{"id":"CVE-2026-99168","aliases":[],"title":"mshv_vtl: Check per-CPU register page before mmap","titleSource":"Linux","descriptionSource":"Linux","products":[{"vendor":"Linux","name":"Linux","platforms":[],"versions":[{"version":"7bfe3b8ea6e30437e01fcb8e4f56ef6e4d986d0f","status":"affected","lessThan":"5c0757b065fbd140d8fbd05dc2c2146b713dfa68","versionType":"git"},{"version":"7bfe3b8ea6e30437e01fcb8e4f56ef6e4d986d0f","status":"affected","lessThan":"874194a8de75fc2f4d1fb70c670b289b7e48f93e","versionType":"git"}],"defaultStatus":"unaffected","source":"Linux","url":"https://www.cve.org/CVERecord?id=CVE-2026-99168"},{"vendor":"Linux","name":"Linux","platforms":[],"versions":[{"version":"6.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.19","versionType":"semver"},{"version":"7.2.13","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"defaultStatus":"affected","source":"Linux","url":"https://www.cve.org/CVERecord?id=CVE-2026-99168"}],"remediation":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmshv_vtl: Check per-CPU register page before mmap\n\nRegister-page setup is optional for each CPU. If allocation or\nregistration fails, mshv_vtl_configure_reg_page() warns and leaves that\nCPU's reg_page NULL, but initial context setup continues successfully.\nMeanwhile, successful setup on another CPU sets the global\nmshv_has_reg_page flag.\n\nmshv_vtl_fault() checks this global flag before selecting the requested\nCPU's register page. With mixed setup results across online CPUs, the\ncheck passes even for a CPU with no register page, reaching\nget_page(NULL) when userspace faults in that mapping.\n\nCheck the selected per-CPU register page before taking its reference and\nreturn VM_FAULT_SIGBUS if it is absent.","severity":"unknown","score":null,"published":"2026-10-28T10:35:19.539Z","modified":"2026-10-28T10:35:19.539Z","withdrawn":false,"knownExploited":false,"affected":[],"references":["https://git.kernel.org/stable/c/5c0757b065fbd140d8fbd05dc2c2146b713dfa68","https://git.kernel.org/stable/c/874194a8de75fc2f4d1fb70c670b289b7e48f93e"],"sources":[{"name":"CVE","id":"CVE-2026-99168","modified":"2026-10-28T10:35:19.539Z","url":"https://www.cve.org/CVERecord?id=CVE-2026-99168"}],"assessments":[],"sourceAffected":[],"kev":{"status":"not-listed","checkedAt":"2026-10-28T22:25:35.093Z"},"coverage":[{"source":"NVD","status":"not-checked"},{"source":"GHSA","status":"not-checked"},{"source":"EUVD","status":"not-checked"},{"source":"EPSS","status":"not-checked"}],"evidence":[]}