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CVE-2026-99007

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: drm/fb-helper: defer setup when fbdev_probe() fails, not just on -EAGAIN __drm_fb_helper_initial_config_and_unlock() calls drm_client_modeset_probe() first, which already fills in each mode_set->mode/num_connectors for every connected output, and only afterwards calls drm_fb_helper_single_fb_probe() to create fb_helper->fb and wire it into those mode_sets via drm_setup_crtcs_fb(). If drm_fb_helper_single_fb_probe() fails with anything other than -EAGAIN (e.g. dev->driver->fbdev_probe() itself fails), the function bails out before drm_setup_crtcs_fb() runs and before setting fb_helper->deferred_setup. The client is left with mode_sets that have a mode and connectors but mode_set->fb == NULL, and nothing marks this fb_helper as needing a retry. __drm_fb_helper_restore_fbdev_mode_unlocked() only skips committing when fb_helper->deferred_setup is set, so a later .restore() call (drm_lastclose() on process exit, in this report) commits the stale mode_set through drm_client_modeset_commit() -> drm_client_modeset_commit_atomic() -> __drm_atomic_helper_set_config(), which hits WARN_ON(!set->fb). Mark fb_helper->deferred_setup on any drm_fb_helper_single_fb_probe() failure, not just -EAGAIN, so restore keeps skipping the commit until a later hotplug event successfully re-probes and re-populates mode_set->fb. The real error code is still returned to the caller unchanged.

Severity
Not scored
CVSS score
Not available
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-10-23 13:17:23.157000
Last modified
2026-10-30 13:21:35.327000
View original CVE JSON
{
  "id": "CVE-2026-99007",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-23T13:17:23.157",
  "lastModified": "2026-10-30T13:21:35.327",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/fb-helper: defer setup when fbdev_probe() fails, not just on -EAGAIN\n\n__drm_fb_helper_initial_config_and_unlock() calls\ndrm_client_modeset_probe() first, which already fills in each\nmode_set->mode/num_connectors for every connected output, and only\nafterwards calls drm_fb_helper_single_fb_probe() to create\nfb_helper->fb and wire it into those mode_sets via\ndrm_setup_crtcs_fb().\n\nIf drm_fb_helper_single_fb_probe() fails with anything other than\n-EAGAIN (e.g. dev->driver->fbdev_probe() itself fails), the function\nbails out before drm_setup_crtcs_fb() runs and before setting\nfb_helper->deferred_setup. The client is left with mode_sets that\nhave a mode and connectors but mode_set->fb == NULL, and nothing\nmarks this fb_helper as needing a retry.\n\n__drm_fb_helper_restore_fbdev_mode_unlocked() only skips committing\nwhen fb_helper->deferred_setup is set, so a later .restore() call\n(drm_lastclose() on process exit, in this report) commits the stale\nmode_set through drm_client_modeset_commit() ->\ndrm_client_modeset_commit_atomic() -> __drm_atomic_helper_set_config(),\nwhich hits WARN_ON(!set->fb).\n\nMark fb_helper->deferred_setup on any drm_fb_helper_single_fb_probe()\nfailure, not just -EAGAIN, so restore keeps skipping the commit until\na later hotplug event successfully re-probes and re-populates\nmode_set->fb. The real error code is still returned to the caller\nunchanged."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/gpu/drm/drm_fb_helper.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "ca91a2758fcef6635626993557dd51cfbb6dd134",
              "lessThan": "423c871a586cff8b29f48db00e3c45c21d0e8121",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "ca91a2758fcef6635626993557dd51cfbb6dd134",
              "lessThan": "e5f8f6e0f0a18c77c04b757d72319d897a0b4bc1",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "ca91a2758fcef6635626993557dd51cfbb6dd134",
              "lessThan": "9124411cb91b129ff3ffb0d723ecba7a5bf893f9",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "ca91a2758fcef6635626993557dd51cfbb6dd134",
              "lessThan": "4a2006c675758f0c765b36fec6b49d17e89159cf",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "ca91a2758fcef6635626993557dd51cfbb6dd134",
              "lessThan": "3b303696f61461b3569019d7fcac6a646652b2b4",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "ca91a2758fcef6635626993557dd51cfbb6dd134",
              "lessThan": "4e7b508c7c60dec7a86b7eb2a1b7e6d174afa457",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "ca91a2758fcef6635626993557dd51cfbb6dd134",
              "lessThan": "d510ed273854177f0a3ed330145858b2fe667f81",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "ca91a2758fcef6635626993557dd51cfbb6dd134",
              "lessThan": "755c94d178b7e972bb766199d34e4ba4f63a89eb",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/gpu/drm/drm_fb_helper.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "4.14",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "4.14",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.10.273",
              "lessThanOrEqual": "5.10.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.15.224",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.191",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.160",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.113",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.57",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.11",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {},
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/3b303696f61461b3569019d7fcac6a646652b2b4",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/423c871a586cff8b29f48db00e3c45c21d0e8121",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/4a2006c675758f0c765b36fec6b49d17e89159cf",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/4e7b508c7c60dec7a86b7eb2a1b7e6d174afa457",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/755c94d178b7e972bb766199d34e4ba4f63a89eb",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/9124411cb91b129ff3ffb0d723ecba7a5bf893f9",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/d510ed273854177f0a3ed330145858b2fe667f81",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e5f8f6e0f0a18c77c04b757d72319d897a0b4bc1",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}