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Fencer Vulns
high 7.8

CVE-2025-38234 json

sched/rt: Fix race in push_rt_task

published 2025-07-04 16 mo ago modified 2026-10-30 10 d ago also EUVD-2025-20022

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 6%
public exploits
0
none known

Summary

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

sched/rt: Fix race in push_rt_task

Overview ======== When a CPU chooses to call push_rt_task and picks a task to push to another CPU's runqueue then it will call find_lock_lowest_rq method which would take a double lock on both CPUs' runqueues. If one of the locks aren't readily available, it may lead to dropping the current runqueue lock and reacquiring both the locks at once. During this window it is possible that the task is already migrated and is running on some other CPU. These cases are already handled. However, if the task is migrated and has already been executed and another CPU is now trying to wake it up (ttwu) such that it is queued again on the runqeue (on_rq is 1) and also if the task was run by the same CPU, then the current checks will pass even though the task was migrated out and is no longer in the pushable tasks list.

Crashes ======= This bug resulted in quite a few flavors of crashes triggering kernel panics with various crash signatures such as assert failures, page faults, null pointer dereferences, and queue corruption errors all coming from scheduler itself.

Some of the crashes: -> kernel BUG at kernel/sched/rt.c:1616! BUG_ON(idx >= MAX_RT_PRIO) Call Trace: ? __die_body+0x1a/0x60 ? die+0x2a/0x50 ? do_trap+0x85/0x100 ? pick_next_task_rt+0x6e/0x1d0 ? do_error_trap+0x64/0xa0 ? pick_next_task_rt+0x6e/0x1d0 ? exc_invalid_op+0x4c/0x60 ? pick_next_task_rt+0x6e/0x1d0 ? asm_exc_invalid_op+0x12/0x20 ? pick_next_task_rt+0x6e/0x1d0 __schedule+0x5cb/0x790 ? update_ts_time_stats+0x55/0x70 schedule_idle+0x1e/0x40 do_idle+0x15e/0x200 cpu_startup_entry+0x19/0x20 start_secondary+0x117/0x160 secondary_startup_64_no_verify+0xb0/0xbb

-> BUG: kernel NULL pointer dereference, address: 00000000000000c0 Call Trace: ? __die_body+0x1a/0x60 ? no_context+0x183/0x350 ? __warn+0x8a/0xe0 ? exc_page_fault+0x3d6/0x520 ? asm_exc_page_fault+0x1e/0x30 ? pick_next_task_rt+0xb5/0x1d0 ? pick_next_task_rt+0x8c/0x1d0 __schedule+0x583/0x7e0 ? update_ts_time_stats+0x55/0x70 schedule_idle+0x1e/0x40 do_idle+0x15e/0x200 cpu_startup_entry+0x19/0x20 start_secondary+0x117/0x160 secondary_startup_64_no_verify+0xb0/0xbb

-> BUG: unable to handle page fault for address: ffff9464daea5900 kernel BUG at kernel/sched/rt.c:1861! BUG_ON(rq->cpu != task_cpu(p))

-> kernel BUG at kernel/sched/rt.c:1055! BUG_ON(!rq->nr_running) Call Trace: ? __die_body+0x1a/0x60 ? die+0x2a/0x50 ? do_trap+0x85/0x100 ? dequeue_top_rt_rq+0xa2/0xb0 ? do_error_trap+0x64/0xa0 ? dequeue_top_rt_rq+0xa2/0xb0 ? exc_invalid_op+0x4c/0x60 ? dequeue_top_rt_rq+0xa2/0xb0 ? asm_exc_invalid_op+0x12/0x20 ? dequeue_top_rt_rq+0xa2/0xb0 dequeue_rt_entity+0x1f/0x70 dequeue_task_rt+0x2d/0x70 __schedule+0x1a8/0x7e0 ? blk_finish_plug+0x25/0x40 schedule+0x3c/0xb0 futex_wait_queue_me+0xb6/0x120 futex_wait+0xd9/0x240 do_futex+0x344/0xa90 ? get_mm_exe_file+0x30/0x60 ? audit_exe_compare+0x58/0x70 ? audit_filter_rules.constprop.26+0x65e/0x1220 __x64_sys_futex+0x148/0x1f0 do_syscall_64+0x30/0x80 entry_SYSCALL_64_after_hwframe+0x62/0xc7

