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Fencer Vulns
high 7.8

CVE-2023-52707 json

sched/psi: Fix use-after-free in ep_remove_wait_queue()

published 2024-05-21 2 y ago modified 2026-08-05 3 mo ago also EUVD-2023-57331

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 18%
public exploits
0
none known

Summary

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

sched/psi: Fix use-after-free in ep_remove_wait_queue()

If a non-root cgroup gets removed when there is a thread that registered trigger and is polling on a pressure file within the cgroup, the polling waitqueue gets freed in the following path:

do_rmdir cgroup_rmdir kernfs_drain_open_files cgroup_file_release cgroup_pressure_release psi_trigger_destroy

However, the polling thread still has a reference to the pressure file and will access the freed waitqueue when the file is closed or upon exit:

fput ep_eventpoll_release ep_free ep_remove_wait_queue remove_wait_queue

This results in use-after-free as pasted below.

The fundamental problem here is that cgroup_file_release() (and consequently waitqueue's lifetime) is not tied to the file's real lifetime. Using wake_up_pollfree() here might be less than ideal, but it is in line with the comment at commit 42288cb44c4b ("wait: add wake_up_pollfree()") since the waitqueue's lifetime is not tied to file's one and can be considered as another special case. While this would be fixable by somehow making cgroup_file_release() be tied to the fput(), it would require sizable refactoring at cgroups or higher layer which might be more justifiable if we identify more cases like this.

BUG: KASAN: use-after-free in _raw_spin_lock_irqsave+0x60/0xc0 Write of size 4 at addr ffff88810e625328 by task a.out/4404

CPU: 19 PID: 4404 Comm: a.out Not tainted 6.2.0-rc6 #38 Hardware name: Amazon EC2 c5a.8xlarge/, BIOS 1.0 10/16/2017 Call Trace: <TASK> dump_stack_lvl+0x73/0xa0 print_report+0x16c/0x4e0 kasan_report+0xc3/0xf0 kasan_check_range+0x2d2/0x310 _raw_spin_lock_irqsave+0x60/0xc0 remove_wait_queue+0x1a/0xa0 ep_free+0x12c/0x170 ep_eventpoll_release+0x26/0x30 __fput+0x202/0x400 task_work_run+0x11d/0x170 do_exit+0x495/0x1130 do_group_exit+0x100/0x100 get_signal+0xd67/0xde0 arch_do_signal_or_restart+0x2a/0x2b0 exit_to_user_mode_prepare+0x94/0x100 syscall_exit_to_user_mode+0x20/0x40 do_syscall_64+0x52/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd </TASK>

Allocated by task 4404:

kasan_set_track+0x3d/0x60 __kasan_kmalloc+0x85/0x90 psi_trigger_create+0x113/0x3e0 pressure_write+0x146/0x2e0 cgroup_file_write+0x11c/0x250 kernfs_fop_write_iter+0x186/0x220 vfs_write+0x3d8/0x5c0 ksys_write+0x90/0x110 do_syscall_64+0x43/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Freed by task 4407:

kasan_set_track+0x3d/0x60 kasan_save_free_info+0x27/0x40 ____kasan_slab_free+0x11d/0x170 slab_free_freelist_hook+0x87/0x150 __kmem_cache_free+0xcb/0x180 psi_trigger_destroy+0x2e8/0x310 cgroup_file_release+0x4f/0xb0 kernfs_drain_open_files+0x165/0x1f0 kernfs_drain+0x162/0x1a0 __kernfs_remove+0x1fb/0x310 kernfs_remove_by_name_ns+0x95/0xe0 cgroup_addrm_files+0x67f/0x700 cgroup_destroy_locked+0x283/0x3c0 cgroup_rmdir+0x29/0x100 kernfs_iop_rmdir+0xd1/0x140 vfs_rmdir+0xfe/0x240 do_rmdir+0x13d/0x280 __x64_sys_rmdir+0x2c/0x30 do_syscall_64+0x43/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Patch / fix

