{"id":"CVE-2026-97478","aliases":[],"cve":{"records":[{"id":"CVE-2026-97478","source":"Linux","state":"PUBLISHED","reasons":[],"replacements":[],"disputed":false,"unsupportedWhenAssigned":false,"reserved":"2026-09-24T16:01:01.149Z","published":"2026-09-24T16:04:20.263Z","modified":"2026-10-30T12:36:59.771Z"}],"publishers":[{"name":"Linux","role":"CNA","organizationId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","modified":"2026-10-30T12:36:59.771Z"}],"references":[{"url":"https://git.kernel.org/stable/c/dccf23a72a6c5ec8d9eab2a7f98e186af6eaff48","tags":[],"source":"Linux"},{"url":"https://git.kernel.org/stable/c/6e9e007ee1dfb54bc2d070550308077ec28dbaec","tags":[],"source":"Linux"},{"url":"https://git.kernel.org/stable/c/0e1152f689847b9db2f05454775d34610c1424c2","tags":[],"source":"Linux"},{"url":"https://git.kernel.org/stable/c/d8156aacfcabb81f52c20ef89094945434d08079","tags":[],"source":"Linux"},{"url":"https://git.kernel.org/stable/c/666c7f9e07925aa0863348f960e09bb89f8f05a3","tags":[],"source":"Linux"}],"weaknesses":[],"applicability":[{"source":"Linux","statements":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.12.114"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.18.53"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"7.2"}]}]}]}],"prioritization":[]},"title":"virt: acrn: Fix irqfd use-after-free during eventfd shutdown","titleSource":"Linux","descriptionSource":"Linux","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nvirt: acrn: Fix irqfd use-after-free during eventfd shutdown\n\nacrn_irqfd_deassign() and the eventfd EPOLLHUP wakeup can race and free\nthe same struct hsm_irqfd:\n\n  CPU0                                 CPU1\n  ----                                 ----\n  eventfd_release()\n    wake_up_poll(EPOLLHUP)\n      hsm_irqfd_wakeup()\n        queue_work(&irqfd->shutdown)\n                                       acrn_irqfd_deassign()\n                                         hsm_irqfd_shutdown()\n                                           list_del_init()\n                                           eventfd_ctx_remove_wait_queue()\n                                           eventfd_ctx_put()\n                                         kfree(irqfd)\n  hsm_irqfd_shutdown_work()\n    container_of(work, ..., shutdown)\n    irqfd->vm                  <-- use-after-free\n\nThe deassign path freed the irqfd while a shutdown work item was\nalready queued by EPOLLHUP (or vice versa), so the work item could\nresurrect a dangling pointer through container_of().\n\nSwitch to the lifetime model used by KVM irqfds:\n\n - Deassign/deinit only deactivate the irqfd: remove it from vm->irqfds\n   under irqfds_lock and queue the cleanup work.\n - hsm_irqfd_shutdown_work() becomes the sole owner that unhooks the\n   eventfd waitqueue entry, drops the eventfd reference and frees the\n   irqfd.\n - A new HSM_IRQFD_FLAG_SHUTDOWN bit guarded by test_and_set_bit()\n   ensures the cleanup work is queued at most once, no matter how many\n   of {EPOLLHUP, deassign, deinit} fire concurrently.  This is safe to\n   call from the waitqueue callback, which runs with wqh->lock held and\n   IRQs disabled and therefore cannot take irqfds_lock.\n - acrn_irqfd_deassign() flushes vm->irqfd_wq before returning so the\n   eventfd is fully detached on return.  acrn_irqfd_deinit() deactivates\n   every irqfd, flushes the workqueue and only then destroys it, so no\n   path can queue_work() onto a torn-down workqueue.\n - acrn_irqfd_assign() now installs the eventfd waitqueue entry and\n   publishes the irqfd to vm->irqfds under irqfds_lock, so the irqfd is\n   never visible to deassign/deinit before its waitqueue entry is in\n   place, and any EPOLLHUP that fires in the assign window queues\n   cleanup work that blocks on irqfds_lock until publication is done.","score":7.8,"severity":"high","published":"2026-09-24T16:04:20.263Z","modified":"2026-10-30T12:36:59.771Z","withdrawn":false,"knownExploited":false,"affected":[],"products":[{"vendor":"Linux","name":"Linux","platforms":[],"versions":[{"version":"aa3b483ff1d71c50b33db154048dff9a8f08ac71","status":"affected","lessThan":"dccf23a72a6c5ec8d9eab2a7f98e186af6eaff48","versionType":"git"},{"version":"aa3b483ff1d71c50b33db154048dff9a8f08ac71","status":"affected","lessThan":"6e9e007ee1dfb54bc2d070550308077ec28dbaec","versionType":"git"},{"version":"aa3b483ff1d71c50b33db154048dff9a8f08ac71","status":"affected","lessThan":"0e1152f689847b9db2f05454775d34610c1424c2","versionType":"git"},{"version":"aa3b483ff1d71c50b33db154048dff9a8f08ac71","status":"affected","lessThan":"d8156aacfcabb81f52c20ef89094945434d08079","versionType":"git"},{"version":"aa3b483ff1d71c50b33db154048dff9a8f08ac71","status":"affected","lessThan":"666c7f9e07925aa0863348f960e09bb89f8f05a3","versionType":"git"}],"defaultStatus":"unaffected","cpes":[],"source":"Linux","url":"https://www.cve.org/CVERecord?id=CVE-2026-97478"},{"vendor":"Linux","name":"Linux","platforms":[],"versions":[{"version":"5.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.12","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"defaultStatus":"affected","cpes":[],"source":"Linux","url":"https://www.cve.org/CVERecord?id=CVE-2026-97478"}],"remediation":[],"references":["https://git.kernel.org/stable/c/dccf23a72a6c5ec8d9eab2a7f98e186af6eaff48","https://git.kernel.org/stable/c/6e9e007ee1dfb54bc2d070550308077ec28dbaec","https://git.kernel.org/stable/c/0e1152f689847b9db2f05454775d34610c1424c2","https://git.kernel.org/stable/c/d8156aacfcabb81f52c20ef89094945434d08079","https://git.kernel.org/stable/c/666c7f9e07925aa0863348f960e09bb89f8f05a3"],"sources":[{"name":"CVE","id":"CVE-2026-97478","modified":"2026-10-30T12:36:59.771Z","url":"https://www.cve.org/CVERecord?id=CVE-2026-97478"}],"assessments":[{"source":"Linux","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8}],"sourceAffected":[],"observedAt":"2026-10-30T13:56:25.694Z","kev":{"status":"not-listed","checkedAt":"2026-11-14T21:20:32.434Z"},"coverage":[{"source":"NVD","status":"not-checked"},{"source":"GHSA","status":"not-checked"},{"source":"EUVD","status":"not-checked"},{"source":"EPSS","status":"not-checked"}],"evidence":[],"aiSummary":null}