CVE-2026-89513
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: RISC-V: KVM: Fix PMU event info array size overflow SBI PMU EVENT_GET_INFO stores guest-controlled num_events * sizeof(*einfo) in a 32-bit integer. On RV64, num_events = 0x10000001 makes 0x100000010 truncate to 16. KVM then allocates one entry but loops over the original num_events, causing out-of-bounds reads and writes. A nested guest triggered: BUG: KASAN: slab-out-of-bounds in kvm_riscv_vcpu_pmu_event_info+0xa4/0x142 Read of size 4 at addr ff600000074d46b0 by task init/1 Call Trace: [<ffffffff8006471c>] kvm_riscv_vcpu_pmu_event_info+0xa4/0x142 [<ffffffff800690c0>] kvm_sbi_ext_pmu_handler+0xca/0x268 [<ffffffff8006779e>] kvm_riscv_vcpu_sbi_ecall+0xec/0x1e6 [<ffffffff8006008c>] kvm_riscv_vcpu_exit+0x48c/0x540 [<ffffffff8005ea0a>] kvm_arch_vcpu_ioctl_run+0x37e/0xc80 Allocated by task 1: __kmalloc_noprof+0x19e/0x4b0 kvm_riscv_vcpu_pmu_event_info+0x72/0x142 kvm_sbi_ext_pmu_handler+0xca/0x268 kvm_riscv_vcpu_sbi_ecall+0xec/0x1e6 kvm_riscv_vcpu_exit+0x48c/0x540 kvm_arch_vcpu_ioctl_run+0x37e/0xc80 The buggy address is located 0 bytes to the right of allocated 16-byte region [ff600000074d46a0, ff600000074d46b0) Store the shared-memory size in size_t and reject multiplication overflow. Allocate the guest-driven array with GFP_KERNEL_ACCOUNT so it is charged to kmemcg, and use __GFP_NOWARN to suppress allocation failure warnings. Use kvcalloc() to allow vmalloc fallback and an unsigned long loop index to match num_events.
View original CVE JSON
{
"id": "CVE-2026-89513",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-09-11T20:19:33.787",
"lastModified": "2026-10-19T09:17:45.717",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "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[<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."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"arch/riscv/kvm/vcpu_pmu.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "e309fd113b9f6c34672a487be08fecb7e12e7e29",
"lessThan": "ddbd71a3780942918a7d116d666313e5b3304d73",
"versionType": "git",
"status": "affected"
},
{
"version": "e309fd113b9f6c34672a487be08fecb7e12e7e29",
"lessThan": "82088f88c96b99c27a974d09b02c2b133262fadf",
"versionType": "git",
"status": "affected"
},
{
"version": "e309fd113b9f6c34672a487be08fecb7e12e7e29",
"lessThan": "735bc20c24187ca419c9d5e63860a54b91be34bd",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"arch/riscv/kvm/vcpu_pmu.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "6.18",
"status": "affected"
},
{
"version": "0",
"lessThan": "6.18",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.57",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.4",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
"baseScore": 8.8,
"baseSeverity": "HIGH",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "CHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 2.0,
"impactScore": 6.0
}
]
},
"references": [
{
"url": "https://git.kernel.org/stable/c/735bc20c24187ca419c9d5e63860a54b91be34bd",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/82088f88c96b99c27a974d09b02c2b133262fadf",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/ddbd71a3780942918a7d116d666313e5b3304d73",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}