{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "7f5535fcbba2ce7f1908ee7e5c350032a4b1e9d0"
            },
            {
              "fixed": "11edd5b6735d2e1069ddce672b1836713647f7fb"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "5d08c44e47b9d41366714552bdd374ac4b595591"
            },
            {
              "fixed": "fcbedba553a9c430079ee225df2dc7ab556a2f83"
            },
            {
              "fixed": "a69c4b678db808c0d89abb8cedeaaac38d1ef182"
            },
            {
              "fixed": "1fca688e9443003e33cf30453e7a7560367656c9"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "6.12.19"
            },
            {
              "fixed": "6.12.112"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.12.112"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.55"
            },
            {
              "fixed": "7.2.9"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98523.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/client: fix restore of partially initialized client\n\nI got a null-ptr-deref report when closing a DRM file descriptor:\n\nWARNING: drivers/gpu/drm/drm_atomic.c:2031 at\n__drm_atomic_helper_set_config+0x18e/0x1b0 [drm]\n\nCall Trace:\ndrm_client_modeset_commit_atomic+0x16b/0x220 [drm]\ndrm_client_modeset_commit_locked+0x56/0x160 [drm]\ndrm_client_modeset_commit+0x21/0x40 [drm]\n__drm_fb_helper_restore_fbdev_mode_unlocked.part.0+0x7b/0x80\ndrm_fbdev_client_restore+0xe/0x20 [drm_client_lib]\ndrm_client_dev_restore+0x9f/0xc0 [drm]\ndrm_release+0xc5/0xe0 [drm]\n\nThe warning is followed by a NULL pointer dereference:\n\nBUG: kernel NULL pointer dereference, address: 0000000000000008\n\nRIP:\n__drm_fb_helper_restore_fbdev_mode_unlocked.part.0+0x41/0x80\n[drm_kms_helper]\n\nCall Trace:\ndrm_fbdev_client_restore+0xe/0x20 [drm_client_lib]\ndrm_client_dev_restore+0x9f/0xc0 [drm]\ndrm_release+0xc5/0xe0 [drm]\n__fput+0xdc/0x2b0\n__x64_sys_close+0x39/0x80\ndo_syscall_64+0x8d/0x460\nentry_SYSCALL_64_after_hwframe+0x76/0x7e\n\ndrm_client_register() adds the DRM client to the device client list\nbefore invoking the initial hotplug callback. If the hotplug callback\nfails, the client remains registered.\n\nFor the fbdev client, a failure during drm_fb_helper_initial_config()\ncauses the partially initialized fbdev helper to be cleaned up.\ndrm_fb_helper_fini() releases fb_helper-\u003einfo and leaves it NULL.\n\nThe fbdev client therefore remains registered even though there is no\nfully initialized framebuffer device.\n\nLater, when userspace closes the DRM file descriptor, drm_release()\ncan invoke the restore callbacks of registered DRM clients:\n\ndrm_release()\ndrm_client_dev_restore()\ndrm_fbdev_client_restore()\ndrm_fb_helper_restore_fbdev_mode_unlocked()\n\ndrm_fbdev_client_restore() currently restores the fbdev state\nunconditionally. For a partially initialized fbdev client this can\nsubmit an incomplete modeset state and subsequently access fbdev\nstate which has not been initialized, resulting in the warning and\nNULL pointer dereference above.\n\ndrm_fbdev_client_unregister() already uses fb_helper-\u003einfo to\ndistinguish a fully probed framebuffer device from a partially\ninitialized client.\n\nUse the same condition in drm_fbdev_client_restore() and skip restore\nif no framebuffer device has been successfully initialized.",
  "id": "CVE-2026-98523",
  "modified": "2026-10-20T02:30:47.694623789Z",
  "published": "2026-10-18T15:17:40.598Z",
  "references": [
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/11edd5b6735d2e1069ddce672b1836713647f7fb"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1fca688e9443003e33cf30453e7a7560367656c9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a69c4b678db808c0d89abb8cedeaaac38d1ef182"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fcbedba553a9c430079ee225df2dc7ab556a2f83"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98523.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98523"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "drm/client: fix restore of partially initialized client"
}