{"cve":"CVE-2025-40163","nvd":{"published":"2025-11-12T11:15:46.517","modified":"2026-10-19T21:10:00.160","status":"Deferred","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsched/deadline: Stop dl_server before CPU goes offline\n\nIBM CI tool reported kernel warning[1] when running a CPU removal\noperation through drmgr[2]. i.e \"drmgr -c cpu -r -q 1\"\n\nWARNING: CPU: 0 PID: 0 at kernel/sched/cpudeadline.c:219 cpudl_set+0x58/0x170\nNIP [c0000000002b6ed8] cpudl_set+0x58/0x170\nLR [c0000000002b7cb8] dl_server_timer+0x168/0x2a0\nCall Trace:\n[c000000002c2f8c0] init_stack+0x78c0/0x8000 (unreliable)\n[c0000000002b7cb8] dl_server_timer+0x168/0x2a0\n[c00000000034df84] __hrtimer_run_queues+0x1a4/0x390\n[c00000000034f624] hrtimer_interrupt+0x124/0x300\n[c00000000002a230] timer_interrupt+0x140/0x320\n\nGit bisects to: commit 4ae8d9aa9f9d (\"sched/deadline: Fix dl_server getting stuck\")\n\nThis happens since:\n- dl_server hrtimer gets enqueued close to cpu offline, when\n  kthread_park enqueues a fair task.\n- CPU goes offline and drmgr removes it from cpu_present_mask.\n- hrtimer fires and warning is hit.\n\nFix it by stopping the dl_server before CPU is marked dead.\n\n[1]: https://lore.kernel.org/all/8218e149-7718-4432-9312-f97297c352b9@linux.ibm.com/\n[2]: https://github.com/ibm-power-utilities/powerpc-utils/tree/next/src/drmgr\n\n[sshegde: wrote the changelog and tested it]","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/ab6c0f158508bb16d483add70b73a73f95651c33","https://git.kernel.org/stable/c/d7fd56ed5e07e053a5eea6112d61fcaded653b87","https://git.kernel.org/stable/c/ee6e44dfe6e50b4a5df853d933a96bdff5309e6e"],"products":[],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2025-40163","score":0.00199,"percentile":0.09558,"date":"2026-10-25"},"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."]}