{"api_version":"1","generated_at":"2026-08-05T05:17:40+00:00","cve":"CVE-2025-68810","urls":{"html":"https://cve.report/CVE-2025-68810","api":"https://cve.report/api/cve/CVE-2025-68810.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2025-68810","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-68810"},"summary":{"title":"KVM: Disallow toggling KVM_MEM_GUEST_MEMFD on an existing memslot","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: Disallow toggling KVM_MEM_GUEST_MEMFD on an existing memslot\n\nReject attempts to disable KVM_MEM_GUEST_MEMFD on a memslot that was\ninitially created with a guest_memfd binding, as KVM doesn't support\ntoggling KVM_MEM_GUEST_MEMFD on existing memslots.  KVM prevents enabling\nKVM_MEM_GUEST_MEMFD, but doesn't prevent clearing the flag.\n\nFailure to reject the new memslot results in a use-after-free due to KVM\nnot unbinding from the guest_memfd instance.  Unbinding on a FLAGS_ONLY\nchange is easy enough, and can/will be done as a hardening measure (in\nanticipation of KVM supporting dirty logging on guest_memfd at some point),\nbut fixing the use-after-free would only address the immediate symptom.\n\n  ==================================================================\n  BUG: KASAN: slab-use-after-free in kvm_gmem_release+0x362/0x400 [kvm]\n  Write of size 8 at addr ffff8881111ae908 by task repro/745\n\n  CPU: 7 UID: 1000 PID: 745 Comm: repro Not tainted 6.18.0-rc6-115d5de2eef3-next-kasan #3 NONE\n  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015\n  Call Trace:\n   <TASK>\n   dump_stack_lvl+0x51/0x60\n   print_report+0xcb/0x5c0\n   kasan_report+0xb4/0xe0\n   kvm_gmem_release+0x362/0x400 [kvm]\n   __fput+0x2fa/0x9d0\n   task_work_run+0x12c/0x200\n   do_exit+0x6ae/0x2100\n   do_group_exit+0xa8/0x230\n   __x64_sys_exit_group+0x3a/0x50\n   x64_sys_call+0x737/0x740\n   do_syscall_64+0x5b/0x900\n   entry_SYSCALL_64_after_hwframe+0x4b/0x53\n  RIP: 0033:0x7f581f2eac31\n   </TASK>\n\n  Allocated by task 745 on cpu 6 at 9.746971s:\n   kasan_save_stack+0x20/0x40\n   kasan_save_track+0x13/0x50\n   __kasan_kmalloc+0x77/0x90\n   kvm_set_memory_region.part.0+0x652/0x1110 [kvm]\n   kvm_vm_ioctl+0x14b0/0x3290 [kvm]\n   __x64_sys_ioctl+0x129/0x1a0\n   do_syscall_64+0x5b/0x900\n   entry_SYSCALL_64_after_hwframe+0x4b/0x53\n\n  Freed by task 745 on cpu 6 at 9.747467s:\n   kasan_save_stack+0x20/0x40\n   kasan_save_track+0x13/0x50\n   __kasan_save_free_info+0x37/0x50\n   __kasan_slab_free+0x3b/0x60\n   kfree+0xf5/0x440\n   kvm_set_memslot+0x3c2/0x1160 [kvm]\n   kvm_set_memory_region.part.0+0x86a/0x1110 [kvm]\n   kvm_vm_ioctl+0x14b0/0x3290 [kvm]\n   __x64_sys_ioctl+0x129/0x1a0\n   do_syscall_64+0x5b/0x900\n   entry_SYSCALL_64_after_hwframe+0x4b/0x53","state":"PUBLISHED","assigner":"Linux","published_at":"2026-01-13 16:16:03","updated_at":"2026-07-30 06:24:46"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/9935df5333aa503a18de5071f53762b65c783c4c","name":"https://git.kernel.org/stable/c/9935df5333aa503a18de5071f53762b65c783c4c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/89dbbe6ff323fc34659621a577fe0af913f47386","name":"https://git.kernel.org/stable/c/89dbbe6ff323fc34659621a577fe0af913f47386","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/cb51bef465d8ec60a968507330e01020e35dc127","name":"https://git.kernel.org/stable/c/cb51bef465d8ec60a968507330e01020e35dc127","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2025-68810","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-68810","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a7800aa80ea4d5356b8474c2302812e9d4926fa6 89dbbe6ff323fc34659621a577fe0af913f47386 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a7800aa80ea4d5356b8474c2302812e9d4926fa6 cb51bef465d8ec60a968507330e01020e35dc127 