{"resultsPerPage":1,"startIndex":0,"totalResults":1,"format":"NVD_CVE","version":"2.0","timestamp":"2026-04-20T00:50:29.848","vulnerabilities":[{"cve":{"id":"CVE-2025-68810","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","published":"2026-01-13T16:16:03.190","lastModified":"2026-04-15T00:35:42.020","vulnStatus":"Deferred","cveTags":[],"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"},{"lang":"es","value":"En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nKVM: No permitir la alternancia de KVM_MEM_GUEST_MEMFD en un memslot existente\n\nRechazar los intentos de deshabilitar KVM_MEM_GUEST_MEMFD en un memslot que fue creado inicialmente con una vinculación guest_memfd, ya que KVM no soporta la alternancia de KVM_MEM_GUEST_MEMFD en memslots existentes. KVM impide habilitar KVM_MEM_GUEST_MEMFD, pero no impide borrar el indicador.\n\nLa falta de rechazo del nuevo memslot resulta en un uso después de liberación debido a que KVM no se desvincula de la instancia guest_memfd. La desvinculación en un cambio de FLAGS_ONLY es bastante sencilla, y puede/será realizada como una medida de endurecimiento (en anticipación de que KVM soporte el registro de cambios (dirty logging) en guest_memfd en algún momento), pero corregir el uso después de liberación solo abordaría el síntoma inmediato.\n\n  ==================================================================\n  ERROR: KASAN: uso después de liberación de slab en kvm_gmem_release+0x362/0x400 [kvm]\n  Escritura de tamaño 8 en la dirección ffff8881111ae908 por la tarea repro/745\n\n  CPU: 7 UID: 1000 PID: 745 Comm: repro No contaminado 6.18.0-rc6-115d5de2eef3-next-kasan #3 NINGUNO\n  Nombre del hardware: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015\n  Traza de llamada:\n   \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   \n\n  Asignado por la tarea 745 en la CPU 6 a las 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  Liberado por la tarea 745 en la CPU 6 a las 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":{},"references":[{"url":"https://git.kernel.org/stable/c/89dbbe6ff323fc34659621a577fe0af913f47386","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/9935df5333aa503a18de5071f53762b65c783c4c","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/cb51bef465d8ec60a968507330e01020e35dc127","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}]}}]}