{"id":"CVE-2026-89513","summary":"RISC-V: KVM: Fix PMU event info array size overflow","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nRISC-V: KVM: Fix PMU event info array size overflow\n\nSBI PMU EVENT_GET_INFO stores guest-controlled num_events * sizeof(*einfo)\nin a 32-bit integer. On RV64, num_events = 0x10000001 makes 0x100000010\ntruncate to 16. KVM then allocates one entry but loops over the original\nnum_events, causing out-of-bounds reads and writes. A nested guest\ntriggered:\n\nBUG: KASAN: slab-out-of-bounds in kvm_riscv_vcpu_pmu_event_info+0xa4/0x142\nRead of size 4 at addr ff600000074d46b0 by task init/1\nCall Trace:\n[\u003cffffffff8006471c\u003e] kvm_riscv_vcpu_pmu_event_info+0xa4/0x142\n[\u003cffffffff800690c0\u003e] kvm_sbi_ext_pmu_handler+0xca/0x268\n[\u003cffffffff8006779e\u003e] kvm_riscv_vcpu_sbi_ecall+0xec/0x1e6\n[\u003cffffffff8006008c\u003e] kvm_riscv_vcpu_exit+0x48c/0x540\n[\u003cffffffff8005ea0a\u003e] kvm_arch_vcpu_ioctl_run+0x37e/0xc80\nAllocated by task 1:\n __kmalloc_noprof+0x19e/0x4b0\n kvm_riscv_vcpu_pmu_event_info+0x72/0x142\n kvm_sbi_ext_pmu_handler+0xca/0x268\n kvm_riscv_vcpu_sbi_ecall+0xec/0x1e6\n kvm_riscv_vcpu_exit+0x48c/0x540\n kvm_arch_vcpu_ioctl_run+0x37e/0xc80\nThe buggy address is located 0 bytes to the right of\n allocated 16-byte region [ff600000074d46a0, ff600000074d46b0)\n\nStore the shared-memory size in size_t and reject multiplication overflow.\nAllocate the guest-driven array with GFP_KERNEL_ACCOUNT so it is charged\nto kmemcg, and use __GFP_NOWARN to suppress allocation failure warnings.\nUse kvcalloc() to allow vmalloc fallback and an unsigned long loop index\nto match num_events.","modified":"2026-09-14T03:46:06.555429843Z","published":"2026-09-11T19:43:57.960Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89513.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/735bc20c24187ca419c9d5e63860a54b91be34bd"},{"type":"WEB","url":"https://git.kernel.org/stable/c/82088f88c96b99c27a974d09b02c2b133262fadf"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89513.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89513"},{"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":"e309fd113b9f6c34672a487be08fecb7e12e7e29"},{"fixed":"82088f88c96b99c27a974d09b02c2b133262fadf"},{"fixed":"735bc20c24187ca419c9d5e63860a54b91be34bd"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89513.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.18.0"},{"fixed":"7.2.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89513.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H"}]}