  • Linux Linux 5.4.232, 5.10.169, 5.15.95, 6.1.13, 6.2
  • linux Debian 14, Debian 13, Debian 12 6.1.15-1

debian advisories DEBIAN-CVE-2023-52707

  • linux Ubuntu 20.04 LTS 5.4.0-149.166
  • linux Ubuntu 22.04 LTS 5.15.0-72.79
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1102.110
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1036.40
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1105.114
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1034.42
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1033.38
  • linux-ibm Ubuntu 20.04 LTS 5.4.0-1049.54

ubuntu advisories UBUNTU-CVE-2023-52707

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-rt RHEL 8 4.18.0-553.16.1.rt7.357.el8_10
  • kernel-rt-kvm RHEL 8 4.18.0-553.16.1.rt7.357.el8_10
  • kernel-rt-core RHEL 8 4.18.0-553.16.1.rt7.357.el8_10
  • kernel-rt-modules RHEL 8 4.18.0-553.16.1.rt7.357.el8_10
  • kernel-rt-debug-kvm RHEL 8 4.18.0-553.16.1.rt7.357.el8_10
  • kernel-rt-debug-core RHEL 8 4.18.0-553.16.1.rt7.357.el8_10
  • kernel-rt-debug-modules RHEL 8 4.18.0-553.16.1.rt7.357.el8_10
  • kernel-rt-modules-extra RHEL 8 4.18.0-553.16.1.rt7.357.el8_10

red hat advisories RHSA-2024:5102RHSA-2024:5101RHSA-2024:4823RHSA-2024:4831RHSA-2023:6583

  • kernel-rt SLE Micro 5.2, SLE Micro 5.1 5.3.18-150300.175.1
  • kernel-source-rt SLE Micro 5.2, SLE Micro 5.1 5.3.18-150300.175.1
  • kernel-default SLES for SAP 15 SP2, SLES 15 SP2-LTSS, SLE Live Patching 15 SP2 +2 more 5.3.18-150200.24.197.1
  • kernel-64kb SLES 15 SP3-LTSS, SLE High Performance Computing 15 SP3-LTSS, Enterprise Storage 7.1 5.3.18-150300.59.167.1
  • kernel-syms SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE High Performance Computing 15 SP3-LTSS +1 more 5.3.18-150300.59.167.1
  • kernel-source SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE High Performance Computing 15 SP3-LTSS +1 more 5.3.18-150300.59.167.1
  • kernel-default SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE Micro 5.2 +5 more 5.3.18-150300.59.167.1
  • kernel-preempt SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE High Performance Computing 15 SP3-LTSS +1 more 5.3.18-150300.59.167.1

suse advisories SUSE-SU-2024:2384-1SUSE-SU-2024:2365-1SUSE-SU-2024:2362-1SUSE-SU-2024:2190-1SUSE-SU-2024:2189-1SUSE-SU-2024:2019-1

  • kernel AlmaLinux 8 4.18.0-553.16.1.el8_10
  • perf AlmaLinux 8 4.18.0-553.16.1.el8_10
  • bpftool AlmaLinux 8 4.18.0-553.16.1.el8_10
  • kernel-core AlmaLinux 8 4.18.0-553.16.1.el8_10
  • kernel-tools AlmaLinux 8 4.18.0-553.16.1.el8_10
  • python3-perf AlmaLinux 8 4.18.0-553.16.1.el8_10
  • kernel-modules AlmaLinux 8 4.18.0-553.16.1.el8_10
  • kernel-zfcpdump AlmaLinux 8 4.18.0-553.16.1.el8_10

almalinux advisories ALSA-2024:5101ALSA-2024:5102

  • kernel Rocky Linux 8 4.18.0-553.16.1.el8_10.cloud.0.1
  • kernel-rt Rocky Linux 8 4.18.0-553.16.1.rt7.357.el8_10
  • kernel Rocky Linux 8 4.18.0-553.16.1.el8_10

rocky linux advisories RXSA-2024:5101RLSA-2024:5102RLSA-2024:5101

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-2023-52707 updated cvss 7.0

kernel: sched/psi: Fix use-after-free in ep_remove_wait_queue()