-> BUG: unable to handle page fault for address: ffff8cf3608bc2c0 Call Trace: ? __die_body+0x1a/0x60 ? no_context+0x183/0x350 ? spurious_kernel_fault+0x171/0x1c0 ? exc_page_fault+0x3b6/0x520 ? plist_check_list+0x15/0x40 ? plist_check_list+0x2e/0x40 ? asm_exc_page_fault+0x1e/0x30 ? _cond_resched+0x15/0x30 ? futex_wait_queue_me+0xc8/0x120 ? futex_wait+0xd9/0x240 ? try_to_wake_up+0x1b8/0x490 ? futex_wake+0x78/0x160 ? do_futex+0xcd/0xa90 ? plist_check_list+0x15/0x40 ? plist_check_list+0x2e/0x40 ? plist_del+0x6a/0xd0 ? plist_check_list+0x15/0x40 ? plist_check_list+0x2e/0x40 ? dequeue_pushable_task+0x20/0x70 ? __schedule+0x382/0x7e0 ? asm_sysvec_reschedule_i ---truncated---

Patch / fix

  • Linux Linux 6.1.191, 6.6.124, 6.12.64, 6.15.4, 6.16
  • linux Debian 13 6.12.69-1
  • linux Debian 14 6.16.3-1

debian advisories DEBIAN-CVE-2025-38234

  • linux Ubuntu 24.04 LTS 6.8.0-110.110
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1052.55
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1054.57
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1050.56
  • linux-ibm Ubuntu 24.04 LTS 6.8.0-1051.51
  • linux-azure Ubuntu 24.04 LTS 6.8.0-1054.60
  • linux-gkeop Ubuntu 24.04 LTS 6.8.0-1037.40
  • linux-raspi Ubuntu 24.04 LTS 6.8.0-1052.56

ubuntu advisories UBUNTU-CVE-2025-38234

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 9 5.14.0-611.5.1.el9_7
  • rv RHEL 9 5.14.0-611.5.1.el9_7
  • perf RHEL 9 5.14.0-611.5.1.el9_7
  • rtla RHEL 9 5.14.0-611.5.1.el9_7
  • libperf RHEL 9 5.14.0-611.5.1.el9_7
  • kernel-rt RHEL 9 5.14.0-611.5.1.el9_7
  • kernel-64k RHEL 9 5.14.0-611.5.1.el9_7
  • kernel-core RHEL 9 5.14.0-611.5.1.el9_7

red hat advisories RHSA-2025:20518RHSA-2025:20095RHSA-2025:9584RHSA-2025:9348RHSA-2025:8246RHSA-2025:8247

  • kernel-64kb SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS, SLE High Performance Computing 15 SP5-ESPOS 5.14.21-150500.55.144.1
  • kernel-syms SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 5.14.21-150500.55.144.1
  • kernel-source SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +2 more 5.14.21-150500.55.144.1
  • kernel-default SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +3 more 5.14.21-150500.55.144.1
  • kernel-obs-build SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 5.14.21-150500.55.144.1
  • kernel-default-base SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +2 more 5.14.21-150500.55.144.1.150500.6.71.1
  • kernel-rt SLE Micro 5.2 5.3.18-150300.241.1
  • kernel-source-rt SLE Micro 5.2 5.3.18-150300.241.1

suse advisories SUSE-SU-2026:1606-1SUSE-SU-2026:1575-1SUSE-SU-2026:1574-1SUSE-SU-2026:1563-1SUSE-SU-2026:1557-1SUSE-SU-2026:1342-1

  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.6.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.6.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.6.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.6.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.6.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.6.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.6.1
  • kernel-kvmsmall openSUSE Leap 16.0 6.12.0-160000.6.1

opensuse advisories openSUSE-SU-2025:20081-1

  • kernel AlmaLinux 8 4.18.0-553.54.1.el8_10
  • perf AlmaLinux 8 4.18.0-553.54.1.el8_10
  • bpftool AlmaLinux 8 4.18.0-553.54.1.el8_10
  • kernel-core AlmaLinux 8 4.18.0-553.54.1.el8_10
  • kernel-tools AlmaLinux 8 4.18.0-553.54.1.el8_10
  • python3-perf AlmaLinux 8 4.18.0-553.54.1.el8_10
  • kernel-modules AlmaLinux 8 4.18.0-553.54.1.el8_10
  • kernel-zfcpdump AlmaLinux 8 4.18.0-553.54.1.el8_10

