{"id":"CVE-2025-40163","summary":"sched/deadline: Stop dl_server before CPU goes offline","details":"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]","modified":"2026-04-02T12:48:18.203074Z","published":"2025-11-12T10:26:23.199Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/40xxx/CVE-2025-40163.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/ab6c0f158508bb16d483add70b73a73f95651c33"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ee6e44dfe6e50b4a5df853d933a96bdff5309e6e"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/40xxx/CVE-2025-40163.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-40163"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"4ae8d9aa9f9dc7137ea5e564d79c5aa5af1bc45c"},{"fixed":"ab6c0f158508bb16d483add70b73a73f95651c33"},{"fixed":"ee6e44dfe6e50b4a5df853d933a96bdff5309e6e"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-40163.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.17.0"},{"fixed":"6.17.5"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-40163.json"}}],"schema_version":"1.7.5"}