# CVE-2024-56702: bpf: Mark raw_tp arguments with PTR_MAYBE_NULL > A null pointer dereference in the Linux kernel BPF subsystem can cause a kernel crash when raw tracepoint arguments are unexpectedly NULL. - **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:** 28 Dec 2024 - **Updated:** 21 Oct 2026 - **Also known as:** AZL-56294, BELL-CVE-2024-56702, DEBIAN-CVE-2024-56702, GHSA-cvxq-qv5g-cqw6, ROOT-OS-UBUNTU-2404-CVE-2024-56702, UBUNTU-CVE-2024-56702 ## What is CVE-2024-56702? CVE-2024-56702 is a medium-severity vulnerability in Linux kernel, published on 28 Dec 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: bpf: Mark raw_tp arguments with PTR_MAYBE_NULL Arguments to a raw tracepoint are tagged as trusted, which carries the semantics that the pointer will be non-NULL. However, in certain cases, a raw tracepoint argument may end up being NULL. More context about this issue is available in [0]. Thus, there is a discrepancy between the reality, that raw_tp arguments can actually be NULL, and the verifier's knowledge, that they are never NULL, causing explicit NULL checks to be deleted, and accesses to such pointers potentially crashing the kernel. To fix this, mark raw_tp arguments as PTR_MAYBE_NULL, and then special case the dereference and pointer arithmetic to permit it, and allow passing them into helpers/kfuncs; these exceptions are made for raw_tp programs only. Ensure that we don't do this when ref_obj_id > 0, as in that case this is an acquired object and doesn't need such adjustment. The reason we do mask_raw_tp_trusted_reg logic is because other will recheck in places whether the register is a trusted_reg, and then consider our register as untrusted when detecting the presence of the PTR_MAYBE_NULL flag. To allow safe dereference, we enable PROBE_MEM marking when we see loads into trusted pointers with PTR_MAYBE_NULL. While trusted raw_tp arguments can also be passed into helpers or kfuncs where such broken assumption may cause issues, a future patch set will tackle their case separately, as PTR_TO_BTF_ID (without PTR_TRUSTED) can already be passed into helpers and causes similar problems. Thus, they are left alone for now. It is possible that these checks also permit passing non-raw_tp args that are trusted PTR_TO_BTF_ID with null marking. In such a case, allowing dereference when pointer is NULL expands allowed behavior, so won't regress existing programs, and the case of passing these into helpers is the same as above and will be dealt with later. Also update the failure case in tp_btf_nullable selftest to capture the new behavior, as the verifier will no longer cause an error when directly dereference a raw tracepoint argument marked as __nullable. [0]: https://lore.kernel.org/bpf/ZrCZS6nisraEqehw@jlelli-thinkpadt14gen4.remote.csb Weakness: CWE-476 (NULL Pointer Dereference) ## Which versions are affected by CVE-2024-56702? It affects 1 product. Products: Linux kernel. ## How do I fix CVE-2024-56702? Apply the vendor's patch. ## Is CVE-2024-56702 being exploited? There is no known exploitation of CVE-2024-56702 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-2024-56702 and fix it if it is affected. What it is: CVE-2024-56702 is a medium-severity vulnerability in Linux kernel, published on 28 Dec 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-2024-56702 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-2024-56702/ (Markdown: https://insights.sbomify.com/CVE-2024-56702/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2024-56702 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-56702 - OSV: https://osv.dev/vulnerability/CVE-2024-56702 --- From sbomify Insights: https://insights.sbomify.com/CVE-2024-56702/ Summaries are generated and may contain mistakes; the official description above is the record.