almalinux advisories ALSA-2025:8246ALSA-2025:8247

  • kernel Azure Linux 3.0 6.6.126.1-1

azure linux advisories AZL-64728

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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-2025-38234 updated cvss 5.5

kernel: sched/rt: Fix race in push_rt_task

  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more
    affected: no fix available “Fix deferred”
  • Red Hat CodeReady Linux Builder EUS (v.9.4) libperf 5.14.0-427.74.1.el9_4, kernel-debuginfo-common-s390x 5.14.0-427.74.1.el9_4, kernel-debuginfo-common-x86_64 5.14.0-427.74.1.el9_4, kernel-debuginfo-common-aarch64 5.14.0-427.74.1.el9_4, kernel-debuginfo-common-ppc64le 5.14.0-427.74.1.el9_4
    fixed: vendor fix RHSA-2025:9584
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-611.5.1.el9_7, perf 5.14.0-611.5.1.el9_7, rtla 5.14.0-611.5.1.el9_7, python3-perf 5.14.0-611.5.1.el9_7, kernel-devel-matched 5.14.0-611.5.1.el9_7, kernel-64k-devel-matched 5.14.0-611.5.1.el9_7, +7 more
    fixed: vendor fix RHSA-2025:20518
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-124.8.1.el10_1, rv 6.12.0-55.18.1.el10_0, perf 6.12.0-124.8.1.el10_1, perf 6.12.0-55.18.1.el10_0, rtla 6.12.0-124.8.1.el10_1, rtla 6.12.0-55.18.1.el10_0, +20 more
    fixed: vendor fix RHSA-2025:9348
  • Red Hat Enterprise Linux AppStream EUS (v.9.4) rv 5.14.0-427.74.1.el9_4, perf 5.14.0-427.74.1.el9_4, rtla 5.14.0-427.74.1.el9_4, kernel-devel-matched 5.14.0-427.74.1.el9_4, kernel-64k-devel-matched 5.14.0-427.74.1.el9_4, kernel-debug-devel-matched 5.14.0-427.74.1.el9_4, +6 more
    fixed: vendor fix RHSA-2025:9584
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.54.1.el8_10, kernel 4.18.0-553.54.1.el8_10, bpftool 4.18.0-553.54.1.el8_10, kernel-core 4.18.0-553.54.1.el8_10, kernel-tools 4.18.0-553.54.1.el8_10, python3-perf 4.18.0-553.54.1.el8_10, +15 more
    fixed: vendor fix RHSA-2025:8246
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-611.5.1.el9_7, kernel-64k 5.14.0-611.5.1.el9_7, kernel-core 5.14.0-611.5.1.el9_7, kernel-tools 5.14.0-611.5.1.el9_7, kernel-modules 5.14.0-611.5.1.el9_7, kernel-64k-core 5.14.0-611.5.1.el9_7, +27 more
    fixed: vendor fix RHSA-2025:20518
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-124.8.1.el10_1, kernel 6.12.0-55.18.1.el10_0, kernel-64k 6.12.0-124.8.1.el10_1, kernel-64k 6.12.0-55.18.1.el10_0, kernel-core 6.12.0-124.8.1.el10_1, kernel-core 6.12.0-55.18.1.el10_0, +61 more
    fixed: vendor fix RHSA-2025:9348
show 13 more
  • Red Hat Enterprise Linux BaseOS EUS (v.9.4) bpftool 7.3.0-427.74.1.el9_4, kernel 5.14.0-427.74.1.el9_4, kernel-64k 5.14.0-427.74.1.el9_4, kernel-core 5.14.0-427.74.1.el9_4, kernel-tools 5.14.0-427.74.1.el9_4, python3-perf 5.14.0-427.74.1.el9_4, +28 more
    fixed: vendor fix RHSA-2025:9584
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-611.5.1.el9_7, kernel-debuginfo-common-s390x 5.14.0-611.5.1.el9_7, kernel-debuginfo-common-x86_64 5.14.0-611.5.1.el9_7, kernel-debuginfo-common-aarch64 5.14.0-611.5.1.el9_7, kernel-debuginfo-common-ppc64le 5.14.0-611.5.1.el9_7
    fixed: vendor fix RHSA-2025:20518
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-124.8.1.el10_1, libperf 6.12.0-55.18.1.el10_0, kernel-debuginfo-common-s390x 6.12.0-124.8.1.el10_1, kernel-debuginfo-common-s390x 6.12.0-55.18.1.el10_0, kernel-debuginfo-common-x86_64 6.12.0-124.8.1.el10_1, kernel-debuginfo-common-x86_64 6.12.0-55.18.1.el10_0, +4 more
