{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.1.6-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  drm/ttm: Account for NULL and handle pages in ttm_pool_backup  Pages in ttm_pool_backup can be NULL or backup handles (ttm_backup_page_ptr_is_handle()), neither of which can be passed to set_pages_array_wb() or freed. Add a dedicated WB pass before the dma/purge loop that walks allocations using the same i += num_pages stride, skipping NULL and handle entries, and calls set_pages_array_wb() once per contiguous run of real pages. Apply the same NULL/handle guard to the dma/purge loop.  Fixes the following oops:  Oops: general protection fault, kernel NULL pointer dereference 0x0: 0000 [#1] SMP NOPTI RIP: 0010:__cpa_process_fault+0xf8/0x770 RSP: 0018:ffffc90000a87718 EFLAGS: 00010287 RAX: 0000000000000000 RBX: ffffc90000a87868 RCX: 0000000000000000 RDX: 0000000000001000 RSI: 0005088000000000 RDI: ffffffff827c5f34 RBP: 0005088000000000 R08: ffffc90000a877cb R09: ffffc90000a877d0 R10: 0000000000000000 R11: 000000000000001b R12: 000ffffffffff000 R13: ffffc90000a87868 R14: ffffc90000a87868 R15: ffff88815b882ae0 FS:  0000000000000000(0000) GS:ffff8884ec840000(0000) knlGS:0000000000000000 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f930b844000 CR3: 000000000262e003 CR4: 0000000008f70ef0 PKRU: 55555554 Call Trace:  \u003cTASK\u003e  __change_page_attr_set_clr+0x989/0xe90  ? __purge_vmap_area_lazy+0x6c/0x3a0  ? _vm_unmap_aliases+0x250/0x2a0  set_pages_array_wb+0x7f/0x120  ttm_pool_backup+0x4c9/0x5b0 [ttm]  ? dma_resv_wait_timeout+0x3b/0xf0  ttm_tt_backup+0x32/0x60 [ttm]  ttm_bo_shrink+0x66/0x110 [ttm]  xe_bo_shrink_purge+0x12b/0x1b0 [xe]  xe_bo_shrink+0xbb/0x270 [xe]  __xe_shrinker_walk+0xf7/0x160 [xe]  xe_shrinker_walk+0x9d/0xc0 [xe]  xe_shrinker_scan+0x11f/0x210 [xe]  do_shrink_slab+0x13b/0x270  shrink_slab+0xf1/0x400  shrink_node+0x352/0x8a0  balance_pgdat+0x32c/0x700  kswapd+0x205/0x2f0  ? __pfx_autoremove_wake_function+0x10/0x10  ? __pfx_kswapd+0x10/0x10  kthread+0xd1/0x110  ? __pfx_kthread+0x10/0x10  ret_from_fork+0x1b1/0x200  ? __pfx_kthread+0x10/0x10  ret_from_fork_asm+0x1a/0x30  \u003c/TASK\u003e",
  "id": "DEBIAN-CVE-2026-68239",
  "modified": "2026-09-14T16:47:50.145465942Z",
  "published": "2026-08-10T13:20:12.273Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-68239"
    }
  ],
  "upstream": [
    "CVE-2026-68239"
  ]
}