{"cve":"CVE-2026-68428","nvd":{"published":"2026-08-10T13:20:36.770","modified":"2026-08-19T17:20:49.760","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86/mmu: Fix use-after-free on vendor module reload\n\nmmu_destroy_caches() destroys pte_list_desc_cache and\nmmu_page_header_cache, but leaves both pointers unchanged.  The pointers\nlive in kvm.ko, and therefore survive when a vendor module is unloaded\nwhile kvm.ko remains loaded.\n\nIf creation of pte_list_desc_cache fails during a subsequent vendor\nmodule load, its assignment sets pte_list_desc_cache to NULL and the\nerror path calls mmu_destroy_caches().  mmu_page_header_cache still\npoints to the cache destroyed during the preceding vendor module\nunload.  Passing that stale pointer to kmem_cache_destroy() causes a\nslab use-after-free.\n\nReproduce the issue on a v7.1.3 kernel with CONFIG_KASAN=y,\nCONFIG_KASAN_GENERIC=y, CONFIG_KVM=m, and CONFIG_KVM_INTEL=m.  A\none-shot test hook forces pte_list_desc_cache to NULL on the second\ninvocation of kvm_mmu_vendor_module_init():\n\n  1. Load kvm.ko and kvm-intel.ko, creating both caches.\n  2. Unload only kvm_intel, leaving kvm.ko loaded.\n  3. Reload kvm_intel and force initialization through the -ENOMEM path.\n\nKASAN reports:\n\n  BUG: KASAN: slab-use-after-free in\n  kvm_mmu_vendor_module_init+0x5b/0x170 [kvm]\n  ...\n  kmem_cache_destroy+0x21/0x1d0\n  kvm_mmu_vendor_module_init+0x5b/0x170 [kvm]\n  ...\n  Allocated by task 16817:\n  __kmem_cache_create_args+0x12c/0x3b0\n  __kmem_cache_create.constprop.0+0xb6/0xf0 [kvm]\n  kvm_mmu_vendor_module_init+0x13b/0x170 [kvm]\n  ...\n  Freed by task 16820:\n  kmem_cache_destroy+0x117/0x1d0\n  kvm_mmu_vendor_module_exit+0x21/0x30 [kvm]\n\nClear both pointers immediately after destroying their caches so that\nthe stored state reflects the caches' lifetime and repeated cleanup is\nsafe.\n\nWith the fix applied, the same injected vendor module reload fails with\n-ENOMEM as expected and produces no KASAN report.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/034b7fa1f5846d69eb51f12ce6d1c71871e83c2d","https://git.kernel.org/stable/c/32b9f89ed9e6d7a45075d64089c254a7f6e13695","https://git.kernel.org/stable/c/42272b0f239f3a89f9c26a01cc37aee06138b1b7","https://git.kernel.org/stable/c/43cfb20d62ffe49626d62beecfc32eb6f262191c","https://git.kernel.org/stable/c/52f2f7c30126037975389aa04d24c506a5177c35"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:47:54.990491175+00:00"},"epss":{"cve":"CVE-2026-68428","score":0.00165,"percentile":0.0566,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}