    fixed: vendor fix RHSA-2025:9348
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.54.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.54.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.54.1.el8_10
    fixed: vendor fix RHSA-2025:8246
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.54.1.rt7.395.el8_10, kernel-rt-kvm 4.18.0-553.54.1.rt7.395.el8_10, kernel-rt-core 4.18.0-553.54.1.rt7.395.el8_10, kernel-rt-modules 4.18.0-553.54.1.rt7.395.el8_10, kernel-rt-debug-kvm 4.18.0-553.54.1.rt7.395.el8_10, kernel-rt-debug-core 4.18.0-553.54.1.rt7.395.el8_10, +4 more
    fixed: vendor fix RHSA-2025:8247
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-611.5.1.el9_7, kernel-rt-64k 5.14.0-611.5.1.el9_7, kernel-rt-core 5.14.0-611.5.1.el9_7, kernel-rt-modules 5.14.0-611.5.1.el9_7, kernel-rt-64k-core 5.14.0-611.5.1.el9_7, kernel-rt-debug-core 5.14.0-611.5.1.el9_7, +14 more
    fixed: vendor fix RHSA-2025:20518
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-124.8.1.el10_1, kernel-rt 6.12.0-55.18.1.el10_0, kernel-rt-64k 6.12.0-124.8.1.el10_1, kernel-rt-64k 6.12.0-55.18.1.el10_0, kernel-rt-core 6.12.0-124.8.1.el10_1, kernel-rt-core 6.12.0-55.18.1.el10_0, +34 more
    fixed: vendor fix RHSA-2025:9348
  • Red Hat Enterprise Linux Real Time EUS (v.9.4) kernel-rt 5.14.0-427.74.1.el9_4, kernel-rt-core 5.14.0-427.74.1.el9_4, kernel-rt-modules 5.14.0-427.74.1.el9_4, kernel-rt-debug-core 5.14.0-427.74.1.el9_4, kernel-rt-modules-core 5.14.0-427.74.1.el9_4, kernel-rt-debug-modules 5.14.0-427.74.1.el9_4, +4 more
    fixed: vendor fix RHSA-2025:9584
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-611.5.1.el9_7, kernel-rt-core 5.14.0-611.5.1.el9_7, kernel-rt-modules 5.14.0-611.5.1.el9_7, kernel-rt-debug-core 5.14.0-611.5.1.el9_7, kernel-rt-modules-core 5.14.0-611.5.1.el9_7, kernel-rt-debug-modules 5.14.0-611.5.1.el9_7, +4 more
    fixed: vendor fix RHSA-2025:20518
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-124.8.1.el10_1, kernel-rt 6.12.0-55.18.1.el10_0, kernel-rt-kvm 6.12.0-55.18.1.el10_0, kernel-rt-core 6.12.0-124.8.1.el10_1, kernel-rt-core 6.12.0-55.18.1.el10_0, kernel-rt-modules 6.12.0-124.8.1.el10_1, +16 more
    fixed: vendor fix RHSA-2025:9348
  • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.4) kernel-rt 5.14.0-427.74.1.el9_4, kernel-rt-kvm 5.14.0-427.74.1.el9_4, kernel-rt-core 5.14.0-427.74.1.el9_4, kernel-rt-modules 5.14.0-427.74.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.74.1.el9_4, kernel-rt-debug-core 5.14.0-427.74.1.el9_4, +6 more
    fixed: vendor fix RHSA-2025:9584
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.54.1.rt7.395.el8_10, kernel-rt-core 4.18.0-553.54.1.rt7.395.el8_10, kernel-rt-modules 4.18.0-553.54.1.rt7.395.el8_10, kernel-rt-debug-core 4.18.0-553.54.1.rt7.395.el8_10, kernel-rt-debug-modules 4.18.0-553.54.1.rt7.395.el8_10, kernel-rt-modules-extra 4.18.0-553.54.1.rt7.395.el8_10, +2 more
    fixed: vendor fix RHSA-2025:8247
  • 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

0.17% chance of exploitation in the next 30 days, higher than 6% 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 4.7 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
  • CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization
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.