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Fencer Vulns
high 7.8

CVE-2024-57849 json

s390/cpum_sf: Handle CPU hotplug remove during sampling

published 2025-01-11 21 mo ago modified 2026-10-15 24 d ago also EUVD-2024-53773

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 11%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

s390/cpum_sf: Handle CPU hotplug remove during sampling

CPU hotplug remove handling triggers the following function call sequence:

CPUHP_AP_PERF_S390_SF_ONLINE --> s390_pmu_sf_offline_cpu() ... CPUHP_AP_PERF_ONLINE --> perf_event_exit_cpu()

The s390 CPUMF sampling CPU hotplug handler invokes:

s390_pmu_sf_offline_cpu() +--> cpusf_pmu_setup() +--> setup_pmc_cpu() +--> deallocate_buffers()

This function de-allocates all sampling data buffers (SDBs) allocated for that CPU at event initialization. It also clears the PMU_F_RESERVED bit. The CPU is gone and can not be sampled.

With the event still being active on the removed CPU, the CPU event hotplug support in kernel performance subsystem triggers the following function calls on the removed CPU:

perf_event_exit_cpu() +--> perf_event_exit_cpu_context() +--> __perf_event_exit_context() +--> __perf_remove_from_context() +--> event_sched_out() +--> cpumsf_pmu_del() +--> cpumsf_pmu_stop() +--> hw_perf_event_update()

to stop and remove the event. During removal of the event, the sampling device driver tries to read out the remaining samples from the sample data buffers (SDBs). But they have already been freed (and may have been re-assigned). This may lead to a use after free situation in which case the samples are most likely invalid. In the best case the memory has not been reassigned and still contains valid data.

Remedy this situation and check if the CPU is still in reserved state (bit PMU_F_RESERVED set). In this case the SDBs have not been released an contain valid data. This is always the case when the event is removed (and no CPU hotplug off occured). If the PMU_F_RESERVED bit is not set, the SDB buffers are gone.

Patch / fix

  • Linux Linux 5.4.287, 5.10.231, 5.15.174, 6.1.120, 6.6.66, 6.12.5, 6.13
  • linux Debian 12 6.1.123-1
  • linux Debian 14, Debian 13 6.12.5-1

debian advisories DEBIAN-CVE-2024-57849

  • linux Ubuntu 20.04 LTS 5.4.0-211.231
  • linux Ubuntu 22.04 LTS 5.15.0-135.146
  • linux Ubuntu 24.04 LTS 6.8.0-58.60
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1142.152
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1080.87
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1027.29
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1145.154
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1079.88

ubuntu advisories UBUNTU-CVE-2024-57849

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel RHEL 8 4.18.0-553.159.1.el8_10
  • perf RHEL 8 4.18.0-553.159.1.el8_10
  • bpftool RHEL 8 4.18.0-553.159.1.el8_10
  • kernel-core RHEL 8 4.18.0-553.159.1.el8_10
  • kernel-tools RHEL 8 4.18.0-553.159.1.el8_10
  • python3-perf RHEL 8 4.18.0-553.159.1.el8_10
  • kernel-modules RHEL 8 4.18.0-553.159.1.el8_10
  • kernel-zfcpdump RHEL 8 4.18.0-553.159.1.el8_10

red hat advisories RHSA-2026:63014RHSA-2026:63013

  • kernel-livepatch-MICRO-6-0_Update_4 Linux Micro 6.1, Linux Micro 6.0 15-1.2
  • kernel-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-25.1
  • kernel-source-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-25.1
  • kernel-livepatch-MICRO-6-0-RT_Update_5 Linux Micro 6.1, Linux Micro 6.0 1-1.1
  • kernel-source Linux Micro 6.1, Linux Micro 6.0 6.4.0-25.1
  • kernel-default Linux Micro 6.1, Linux Micro 6.0 6.4.0-25.1
  • kernel-kvmsmall Linux Micro 6.1, Linux Micro 6.0 6.4.0-25.1
  • kernel-default-base Linux Micro 6.1, Linux Micro 6.0 6.4.0-24.1.21.4

suse advisories SUSE-SU-2026:0269-1SUSE-SU-2026:0246-1SUSE-SU-2026:0174-1SUSE-SU-2026:0173-1SUSE-SU-2026:20255-1SUSE-SU-2026:20376-1

  • kernel-rt AlmaLinux 8 4.18.0-553.159.1.rt7.500.el8_10
  • kernel-rt-core AlmaLinux 8 4.18.0-553.159.1.rt7.500.el8_10
  • kernel-rt-modules AlmaLinux 8 4.18.0-553.159.1.rt7.500.el8_10
  • kernel-rt-debug-core AlmaLinux 8 4.18.0-553.159.1.rt7.500.el8_10
  • kernel-rt-debug-modules AlmaLinux 8 4.18.0-553.159.1.rt7.500.el8_10
  • kernel-rt-modules-extra AlmaLinux 8 4.18.0-553.159.1.rt7.500.el8_10
  • kernel-rt-debug-modules-extra AlmaLinux 8 4.18.0-553.159.1.rt7.500.el8_10
  • kernel AlmaLinux 8 4.18.0-553.159.1.el8_10

almalinux advisories ALSA-2026:63013ALSA-2026:63014

  • kernel-rt Rocky Linux 8 4.18.0-553.159.1.rt7.500.el8_10
  • kernel Rocky Linux 8 4.18.0-553.159.1.el8_10

rocky linux advisories RLSA-2026:63013RLSA-2026:63014

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2024-57849 updated cvss 6.6

kernel: s390/cpum_sf: Handle CPU hotplug remove during sampling

  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +82 more
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.159.1.el8_10, kernel 4.18.0-553.159.1.el8_10, bpftool 4.18.0-553.159.1.el8_10, kernel-core 4.18.0-553.159.1.el8_10, kernel-tools 4.18.0-553.159.1.el8_10, python3-perf 4.18.0-553.159.1.el8_10, +15 more Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.159.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.159.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.159.1.el8_10
    fixed: vendor fix RHSA-2026:63014
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-kvm 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-core 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-modules 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-debug-kvm 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-debug-core 4.18.0-553.159.1.rt7.500.el8_10, +4 more Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-core 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-modules 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-debug-core 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-debug-modules 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-modules-extra 4.18.0-553.159.1.rt7.500.el8_10, +2 more
    fixed: vendor fix RHSA-2026:63013
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
24 d ago

Exploit prediction

0.21% chance of exploitation in the next 30 days, higher than 11% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.