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a7800aa80ea4d5356b8474c2302812e9d4926fa6 9935df5333aa503a18de5071f53762b65c783c4c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.8","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.8 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.64 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.3 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.19 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2025","cve_id":"68810","cve":"CVE-2025-68810","epss":"0.001240000","percentile":"0.025100000","score_date":"2026-08-01","updated_at":"2026-08-02 00:11:14"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["virt/kvm/kvm_main.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"89dbbe6ff323fc34659621a577fe0af913f47386","status":"affected","version":"a7800aa80ea4d5356b8474c2302812e9d4926fa6","versionType":"git"},{"lessThan":"cb51bef465d8ec60a968507330e01020e35dc127","status":"affected","version":"a7800aa80ea4d5356b8474c2302812e9d4926fa6","versionType":"git"},{"lessThan":"9935df5333aa503a18de5071f53762b65c783c4c","status":"affected","version":"a7800aa80ea4d5356b8474c2302812e9d4926fa6","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["virt/kvm/kvm_main.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.8"},{"lessThan":"6.8","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.64","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.3","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"6.19","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.64","versionStartIncluding":"6.8","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.3","versionStartIncluding":"6.8","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.19","versionStartIncluding":"6.8","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: Disallow toggling KVM_MEM_GUEST_MEMFD on an existing memslot\n\nReject attempts to disable KVM_MEM_GUEST_MEMFD on a memslot that was\ninitially created with a guest_memfd binding, as KVM doesn't support\ntoggling KVM_MEM_GUEST_MEMFD on existing memslots.  KVM prevents enabling\nKVM_MEM_GUEST_MEMFD, but doesn't prevent clearing the flag.\n\nFailure to reject the new memslot results in a use-after-free due to KVM\nnot unbinding from the guest_memfd instance.  Unbinding on a FLAGS_ONLY\nchange is easy enough, and can/will be done as a hardening measure (in\nanticipation of KVM supporting dirty logging on guest_memfd at some point),\nbut fixing the use-after-free would only address the immediate symptom.\n\n  ==================================================================\n  BUG: KASAN: slab-use-after-free in kvm_gmem_release+0x362/0x400 [kvm]\n  Write of size 8 at addr ffff8881111ae908 by task repro/745\n\n  CPU: 7 UID: 1000 PID: 745 Comm: repro Not tainted 6.18.0-rc6-115d5de2eef3-next-kasan #3 NONE\n  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015\n  Call Trace:\n   <TASK>\n   dump_stack_lvl+0x51/0x60\n   print_report+0xcb/0x5c0\n   kasan_report+0xb4/0xe0\n   kvm_gmem_release+0x362/0x400 [kvm]\n   __fput+0x2fa/0x9d0\n   task_work_run+0x12c/0x200\n   do_exit+0x6ae/0x2100\n   do_group_exit+0xa8/0x230\n   __x64_sys_exit_group+0x3a/0x50\n   x64_sys_call+0x737/0x740\n   do_syscall_64+0x5b/0x900\n   entry_SYSCALL_64_after_hwframe+0x4b/0x53\n  RIP: 0033:0x7f581f2eac31\n   </TASK>\n\n  Allocated by task 745 on cpu 6 at 9.746971s:\n   kasan_save_stack+0x20/0x40\n   kasan_save_track+0x13/0x50\n   __kasan_kmalloc+0x77/0x90\n   kvm_set_memory_region.part.0+0x652/0x1110 [kvm]\n   kvm_vm_ioctl+0x14b0/0x3290 [kvm]\n   __x64_sys_ioctl+0x129/0x1a0\n   do_syscall_64+0x5b/0x900\n   entry_SYSCALL_64_after_hwframe+0x4b/0x53\n\n  Freed by task 745 on cpu 6 at 9.747467s:\n   kasan_save_stack+0x20/0x40\n   kasan_save_track+0x13/0x50\n   __kasan_save_free_info+0x37/0x50\n   __kasan_slab_free+0x3b/0x60\n   kfree+0xf5/0x440\n   kvm_set_memslot+0x3c2/0x1160 [kvm]\n   kvm_set_memory_region.part.0+0x86a/0x1110 [kvm]\n   kvm_vm_ioctl+0x14b0/0x3290 [kvm]\n   __x64_sys_ioctl+0x129/0x1a0\n   do_syscall_64+0x5b/0x900\n   entry_SYSCALL_64_after_hwframe+0x4b/0x53"}],"metrics":[{"cvssV3_1":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"providerMetadata":{"dateUpdated":"2026-07-30T06:04:51.906Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/89dbbe6ff323fc34659621a577fe0af913f47386"},{"url":"https://git.kernel.org/stable/c/cb51bef465d8ec60a968507330e01020e35dc127"},{"url":"https://git.kernel.org/stable/c/9935df5333aa503a18de5071f53762b65c783c4c"}],"title":"KVM: Disallow toggling KVM_MEM_GUEST_MEMFD on an existing memslot","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2025-68810","datePublished":"2026-01-13T15:29:16.475Z","dateReserved":"2025-12-24T10:30:51.047Z","dateUpdated":"2026-07-30T06:04:51.906Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-01-13 16:16:03","lastModifiedDate":"2026-07-30 06:24:46","problem_types":[],"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:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2025","CveId":"68810","Ordinal":"1","Title":"KVM: Disallow toggling KVM_MEM_GUEST_MEMFD on an existing memslo","CVE":"CVE-2025-68810","Year":"2025"},"notes":[{"CveYear":"2025","CveId":"68810","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: Disallow toggling KVM_MEM_GUEST_MEMFD on an existing memslot\n\nReject attempts to disable KVM_MEM_GUEST_MEMFD on a memslot that was\ninitially created with a guest_memfd binding, as KVM doesn't support\ntoggling KVM_MEM_GUEST_MEMFD on existing memslots.  KVM prevents enabling\nKVM_MEM_GUEST_MEMFD, but doesn't prevent clearing the flag.\n\nFailure to reject the new memslot results in a use-after-free due to KVM\nnot unbinding from the guest_memfd instance.  Unbinding on a FLAGS_ONLY\nchange is easy enough, and can/will be done as a hardening measure (in\nanticipation of KVM supporting dirty logging on guest_memfd at some point),\nbut fixing the use-after-free would only address the immediate symptom.\n\n  ==================================================================\n  BUG: KASAN: slab-use-after-free in kvm_gmem_release+0x362/0x400 [kvm]\n  Write of size 8 at addr ffff8881111ae908 by task repro/745\n\n  CPU: 7 UID: 1000 PID: 745 Comm: repro Not tainted 6.18.0-rc6-115d5de2eef3-next-kasan #3 NONE\n  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015\n  Call Trace:\n   <TASK>\n   dump_stack_lvl+0x51/0x60\n   print_report+0xcb/0x5c0\n   kasan_report+0xb4/0xe0\n   kvm_gmem_release+0x362/0x400 [kvm]\n   __fput+0x2fa/0x9d0\n   task_work_run+0x12c/0x200\n   do_exit+0x6ae/0x2100\n   do_group_exit+0xa8/0x230\n   __x64_sys_exit_group+0x3a/0x50\n   x64_sys_call+0x737/0x740\n   do_syscall_64+0x5b/0x900\n   entry_SYSCALL_64_after_hwframe+0x4b/0x53\n  RIP: 0033:0x7f581f2eac31\n   </TASK>\n\n  Allocated by task 745 on cpu 6 at 9.746971s:\n   kasan_save_stack+0x20/0x40\n   kasan_save_track+0x13/0x50\n   __kasan_kmalloc+0x77/0x90\n   kvm_set_memory_region.part.0+0x652/0x1110 [kvm]\n   kvm_vm_ioctl+0x14b0/0x3290 [kvm]\n   __x64_sys_ioctl+0x129/0x1a0\n   do_syscall_64+0x5b/0x900\n   entry_SYSCALL_64_after_hwframe+0x4b/0x53\n\n  Freed by task 745 on cpu 6 at 9.747467s:\n   kasan_save_stack+0x20/0x40\n   kasan_save_track+0x13/0x50\n   __kasan_save_free_info+0x37/0x50\n   __kasan_slab_free+0x3b/0x60\n   kfree+0xf5/0x440\n   kvm_set_memslot+0x3c2/0x1160 [kvm]\n   kvm_set_memory_region.part.0+0x86a/0x1110 [kvm]\n   kvm_vm_ioctl+0x14b0/0x3290 [kvm]\n   __x64_sys_ioctl+0x129/0x1a0\n   do_syscall_64+0x5b/0x900\n   entry_SYSCALL_64_after_hwframe+0x4b/0x53","Type":"Description","Title":"KVM: Disallow toggling KVM_MEM_GUEST_MEMFD on an existing memslo"}]}}}