CVE-2024-47717

CVE-2024-47717 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-476.

Key facts

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 [<ffffffff01590e98>] __kvm_write_guest_page+0x94/0xa6 [kvm] [<ffffffff015943a6>] kvm_vcpu_write_guest+0x56/0x90 [kvm] [<ffffffff015a175c>] kvm_pmu_clear_snapshot_area+0x42/0x7e [kvm] [<ffffffff015a1972>] kvm_riscv_vcpu_pmu_deinit.part.0+0xe0/0x14e [kvm] [<ffffffff015a2ad0>] kvm_riscv_vcpu_pmu_deinit+0x1a/0x24 [kvm] [<ffffffff0159b344>] kvm_arch_vcpu_destroy+0x28/0x4c [kvm] [<ffffffff0158e420>] kvm_destroy_vcpus+0x5a/0xda [kvm] [<ffffffff0159930c>] kvm_arch_destroy_vm+0x14/0x28 [kvm] [<ffffffff01593260>] kvm_destroy_vm+0x168/0x2a0 [kvm] [<ffffffff015933d4>] kvm_put_kvm+0x3c/0x58 [kvm] [<ffffffff01593412>] 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.

Frequently asked questions

What is CVE-2024-47717?
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 [<ffffffff01590e98>] __kvm_write_guest_page+0x94/0xa6 [kvm] [<ffffffff015943a6>] kvm_vcpu_write_guest+0x56/0x90 [kvm] [<ffffffff015a175c>] kvm_pmu_clear_snapshot_area+0x42/0x7e [kvm] [<ffffffff015a1972>] kvm_riscv_vcpu_pmu_deinit.part.0+0xe0/0x14e [kvm] [<ffffffff015a2ad0>] kvm_riscv_vcpu_pmu_deinit+0x1a/0x24 [kvm] [<ffffffff0159b344>] kvm_arch_vcpu_destroy+0x28/0x4c [kvm] [<ffffffff0158e420>] kvm_destroy_vcpus+0x5a/0xda [kvm] [<ffffffff0159930c>] kvm_arch_destroy_vm+0x14/0x28 [kvm] [<ffffffff01593260>] kvm_destroy_vm+0x168/0x2a0 [kvm] [<ffffffff015933d4>] kvm_put_kvm+0x3c/0x58 [kvm] [<ffffffff01593412>] 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.
How severe is CVE-2024-47717?
CVE-2024-47717 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2024-47717 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (12th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-47717?
CVE-2024-47717 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2024-47717?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2024-47717 have an EU (EUVD) identifier?
Yes. CVE-2024-47717 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-42636.
When was CVE-2024-47717 published?
CVE-2024-47717 was published on 2024-10-21 and last updated on 2026-06-17.

References

Affected products (1)

More vulnerabilities in Linux Linux Kernel

All CVEs affecting Linux Linux Kernel →

Other CWE-476 (NULL Pointer Dereference) vulnerabilities

Browse all CWE-476 (NULL Pointer Dereference) vulnerabilities →