{"id":"CVE-2026-89513","title":"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","summary":"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…","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","cwe":["CWE-787"],"vendor":"Linux","product":"Linux","affected":["Linux >= e309fd113b9f6c34672a487be08fecb7e12e7e29 < ddbd71a3780942918a7d116d666313e5b3304d73","Linux >= e309fd113b9f6c34672a487be08fecb7e12e7e29 < 82088f88c96b99c27a974d09b02c2b133262fadf","Linux >= e309fd113b9f6c34672a487be08fecb7e12e7e29 < 735bc20c24187ca419c9d5e63860a54b91be34bd","Linux 6.18"],"published":"2026-09-11","updated":"2026-10-15","sourceUpdated":"2026-10-15T11:17:53.707","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-89513","references":[{"url":"https://git.kernel.org/stable/c/735bc20c24187ca419c9d5e63860a54b91be34bd","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/82088f88c96b99c27a974d09b02c2b133262fadf","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ddbd71a3780942918a7d116d666313e5b3304d73","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89513.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89513"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532187"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89513"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89513"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89513.mbox"}],"tags":["nvd","cve.org","csaf","vex","red-hat","score-dispute"],"epss":0.00173,"epssPercentile":0.06729,"scores":{"nvd":8.8,"cna":8.8,"vendor":5.5},"ingestedAt":"2026-09-14T15:23:07.475Z","slug":"CVE-2026-89513","body":"## Overview\n\nIn 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[<ffffffff8006471c>] kvm_riscv_vcpu_pmu_event_info+0xa4/0x142\n[<ffffffff800690c0>] kvm_sbi_ext_pmu_handler+0xca/0x268\n[<ffffffff8006779e>] kvm_riscv_vcpu_sbi_ecall+0xec/0x1e6\n[<ffffffff8006008c>] kvm_riscv_vcpu_exit+0x48c/0x540\n[<ffffffff8005ea0a>] 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · updated 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89513.json)","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":48.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":222169,"id":"CVE-2026-89513","ts":1792062154682,"field":"cvss","old":"5.5","new":"8.8"},{"seq":222168,"id":"CVE-2026-89513","ts":1792062154682,"field":"severity","old":"medium","new":"high"},{"seq":206934,"id":"CVE-2026-89513","ts":1789749706648,"field":"cvss","old":"7","new":"5.5"},{"seq":206933,"id":"CVE-2026-89513","ts":1789749706648,"field":"severity","old":"high","new":"medium"},{"seq":203028,"id":"CVE-2026-89513","ts":1789403733410,"field":"cvss","old":"8.8","new":"7"},{"seq":197984,"id":"CVE-2026-89513","ts":1789384321255,"field":"cvss","old":"7","new":"8.8"},{"seq":183773,"id":"CVE-2026-89513","ts":1789356677329,"field":"cvss","old":"8.8","new":"7"},{"seq":153306,"id":"CVE-2026-89513","ts":1789285349971,"field":"cvss","old":null,"new":"8.8"},{"seq":153305,"id":"CVE-2026-89513","ts":1789285349971,"field":"severity","old":"none","new":"high"},{"seq":147628,"id":"CVE-2026-89513","ts":1789270211655,"field":"cvss","old":null,"new":"7"},{"seq":147627,"id":"CVE-2026-89513","ts":1789270211655,"field":"severity","old":"none","new":"high"},{"seq":109380,"id":"CVE-2026-89513","ts":1789183731682,"field":"cvss","old":null,"new":"7"},{"seq":109379,"id":"CVE-2026-89513","ts":1789183731682,"field":"severity","old":"none","new":"high"}]}