FKIE_CVE-2026-68090

Vulnerability from fkie_nvd - Published: 2026-08-10 12:17 - Updated: 2026-08-17 05:18
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: debugobjects: Plug race against a concurrent OOM disable syzbot reported a puzzling splat: WARNING: kernel/time/hrtimer.c:443 at stub_timer+0xa/0x20 stub_timer() is installed as timer callback function in hrtimer_fixup_assert_init(), which is invoked when debug_object_assert_init() can't find a shadow object. In that case debug objects emits a warning about it before invoking the fixup. Though the provided console log lacks this warning and instead has the following a few seconds before the splat: ODEBUG: Out of memory. ODEBUG disabled So the object was looked up in debug_object_assert_init() and the lookup failed due a concurrent out of memory situation which disabled debug objects and freed the shadow objects: debug_object_assert_init() if (!debug_objects_enabled) return; obj = alloc(); if (!obj) { // Out of memory debug_objects_enabled = false; free_objects(); obj = lookup_or_alloc(); // The lookup failed because the other side // removed the objects, so this returns // an error code as the object in question // is not statically initialized if (!IS_ERR_OR_NULL(obj)) return; if (!obj) { debug_oom(); return; } print(...) if (!debug_objects_enabled) return; fixup(...) The debug object splat is skipped because debug_objects_enabled is false, but the fixup callback is invoked unconditionally, which makes the timer disfunctional. This is only a problem in debug_object_assert_init() and debug_object_activate() as both have to handle statically initialized objects and therefore must handle the error pointer return case gracefully. All other places only handle the found/not found case and the NULL pointer return is a signal for OOM. Otherwise they get a valid shadow object. Plug the hole by checking whether debug objects are still enabled before invoking the print and fixup function in those two places.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1f4f02b336c3be125c8fcf87df73db2e0e028b8b
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/203a965bf2ab43130778d8214fb0c3c8c2d19cdf
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/23da32e88627e63e0864f59f4c63a2dc0ab851a3
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/2d5e320b7ab9b25229ac4331541964a58b5e1d29
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b81dde13cc163450dcb402dcc915ef13ba241e01
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c00164c9e7fa6145886ad666806cb5347895de5c
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d663fbf28b2eebe665bb9cf828d7d528e5a8707e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e2e255d07723c330dded8e576ce28a8d23a692ce
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "lib/debugobjects.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "2d5e320b7ab9b25229ac4331541964a58b5e1d29",
              "status": "affected",
              "version": "b84d435cc228e87951f3bbabf6cc4a5f25d5fb16",
              "versionType": "git"
            },
            {
              "lessThan": "203a965bf2ab43130778d8214fb0c3c8c2d19cdf",
              "status": "affected",
              "version": "b84d435cc228e87951f3bbabf6cc4a5f25d5fb16",
              "versionType": "git"
            },
            {
              "lessThan": "23da32e88627e63e0864f59f4c63a2dc0ab851a3",
              "status": "affected",
              "version": "b84d435cc228e87951f3bbabf6cc4a5f25d5fb16",
              "versionType": "git"
            },
            {
              "lessThan": "d663fbf28b2eebe665bb9cf828d7d528e5a8707e",
              "status": "affected",
              "version": "b84d435cc228e87951f3bbabf6cc4a5f25d5fb16",
              "versionType": "git"
            },
            {
              "lessThan": "e2e255d07723c330dded8e576ce28a8d23a692ce",
              "status": "affected",
              "version": "b84d435cc228e87951f3bbabf6cc4a5f25d5fb16",
              "versionType": "git"
            },
            {
              "lessThan": "c00164c9e7fa6145886ad666806cb5347895de5c",
              "status": "affected",
              "version": "b84d435cc228e87951f3bbabf6cc4a5f25d5fb16",
              "versionType": "git"
            },
            {
              "lessThan": "1f4f02b336c3be125c8fcf87df73db2e0e028b8b",
              "status": "affected",
              "version": "b84d435cc228e87951f3bbabf6cc4a5f25d5fb16",
              "versionType": "git"
            },
            {
              "lessThan": "b81dde13cc163450dcb402dcc915ef13ba241e01",
              "status": "affected",
              "version": "b84d435cc228e87951f3bbabf6cc4a5f25d5fb16",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "lib/debugobjects.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.3"
            },
            {
              "lessThan": "3.3",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.261",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.212",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.178",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.96",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndebugobjects: Plug race against a concurrent OOM disable\n\nsyzbot reported a puzzling splat:\n\n   WARNING: kernel/time/hrtimer.c:443 at stub_timer+0xa/0x20\n\nstub_timer() is installed as timer callback function in\nhrtimer_fixup_assert_init(), which is invoked when\ndebug_object_assert_init() can\u0027t find a shadow object. In that case debug\nobjects emits a warning about it before invoking the fixup.\n\nThough the provided console log lacks this warning and instead has the\nfollowing a few seconds before the splat:\n\n     ODEBUG: Out of memory. ODEBUG disabled\n\nSo the object was looked up in debug_object_assert_init() and the lookup\nfailed due a concurrent out of memory situation which disabled debug\nobjects and freed the shadow objects:\n\ndebug_object_assert_init()\n        if (!debug_objects_enabled)\n        \treturn;                         obj = alloc();\n                \t\t\t\tif (!obj) {\n\t\t\t\t\t\t\t// Out of memory\n                                                \tdebug_objects_enabled = false;\n                                                        free_objects();\n        obj = lookup_or_alloc();\n\n        // The lookup failed because the other side\n        // removed the objects, so this returns\n        // an error code as the object in question\n        // is not statically initialized\n\n\tif (!IS_ERR_OR_NULL(obj))\n        \treturn;\n        if (!obj) {\n        \tdebug_oom();\n                return;\n        }\n\n        print(...)\n           if (!debug_objects_enabled)\n                return;\n\n        fixup(...)\n\nThe debug object splat is skipped because debug_objects_enabled is false,\nbut the fixup callback is invoked unconditionally, which makes the timer\ndisfunctional.\n\nThis is only a problem in debug_object_assert_init() and\ndebug_object_activate() as both have to handle statically initialized\nobjects and therefore must handle the error pointer return case\ngracefully. All other places only handle the found/not found case and the\nNULL pointer return is a signal for OOM. Otherwise they get a valid shadow\nobject.\n\nPlug the hole by checking whether debug objects are still enabled before\ninvoking the print and fixup function in those two places."
    }
  ],
  "id": "CVE-2026-68090",
  "lastModified": "2026-08-17T05:18:08.173",
  "metrics": {},
  "published": "2026-08-10T12:17:21.717",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1f4f02b336c3be125c8fcf87df73db2e0e028b8b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/203a965bf2ab43130778d8214fb0c3c8c2d19cdf"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/23da32e88627e63e0864f59f4c63a2dc0ab851a3"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2d5e320b7ab9b25229ac4331541964a58b5e1d29"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b81dde13cc163450dcb402dcc915ef13ba241e01"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c00164c9e7fa6145886ad666806cb5347895de5c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d663fbf28b2eebe665bb9cf828d7d528e5a8707e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e2e255d07723c330dded8e576ce28a8d23a692ce"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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