{
  "threat_severity" : "Moderate",
  "public_date" : "2025-01-11T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: s390/cpum_sf: Handle CPU hotplug remove during sampling",
    "id" : "2337144",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2337144"
  },
  "cvss3" : {
    "cvss3_base_score" : "5.5",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
    "status" : "verified"
  },
  "cwe" : "CWE-416",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\ns390/cpum_sf: Handle CPU hotplug remove during sampling\nCPU hotplug remove handling triggers the following function\ncall sequence:\nCPUHP_AP_PERF_S390_SF_ONLINE  --> s390_pmu_sf_offline_cpu()\n...\nCPUHP_AP_PERF_ONLINE          --> perf_event_exit_cpu()\nThe s390 CPUMF sampling CPU hotplug handler invokes:\ns390_pmu_sf_offline_cpu()\n+-->  cpusf_pmu_setup()\n+--> setup_pmc_cpu()\n+--> deallocate_buffers()\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.\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:\nperf_event_exit_cpu()\n+--> perf_event_exit_cpu_context()\n+--> __perf_event_exit_context()\n+--> __perf_remove_from_context()\n+--> event_sched_out()\n+--> cpumsf_pmu_del()\n+--> cpumsf_pmu_stop()\n+--> hw_perf_event_update()\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.\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.", "A vulnerability was found in the Linux Kernel. This issue affects performance monitoring on the `s390` architecture during specific CPU hotplug scenarios." ],
  "statement" : "This vulnerability is marked as Moderate rather than Important because its impact is limited to a specific scenario involving CPU hotplug operations on the `s390` architecture with active performance events. While the issue can lead to a use-after-free condition, the scope of exploitation is constrained since it requires precise timing to interact with deallocated sampling data buffers (SDBs) during event cleanup. Moreover, the invalid memory access primarily affects performance monitoring functionality and does not directly compromise critical system processes or user data.",
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2026-09-03T00:00:00Z",
    "advisory" : "RHSA-2026:63013",
    "cpe" : "cpe:/a:redhat:enterprise_linux:8::nfv",
    "package" : "kernel-rt-0:4.18.0-553.159.1.rt7.500.el8_10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2026-09-03T00:00:00Z",
    "advisory" : "RHSA-2026:63014",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8",
    "package" : "kernel-0:4.18.0-553.159.1.el8_10"
  } ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Out of support scope",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Out of support scope",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Will not fix",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Will not fix",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2024-57849\nhttps://nvd.nist.gov/vuln/detail/CVE-2024-57849\nhttps://lore.kernel.org/linux-cve-announce/2025011103-CVE-2024-57849-64db@gregkh/T" ],
  "name" : "CVE-2024-57849",
  "mitigation" : {
    "value" : "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.",
    "lang" : "en:us"
  },
  "csaw" : false
}