{"id":"CVE-2024-47717","summary":"RISC-V: KVM: Don't zero-out PMU snapshot area before freeing data","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nRISC-V: KVM: Don't zero-out PMU snapshot area before freeing data\n\nWith the latest Linux-6.11-rc3, the below NULL pointer crash is observed\nwhen SBI PMU snapshot is enabled for the guest and the guest is forcefully\npowered-off.\n\n  Unable to handle kernel NULL pointer dereference at virtual address 0000000000000508\n  Oops [#1]\n  Modules linked in: kvm\n  CPU: 0 UID: 0 PID: 61 Comm: term-poll Not tainted 6.11.0-rc3-00018-g44d7178dd77a #3\n  Hardware name: riscv-virtio,qemu (DT)\n  epc : __kvm_write_guest_page+0x94/0xa6 [kvm]\n   ra : __kvm_write_guest_page+0x54/0xa6 [kvm]\n  epc : ffffffff01590e98 ra : ffffffff01590e58 sp : ffff8f80001f39b0\n   gp : ffffffff81512a60 tp : ffffaf80024872c0 t0 : ffffaf800247e000\n   t1 : 00000000000007e0 t2 : 0000000000000000 s0 : ffff8f80001f39f0\n   s1 : 00007fff89ac4000 a0 : ffffffff015dd7e8 a1 : 0000000000000086\n   a2 : 0000000000000000 a3 : ffffaf8000000000 a4 : ffffaf80024882c0\n   a5 : 0000000000000000 a6 : ffffaf800328d780 a7 : 00000000000001cc\n   s2 : ffffaf800197bd00 s3 : 00000000000828c4 s4 : ffffaf800248c000\n   s5 : ffffaf800247d000 s6 : 0000000000001000 s7 : 0000000000001000\n   s8 : 0000000000000000 s9 : 00007fff861fd500 s10: 0000000000000001\n   s11: 0000000000800000 t3 : 00000000000004d3 t4 : 00000000000004d3\n   t5 : ffffffff814126e0 t6 : ffffffff81412700\n  status: 0000000200000120 badaddr: 0000000000000508 cause: 000000000000000d\n  [\u003cffffffff01590e98\u003e] __kvm_write_guest_page+0x94/0xa6 [kvm]\n  [\u003cffffffff015943a6\u003e] kvm_vcpu_write_guest+0x56/0x90 [kvm]\n  [\u003cffffffff015a175c\u003e] kvm_pmu_clear_snapshot_area+0x42/0x7e [kvm]\n  [\u003cffffffff015a1972\u003e] kvm_riscv_vcpu_pmu_deinit.part.0+0xe0/0x14e [kvm]\n  [\u003cffffffff015a2ad0\u003e] kvm_riscv_vcpu_pmu_deinit+0x1a/0x24 [kvm]\n  [\u003cffffffff0159b344\u003e] kvm_arch_vcpu_destroy+0x28/0x4c [kvm]\n  [\u003cffffffff0158e420\u003e] kvm_destroy_vcpus+0x5a/0xda [kvm]\n  [\u003cffffffff0159930c\u003e] kvm_arch_destroy_vm+0x14/0x28 [kvm]\n  [\u003cffffffff01593260\u003e] kvm_destroy_vm+0x168/0x2a0 [kvm]\n  [\u003cffffffff015933d4\u003e] kvm_put_kvm+0x3c/0x58 [kvm]\n  [\u003cffffffff01593412\u003e] kvm_vm_release+0x22/0x2e [kvm]\n\nClearly, the kvm_vcpu_write_guest() function is crashing because it is\nbeing called from kvm_pmu_clear_snapshot_area() upon guest tear down.\n\nTo address the above issue, simplify the kvm_pmu_clear_snapshot_area() to\nnot zero-out PMU snapshot area from kvm_pmu_clear_snapshot_area() because\nthe guest is anyway being tore down.\n\nThe kvm_pmu_clear_snapshot_area() is also called when guest changes\nPMU snapshot area of a VCPU but even in this case the previous PMU\nsnaphsot area must not be zeroed-out because the guest might have\nreclaimed the pervious PMU snapshot area for some other purpose.","modified":"2026-05-18T05:57:17.814691773Z","published":"2024-10-21T11:53:48.181Z","related":["USN-7276-1","USN-7277-1","openSUSE-SU-2024:14500-1","openSUSE-SU-2025:14705-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/47xxx/CVE-2024-47717.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/47d40d93292d9cff8dabb735bed83d930fa03950"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6d0a5dcfc78bd18f2abb9641f83380135494559b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/81aa95fd5bd14ff49617f07fa79a8d1f1cf2ce9a"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/47xxx/CVE-2024-47717.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-47717"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"c2f41ddbcdd75689d9f512638a40263e3127be93"},{"fixed":"81aa95fd5bd14ff49617f07fa79a8d1f1cf2ce9a"},{"fixed":"6d0a5dcfc78bd18f2abb9641f83380135494559b"},{"fixed":"47d40d93292d9cff8dabb735bed83d930fa03950"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2024-47717.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.10.0"},{"fixed":"6.10.13"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.11.0"},{"fixed":"6.11.2"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2024-47717.json"}}],"schema_version":"1.7.5"}