# CVE-2024-47717: RISC-V: KVM: Don't zero-out PMU snapshot area before freeing data > A NULL pointer dereference in the Linux kernel's RISC-V KVM PMU handling allows a local attacker to cause a system crash by forcefully powering off a guest. - **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:** 21 Oct 2024 - **Updated:** 11 May 2026 - **Also known as:** BELL-CVE-2024-47717, DEBIAN-CVE-2024-47717, GHSA-p83g-x445-4qm2, UBUNTU-CVE-2024-47717 ## What is CVE-2024-47717? CVE-2024-47717 is a medium-severity vulnerability in Linux kernel, published on 21 Oct 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: RISC-V: KVM: Don't zero-out PMU snapshot area before freeing data With the latest Linux-6.11-rc3, the below NULL pointer crash is observed when SBI PMU snapshot is enabled for the guest and the guest is forcefully powered-off. Unable to handle kernel NULL pointer dereference at virtual address 0000000000000508 Oops [#1] Modules linked in: kvm CPU: 0 UID: 0 PID: 61 Comm: term-poll Not tainted 6.11.0-rc3-00018-g44d7178dd77a #3 Hardware name: riscv-virtio,qemu (DT) epc : __kvm_write_guest_page+0x94/0xa6 [kvm] ra : __kvm_write_guest_page+0x54/0xa6 [kvm] epc : ffffffff01590e98 ra : ffffffff01590e58 sp : ffff8f80001f39b0 gp : ffffffff81512a60 tp : ffffaf80024872c0 t0 : ffffaf800247e000 t1 : 00000000000007e0 t2 : 0000000000000000 s0 : ffff8f80001f39f0 s1 : 00007fff89ac4000 a0 : ffffffff015dd7e8 a1 : 0000000000000086 a2 : 0000000000000000 a3 : ffffaf8000000000 a4 : ffffaf80024882c0 a5 : 0000000000000000 a6 : ffffaf800328d780 a7 : 00000000000001cc s2 : ffffaf800197bd00 s3 : 00000000000828c4 s4 : ffffaf800248c000 s5 : ffffaf800247d000 s6 : 0000000000001000 s7 : 0000000000001000 s8 : 0000000000000000 s9 : 00007fff861fd500 s10: 0000000000000001 s11: 0000000000800000 t3 : 00000000000004d3 t4 : 00000000000004d3 t5 : ffffffff814126e0 t6 : ffffffff81412700 status: 0000000200000120 badaddr: 0000000000000508 cause: 000000000000000d [] __kvm_write_guest_page+0x94/0xa6 [kvm] [] kvm_vcpu_write_guest+0x56/0x90 [kvm] [] kvm_pmu_clear_snapshot_area+0x42/0x7e [kvm] [] kvm_riscv_vcpu_pmu_deinit.part.0+0xe0/0x14e [kvm] [] kvm_riscv_vcpu_pmu_deinit+0x1a/0x24 [kvm] [] kvm_arch_vcpu_destroy+0x28/0x4c [kvm] [] kvm_destroy_vcpus+0x5a/0xda [kvm] [] kvm_arch_destroy_vm+0x14/0x28 [kvm] [] kvm_destroy_vm+0x168/0x2a0 [kvm] [] kvm_put_kvm+0x3c/0x58 [kvm] [] kvm_vm_release+0x22/0x2e [kvm] Clearly, the kvm_vcpu_write_guest() function is crashing because it is being called from kvm_pmu_clear_snapshot_area() upon guest tear down. To address the above issue, simplify the kvm_pmu_clear_snapshot_area() to not zero-out PMU snapshot area from kvm_pmu_clear_snapshot_area() because the guest is anyway being tore down. The kvm_pmu_clear_snapshot_area() is also called when guest changes PMU snapshot area of a VCPU but even in this case the previous PMU snaphsot area must not be zeroed-out because the guest might have reclaimed the pervious PMU snapshot area for some other purpose. Weakness: CWE-476 (NULL Pointer Dereference) ## Which versions are affected by CVE-2024-47717? It affects 1 product. Products: Linux kernel. ## How do I fix CVE-2024-47717? Apply the vendor's patch. ## Is CVE-2024-47717 being exploited? There is no known exploitation of CVE-2024-47717 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-2024-47717 and fix it if it is affected. What it is: CVE-2024-47717 is a medium-severity vulnerability in Linux kernel, published on 21 Oct 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-2024-47717 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-2024-47717/ (Markdown: https://insights.sbomify.com/CVE-2024-47717/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2024-47717 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-47717 - OSV: https://osv.dev/vulnerability/CVE-2024-47717 --- From sbomify Insights: https://insights.sbomify.com/CVE-2024-47717/ Summaries are generated and may contain mistakes; the official description above is the record.