{"id":"CVE-2025-40163","state":"PUBLISHED","title":"sched/deadline: Stop dl_server before CPU goes offline","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]","publishedAt":"2025-11-12T10:26:23.199Z","updatedAt":"2026-06-01T16:05:34.972Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"030167dcadf50a9f9dac4de6fa4c34f4f7afeed7","status":"affected","lessThan":"d7fd56ed5e07e053a5eea6112d61fcaded653b87","versionType":"git"},{"version":"4ae8d9aa9f9dc7137ea5e564d79c5aa5af1bc45c","status":"affected","lessThan":"ab6c0f158508bb16d483add70b73a73f95651c33","versionType":"git"},{"version":"4ae8d9aa9f9dc7137ea5e564d79c5aa5af1bc45c","status":"affected","lessThan":"ee6e44dfe6e50b4a5df853d933a96bdff5309e6e","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/sched/core.c","kernel/sched/deadline.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.17","versionType":"semver"},{"version":"6.17.5","status":"unaffected","lessThanOrEqual":"6.17.*","versionType":"semver"},{"version":"6.18","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/sched/core.c","kernel/sched/deadline.c"]}],"references":["https://git.kernel.org/stable/c/d7fd56ed5e07e053a5eea6112d61fcaded653b87","https://git.kernel.org/stable/c/ab6c0f158508bb16d483add70b73a73f95651c33","https://git.kernel.org/stable/c/ee6e44dfe6e50b4a5df853d933a96bdff5309e6e"],"weaknesses":[],"ingestedAt":"2026-10-29T20:09:09.358Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/40xxx/CVE-2025-40163.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-40163","state":"PUBLISHED","datePublished":"2025-11-12T10:26:23.199Z","dateUpdated":"2026-06-01T16:05:34.972Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-04-16T07:20:57.176Z"},"containers":{"cna":{"title":"sched/deadline: Stop dl_server before CPU goes offline","descriptions":[{"lang":"en","value":"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]"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"030167dcadf50a9f9dac4de6fa4c34f4f7afeed7","status":"affected","lessThan":"d7fd56ed5e07e053a5eea6112d61fcaded653b87","versionType":"git"},{"version":"4ae8d9aa9f9dc7137ea5e564d79c5aa5af1bc45c","status":"affected","lessThan":"ab6c0f158508bb16d483add70b73a73f95651c33","versionType":"git"},{"version":"4ae8d9aa9f9dc7137ea5e564d79c5aa5af1bc45c","status":"affected","lessThan":"ee6e44dfe6e50b4a5df853d933a96bdff5309e6e","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/sched/core.c","kernel/sched/deadline.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.17","versionType":"semver"},{"version":"6.17.5","status":"unaffected","lessThanOrEqual":"6.17.*","versionType":"semver"},{"version":"6.18","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/sched/core.c","kernel/sched/deadline.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/d7fd56ed5e07e053a5eea6112d61fcaded653b87"},{"url":"https://git.kernel.org/stable/c/ab6c0f158508bb16d483add70b73a73f95651c33"},{"url":"https://git.kernel.org/stable/c/ee6e44dfe6e50b4a5df853d933a96bdff5309e6e"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-06-01T16:05:34.972Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.17","versionEndExcluding":"6.17.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.17","versionEndExcluding":"6.18"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}