  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    affected: no fix available
  • Red Hat CodeReady Linux Builder EUS (v.9.2) kernel-debuginfo-common-s390x 5.14.0-284.75.1.el9_2, kernel-debuginfo-common-x86_64 5.14.0-284.75.1.el9_2, kernel-debuginfo-common-aarch64 5.14.0-284.75.1.el9_2, kernel-debuginfo-common-ppc64le 5.14.0-284.75.1.el9_2 Red Hat Enterprise Linux AppStream EUS (v.9.2) perf 5.14.0-284.75.1.el9_2, rtla 5.14.0-284.75.1.el9_2, kernel-devel-matched 5.14.0-284.75.1.el9_2, kernel-64k-devel-matched 5.14.0-284.75.1.el9_2, kernel-debug-devel-matched 5.14.0-284.75.1.el9_2, kernel-debuginfo-common-s390x 5.14.0-284.75.1.el9_2, +5 more
    fixed: vendor fix RHSA-2024:4823
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.16.1.el8_10, kernel 4.18.0-553.16.1.el8_10, bpftool 4.18.0-553.16.1.el8_10, kernel-core 4.18.0-553.16.1.el8_10, kernel-tools 4.18.0-553.16.1.el8_10, python3-perf 4.18.0-553.16.1.el8_10, +15 more
    fixed: vendor fix RHSA-2024:5101
  • Red Hat Enterprise Linux BaseOS EUS (v.9.2) bpftool 7.0.0-284.75.1.el9_2, kernel 5.14.0-284.75.1.el9_2, kernel-64k 5.14.0-284.75.1.el9_2, kernel-core 5.14.0-284.75.1.el9_2, kernel-tools 5.14.0-284.75.1.el9_2, python3-perf 5.14.0-284.75.1.el9_2, +28 more
    fixed: vendor fix RHSA-2024:4823
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.16.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.16.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.16.1.el8_10
    fixed: vendor fix RHSA-2024:5101
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.16.1.rt7.357.el8_10, kernel-rt-kvm 4.18.0-553.16.1.rt7.357.el8_10, kernel-rt-core 4.18.0-553.16.1.rt7.357.el8_10, kernel-rt-modules 4.18.0-553.16.1.rt7.357.el8_10, kernel-rt-debug-kvm 4.18.0-553.16.1.rt7.357.el8_10, kernel-rt-debug-core 4.18.0-553.16.1.rt7.357.el8_10, +4 more
    fixed: vendor fix RHSA-2024:5102
  • Red Hat Enterprise Linux Real Time EUS (v.9.2) kernel-rt 5.14.0-284.75.1.rt14.360.el9_2, kernel-rt-core 5.14.0-284.75.1.rt14.360.el9_2, kernel-rt-modules 5.14.0-284.75.1.rt14.360.el9_2, kernel-rt-debug-core 5.14.0-284.75.1.rt14.360.el9_2, kernel-rt-modules-core 5.14.0-284.75.1.rt14.360.el9_2, kernel-rt-debug-modules 5.14.0-284.75.1.rt14.360.el9_2, +4 more Red Hat Enterprise Linux Real Time for NFV EUS (v.9.2) kernel-rt 5.14.0-284.75.1.rt14.360.el9_2, kernel-rt-kvm 5.14.0-284.75.1.rt14.360.el9_2, kernel-rt-core 5.14.0-284.75.1.rt14.360.el9_2, kernel-rt-modules 5.14.0-284.75.1.rt14.360.el9_2, kernel-rt-debug-kvm 5.14.0-284.75.1.rt14.360.el9_2, kernel-rt-debug-core 5.14.0-284.75.1.rt14.360.el9_2, +6 more
    fixed: vendor fix RHSA-2024:4831
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.16.1.rt7.357.el8_10, kernel-rt-core 4.18.0-553.16.1.rt7.357.el8_10, kernel-rt-modules 4.18.0-553.16.1.rt7.357.el8_10, kernel-rt-debug-core 4.18.0-553.16.1.rt7.357.el8_10, kernel-rt-debug-modules 4.18.0-553.16.1.rt7.357.el8_10, kernel-rt-modules-extra 4.18.0-553.16.1.rt7.357.el8_10, +2 more
    fixed: vendor fix RHSA-2024:5102
show 1 more
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux AppStream EUS (v.9.2) kernel-doc 5.14.0-284.75.1.el9_2
    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
partial
Assessed
2 y ago

Exploit prediction

0.26% chance of exploitation in the next 30 days, higher than 18% 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.