{"cve":"CVE-2026-68090","nvd":{"published":"2026-08-10T12:17:21.717","modified":"2026-08-17T05:18:08.173","status":"Received","description":"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't 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.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/1f4f02b336c3be125c8fcf87df73db2e0e028b8b","https://git.kernel.org/stable/c/203a965bf2ab43130778d8214fb0c3c8c2d19cdf","https://git.kernel.org/stable/c/23da32e88627e63e0864f59f4c63a2dc0ab851a3","https://git.kernel.org/stable/c/2d5e320b7ab9b25229ac4331541964a58b5e1d29","https://git.kernel.org/stable/c/b81dde13cc163450dcb402dcc915ef13ba241e01"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:47:54.990491175+00:00"},"epss":{"cve":"CVE-2026-68090","score":0.00177,"percentile":0.07185,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}