A missing cleanup in the Linux kernel USB driver error path causes a null pointer dereference and system crash during boot on specific hardware. - **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 May 2024 - **Updated:** 23 May 2026 - **Also known as:** DEBIAN-CVE-2021-47436, GHSA-6xwm-63wf-q2q3, UBUNTU-CVE-2021-47436 ## What is CVE-2021-47436? CVE-2021-47436 is a medium-severity vulnerability in Linux kernel, published on 22 May 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: usb: musb: dsps: Fix the probe error path Commit 7c75bde329d7 ("usb: musb: musb_dsps: request_irq() after initializing musb") has inverted the calls to dsps_setup_optional_vbus_irq() and dsps_create_musb_pdev() without updating correctly the error path. dsps_create_musb_pdev() allocates and registers a new platform device which must be unregistered and freed with platform_device_unregister(), and this is missing upon dsps_setup_optional_vbus_irq() error. While on the master branch it seems not to trigger any issue, I observed a kernel crash because of a NULL pointer dereference with a v5.10.70 stable kernel where the patch mentioned above was backported. With this kernel version, -EPROBE_DEFER is returned the first time dsps_setup_optional_vbus_irq() is called which triggers the probe to error out without unregistering the platform device. Unfortunately, on the Beagle Bone Black Wireless, the platform device still living in the system is being used by the USB Ethernet gadget driver, which during the boot phase triggers the crash. My limited knowledge of the musb world prevents me to revert this commit which was sent to silence a robot warning which, as far as I understand, does not make sense. The goal of this patch was to prevent an IRQ to fire before the platform device being registered. I think this cannot ever happen due to the fact that enabling the interrupts is done by the ->enable() callback of the platform musb device, and this platform device must be already registered in order for the core or any other user to use this callback. Hence, I decided to fix the error path, which might prevent future errors on mainline kernels while also fixing older ones. Weakness: CWE-476 (NULL Pointer Dereference) ## Which versions are affected by CVE-2021-47436? It affects 1 product. Products: Linux kernel. ## How do I fix CVE-2021-47436? Apply the vendor's patch. ## Is CVE-2021-47436 being exploited? There is no known exploitation of CVE-2021-47436 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-2021-47436 and fix it if it is affected. What it is: CVE-2021-47436 is a medium-severity vulnerability in Linux kernel, published on 22 May 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-2021-47436 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-2021-47436/ (Markdown: https://insights.sbomify.com/CVE-2021-47436/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2021-47436 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-47436 - OSV: https://osv.dev/vulnerability/CVE-2021-47436 --- From sbomify Insights: https://insights.sbomify.com/CVE-2021-47436/ Summaries are generated and may contain mistakes; the official description above is the record.