{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.2.9-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  drm/amdkfd: fix use-after-free and multi-container gap in kfd_dev_mapping  kfd_dev_mapping caches the address_space of the first /dev/kfd opener so that the GPU reset path can call unmap_mapping_range() to zap all userspace mappings of doorbell and MMIO ranges.  This design has two bugs that both manifest under SRIOV with multiple containers:  1. Use-after-free / rwsem deadlock.  The cached pointer refers to an    inode owned by the first opener's container.  When that container    exits and its inode is released, kfd_dev_mapping becomes a dangling    pointer.  A subsequent GPU reset dereferences it inside    unmap_mapping_range(), which takes i_mmap_rwsem on the freed inode,    causing a hard hang observable as an uninterruptible rwsem wait.  2. Multi-container gap.  Only the first opener's address_space is cached;    VMAs created by later openers live in a different address_space and    are never reached by unmap_mapping_range().  After a GPU reset those    stale mappings keep doorbell and MMIO pages accessible to guest    userspace with no GPU behind them, risking PCIe transaction timeouts    and NMI panics.  Fix both bugs with the same approach used by DRM core (drm_drv.c): create a private pseudo-filesystem at module init time and allocate one anonymous inode from it.  In kfd_open() redirect every opener's file-\u003ef_mapping to that inode's address_space.  The inode is module-owned, lives exactly as long as the amdgpu module, and collects VMAs from all openers in one address_space.  A single unmap_mapping_range() call in the reset path then correctly reaches every container's mappings with no dangling pointer risk.  The hang manifests as an NMI backtrace on the GPU reset workqueue stuck spinning in rwsem_down_read_slowpath() with a corrupted i_mmap_rwsem:    Workqueue: amdgpu-reset-dev xgpu_ai_mailbox_flr_work [amdgpu]   Call Trace:    \u003cTASK\u003e    kvm_wait+0x1f/0x40    __pv_queued_spin_lock_slowpath+0x31d/0x3a0    _raw_spin_lock_irq+0x51/0x80    rwsem_down_read_slowpath+0xb3/0x550    down_read+0x48/0xd0    unmap_mapping_range+0x71/0x140    kfd_dev_unmap_mapping_range+0x5b/0x140 [amdgpu]    amdgpu_amdkfd_clear_kfd_mapping+0xd8/0x190 [amdgpu]    amdgpu_device_gpu_recover+0x232/0x450 [amdgpu]    xgpu_ai_mailbox_flr_work+0xb5/0xc0 [amdgpu]    process_one_work+0x18e/0x3e0    worker_thread+0x2e3/0x420    kthread+0x10a/0x230  (cherry picked from commit 1128b4a52de1572e87431de837fd9850cb99542c)",
  "id": "DEBIAN-CVE-2026-98520",
  "modified": "2026-10-19T04:47:42.647238512Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-98520"
    }
  ],
  "upstream": [
    "CVE-2026-98520"
  ]
}