{"cve":"CVE-2024-57849","nvd":{"published":"2025-01-11T15:15:07.290","modified":"2026-10-15T22:18:03.393","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ns390/cpum_sf: Handle CPU hotplug remove during sampling\n\nCPU hotplug remove handling triggers the following function\ncall sequence:\n\n   CPUHP_AP_PERF_S390_SF_ONLINE  --> s390_pmu_sf_offline_cpu()\n   ...\n   CPUHP_AP_PERF_ONLINE          --> perf_event_exit_cpu()\n\nThe s390 CPUMF sampling CPU hotplug handler invokes:\n\n s390_pmu_sf_offline_cpu()\n +-->  cpusf_pmu_setup()\n       +--> setup_pmc_cpu()\n            +--> deallocate_buffers()\n\nThis function de-allocates all sampling data buffers (SDBs) allocated\nfor that CPU at event initialization. It also clears the\nPMU_F_RESERVED bit. The CPU is gone and can not be sampled.\n\nWith the event still being active on the removed CPU, the CPU event\nhotplug support in kernel performance subsystem triggers the\nfollowing function calls on the removed CPU:\n\n  perf_event_exit_cpu()\n  +--> perf_event_exit_cpu_context()\n       +--> __perf_event_exit_context()\n\t    +--> __perf_remove_from_context()\n\t         +--> event_sched_out()\n\t              +--> cpumsf_pmu_del()\n\t                   +--> cpumsf_pmu_stop()\n                                +--> hw_perf_event_update()\n\nto stop and remove the event. During removal of the event, the\nsampling device driver tries to read out the remaining samples from\nthe sample data buffers (SDBs). But they have already been freed\n(and may have been re-assigned). This may lead to a use after free\nsituation in which case the samples are most likely invalid. In the\nbest case the memory has not been reassigned and still contains\nvalid data.\n\nRemedy this situation and check if the CPU is still in reserved\nstate (bit PMU_F_RESERVED set). In this case the SDBs have not been\nreleased an contain valid data. This is always the case when\nthe event is removed (and no CPU hotplug off occured).\nIf the PMU_F_RESERVED bit is not set, the SDB buffers are gone.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-416"],"references":["https://git.kernel.org/stable/c/06a92f810df8037ca36157282ddcbefdcaf049b8","https://git.kernel.org/stable/c/238e3af849dfdcb1faed544349f7025e533f9aab","https://git.kernel.org/stable/c/99192c735ed4bfdff0d215ec85c8a87a677cb898","https://git.kernel.org/stable/c/a0bd7dacbd51c632b8e2c0500b479af564afadf3","https://git.kernel.org/stable/c/a69752f1e5de817941a2ea0609254f6f25acd274"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:58:20.756570362+00:00"},"epss":{"cve":"CVE-2024-57849","score":0.00209,"percentile":0.10885,"date":"2026-10-26"},"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."]}