{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:12",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:13",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  vfio/pci: clear vdev-\u003emsi_perm after freeing it on init failure  vfio_msi_cap_len() lazily allocates the per-device MSI permission table:  \tvdev-\u003emsi_perm = kmalloc_obj(struct perm_bits, GFP_KERNEL_ACCOUNT); \tif (!vdev-\u003emsi_perm) \t\treturn -ENOMEM;  \tret = init_pci_cap_msi_perm(vdev-\u003emsi_perm, len, flags); \tif (ret) { \t\tkfree(vdev-\u003emsi_perm); \t\treturn ret;\t\t/* vdev-\u003emsi_perm left dangling */ \t}  When init_pci_cap_msi_perm() -\u003e alloc_perm_bits() fails with -ENOMEM, the error path frees vdev-\u003emsi_perm but leaves the freed pointer stored in it. vdev-\u003emsi_perm is not re-zeroed later because struct vfio_pci_core_device is per-device and persists across open/close cycles, and the vfio_config_init() error path returns without calling vfio_config_free(). So the dangling pointer outlives the failed open.  That leads to two use-after-frees on the same device:  1. Reuse. The next vfio_config_init() sees the stale pointer at    \"if (vdev-\u003emsi_perm) return len;\" and reuses the freed object. MSI    config accesses in vfio_pci_config_rw_single() then dereference and    call the freed perm-\u003ereadfn / perm-\u003ewritefn function pointers.  2. Double free. A later vfio_config_free() runs free_perm_bits() and    kfree() on the already-freed object.  Fix it by NULLing vdev-\u003emsi_perm after the kfree(), matching the NULL-after-free discipline already used in free_perm_bits() and vfio_config_free().    BUG: KASAN: slab-use-after-free in vfio_pci_config_rw_single (drivers/vfio/pci/vfio_pci_config.c:1961)   Read of size 8 at addr ffff88800fcc88d0 by task exploit/143   Call Trace:    ...    kasan_report (mm/kasan/report.c:595)    vfio_pci_config_rw_single (drivers/vfio/pci/vfio_pci_config.c:1961)    vfio_pci_config_rw (drivers/vfio/pci/vfio_pci_config.c:1986)    vfio_pci_rw (drivers/vfio/pci/vfio_pci_core.c:1599)    vfs_read (fs/read_write.c:572)    __x64_sys_pread64 (fs/read_write.c:764)    do_syscall_64 (arch/x86/entry/syscall_64.c:94)    ...  Followed on device close by a double free of the same object:    Oops: general protection fault, probably for non-canonical address     0x1f63e0e8000008: 0000 [#1] SMP KASAN NOPTI   RIP: 0010:kfree (mm/slub.c:6711)   Call Trace:    vfio_config_free (drivers/vfio/pci/vfio_pci_config.c:1861)    vfio_pci_core_disable (drivers/vfio/pci/vfio_pci_core.c:685)    vfio_pci_core_close_device (drivers/vfio/pci/vfio_pci_core.c:777)    vfio_df_close (drivers/vfio/vfio_main.c:602)    vfio_device_fops_release (drivers/vfio/vfio_main.c:648)    __fput (fs/file_table.c:512)    __x64_sys_close (fs/open.c:1496)    do_syscall_64 (arch/x86/entry/syscall_64.c:94)    ...   Kernel panic - not syncing: Fatal exception",
  "id": "DEBIAN-CVE-2026-89777",
  "modified": "2026-09-17T04:47:39.858755486Z",
  "published": "2026-09-16T09:17:08.073Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-89777"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "upstream": [
    "CVE-2026-89777"
  ]
}