{"id":"CVE-2026-98283","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: PPC: Book3S HV: fix use-after-free in kvmhv_emulate_tlbie_all_lpid()\n\nkvmhv_emulate_tlbie_all_lpid() iterates the nested-guest IDR and drops\nmmu_lock before callin…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: PPC: Book3S HV: fix use-after-free in kvmhv_emulate_tlbie_all_lpid()\n\nkvmhv_emulate_tlbie_all_lpid() iterates the nested-guest IDR and drops\nmmu_lock before callin…","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","vendor":"Linux","product":"Linux","affected":["Linux >= e3b6b4661527e821ffbe3db83952fdb1e6e47c49 < 4d8f7b1f586375df8bce23a0909566ad5e852259","Linux >= e3b6b4661527e821ffbe3db83952fdb1e6e47c49 < e37fba1ba69385cff2d0e60b371ee19e7d1852d1","Linux >= e3b6b4661527e821ffbe3db83952fdb1e6e47c49 < 24b634852413229bb8340d908b115c3365f3a247","Linux >= e3b6b4661527e821ffbe3db83952fdb1e6e47c49 < fbf69b7d0555ee83c871f58750770f74b7179ad1","Linux >= e3b6b4661527e821ffbe3db83952fdb1e6e47c49 < ec2d7a52b3996ae81131617b4afc0af31583c1b4","Linux >= e3b6b4661527e821ffbe3db83952fdb1e6e47c49 < 51938dfa8a51a4f85328413fca9b6e21f9d2d088","Linux 4.20"],"published":"2026-10-06","updated":"2026-10-07","sourceUpdated":"2026-10-07T07:17:08.070","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-98283","references":[{"url":"https://git.kernel.org/stable/c/24b634852413229bb8340d908b115c3365f3a247","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4d8f7b1f586375df8bce23a0909566ad5e852259","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/51938dfa8a51a4f85328413fca9b6e21f9d2d088","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e37fba1ba69385cff2d0e60b371ee19e7d1852d1","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ec2d7a52b3996ae81131617b4afc0af31583c1b4","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/fbf69b7d0555ee83c871f58750770f74b7179ad1","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98283.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-98283"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2546507"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98283"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98283"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98283.mbox"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"epss":0.00126,"epssPercentile":0.02242,"ingestedAt":"2026-10-06T08:50:17.421Z","cwe":["CWE-825"],"scores":{"nvd":8.8,"vendor":7,"cna":8.8},"slug":"CVE-2026-98283","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nKVM: PPC: Book3S HV: fix use-after-free in kvmhv_emulate_tlbie_all_lpid()\n\nkvmhv_emulate_tlbie_all_lpid() iterates the nested-guest IDR and drops\nmmu_lock before calling kvmhv_emulate_tlbie_lpid(), but does not hold a\nreference on the kvm_nested_guest pointer obtained from the IDR.  A\nconcurrent vCPU issuing a single-LPID tlbie (is=2, ric=2) can race\nthrough kvmhv_flush_nested() -> kvmhv_remove_nested() -> idr_remove /\n--refcnt -> kvmhv_release_nested() -> kfree(gp) in that window, leaving\nthe iterating vCPU with a dangling pointer.  The subsequent\nmutex_lock(&gp->tlb_lock) and accesses to gp->shadow_pgtable,\ngp->shadow_lpid and gp->l1_host all touch freed memory.  The free path\nis fully L1-controlled.\n\nFix this by incrementing gp->refcnt inside the loop before dropping\nmmu_lock, mirroring what kvmhv_get_nested() does, and releasing the\nreference with kvmhv_put_nested() after the per-guest work completes.\nThis is the same get/put discipline already used at every other\ncall site that drops mmu_lock while holding a nested-guest pointer.\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 · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat OpenShift Container Platform 4 · updated 2026-10-10 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98283.json)","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":48.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":217312,"id":"CVE-2026-98283","ts":1791361312176,"field":"cvss","old":null,"new":"8.8"},{"seq":217311,"id":"CVE-2026-98283","ts":1791361312176,"field":"severity","old":"none","new":"high"}]}