Skip to content
Fencer Vulns
high 7.8

CVE-2024-42271 json

net/iucv: fix use after free in iucv_sock_close()

published 2024-08-17 2 y ago modified 2026-08-05 3 mo ago also EUVD-2024-39494

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 14%
public exploits
0
none known

Summary

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

net/iucv: fix use after free in iucv_sock_close()

iucv_sever_path() is called from process context and from bh context. iucv->path is used as indicator whether somebody else is taking care of severing the path (or it is already removed / never existed). This needs to be done with atomic compare and swap, otherwise there is a small window where iucv_sock_close() will try to work with a path that has already been severed and freed by iucv_callback_connrej() called by iucv_tasklet_fn().

Example: [452744.123844] Call Trace: [452744.123845] ([<0000001e87f03880>] 0x1e87f03880) [452744.123966] [<00000000d593001e>] iucv_path_sever+0x96/0x138 [452744.124330] [<000003ff801ddbca>] iucv_sever_path+0xc2/0xd0 [af_iucv] [452744.124336] [<000003ff801e01b6>] iucv_sock_close+0xa6/0x310 [af_iucv] [452744.124341] [<000003ff801e08cc>] iucv_sock_release+0x3c/0xd0 [af_iucv] [452744.124345] [<00000000d574794e>] __sock_release+0x5e/0xe8 [452744.124815] [<00000000d5747a0c>] sock_close+0x34/0x48 [452744.124820] [<00000000d5421642>] __fput+0xba/0x268 [452744.124826] [<00000000d51b382c>] task_work_run+0xbc/0xf0 [452744.124832] [<00000000d5145710>] do_notify_resume+0x88/0x90 [452744.124841] [<00000000d5978096>] system_call+0xe2/0x2c8 [452744.125319] Last Breaking-Event-Address: [452744.125321] [<00000000d5930018>] iucv_path_sever+0x90/0x138 [452744.125324] [452744.125325] Kernel panic - not syncing: Fatal exception in interrupt

Note that bh_lock_sock() is not serializing the tasklet context against process context, because the check for sock_owned_by_user() and corresponding handling is missing.

Ideas for a future clean-up patch: A) Correct usage of bh_lock_sock() in tasklet context, as described in Re-enqueue, if needed. This may require adding return values to the tasklet functions and thus changes to all users of iucv.

B) Change iucv tasklet into worker and use only lock_sock() in af_iucv.

Patch / fix

  • Linux Linux 4.19.320, 5.4.282, 5.10.224, 5.15.165, 6.1.104, 6.6.45, 6.10.4, 6.11
  • linux Debian 12 6.1.106-1
  • linux Debian 14, Debian 13 6.10.4-1

debian advisories DEBIAN-CVE-2024-42271

  • linux Ubuntu 20.04 LTS 5.4.0-200.220
  • linux Ubuntu 22.04 LTS 5.15.0-125.135
  • linux Ubuntu 24.04 LTS 6.8.0-48.48
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1135.145
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1072.78
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1018.20
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1139.148
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1071.79

ubuntu advisories UBUNTU-CVE-2024-42271

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 5.14.0-503.11.1.el9_5
  • rv RHEL 9 5.14.0-503.11.1.el9_5
  • perf RHEL 9 5.14.0-503.11.1.el9_5
  • rtla RHEL 9 5.14.0-503.11.1.el9_5
  • bpftool RHEL 9 7.4.0-503.11.1.el9_5
  • libperf RHEL 9 5.14.0-503.11.1.el9_5
  • kernel-rt RHEL 9 5.14.0-503.11.1.el9_5
  • kernel-64k RHEL 9 5.14.0-503.11.1.el9_5

red hat advisories RHSA-2024:10771RHSA-2024:9315RHSA-2024:9498RHSA-2024:9497

  • kernel-rt Linux Micro 6.0 6.4.0-10.1
  • kernel-source-rt Linux Micro 6.0 6.4.0-10.1
  • kernel-livepatch-MICRO-6-0-RT_Update_2 Linux Micro 6.0 1-1.1
  • kernel-source Linux Micro 6.0 6.4.0-19.1
  • kernel-default Linux Micro 6.0 6.4.0-19.1
  • kernel-kvmsmall Linux Micro 6.0 6.4.0-19.1
  • kernel-default-base Linux Micro 6.0 6.4.0-17.1.1.51
  • kernel-livepatch-MICRO-6-0_Update_2 Linux Micro 6.0 1-1.1

suse advisories SUSE-SU-2025:20047-1SUSE-SU-2025:20044-1SUSE-SU-2024:3499-1SUSE-SU-2024:3483-1SUSE-SU-2024:3408-1SUSE-SU-2024:3383-1

  • kernel Azure Linux 3.0 6.6.47.1-1
  • kernel CBL-Mariner 2.0 5.15.167.1-1

azure linux advisories AZL-47808AZL-47853

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-2024-42271 updated cvss 6.3

kernel: net/iucv: fix use after free in iucv_sock_close()

  • 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
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 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 planned “Will not fix”
  • Red Hat CodeReady Linux Builder (v. 9) libperf 5.14.0-503.11.1.el9_5, kernel-debuginfo-common-s390x 5.14.0-503.11.1.el9_5, kernel-debuginfo-common-x86_64 5.14.0-503.11.1.el9_5, kernel-debuginfo-common-aarch64 5.14.0-503.11.1.el9_5, kernel-debuginfo-common-ppc64le 5.14.0-503.11.1.el9_5
    fixed: vendor fix RHSA-2024:9315
  • Red Hat CodeReady Linux Builder EUS (v.9.2) kernel-debuginfo-common-s390x 5.14.0-284.92.1.el9_2, kernel-debuginfo-common-x86_64 5.14.0-284.92.1.el9_2, kernel-debuginfo-common-aarch64 5.14.0-284.92.1.el9_2, kernel-debuginfo-common-ppc64le 5.14.0-284.92.1.el9_2
    fixed: vendor fix RHSA-2024:9497
  • Red Hat CodeReady Linux Builder EUS (v.9.4) libperf 5.14.0-427.47.1.el9_4, kernel-debuginfo-common-s390x 5.14.0-427.47.1.el9_4, kernel-debuginfo-common-x86_64 5.14.0-427.47.1.el9_4, kernel-debuginfo-common-aarch64 5.14.0-427.47.1.el9_4, kernel-debuginfo-common-ppc64le 5.14.0-427.47.1.el9_4
    fixed: vendor fix RHSA-2024:10771
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-503.11.1.el9_5, perf 5.14.0-503.11.1.el9_5, rtla 5.14.0-503.11.1.el9_5, kernel-devel-matched 5.14.0-503.11.1.el9_5, kernel-64k-devel-matched 5.14.0-503.11.1.el9_5, kernel-debug-devel-matched 5.14.0-503.11.1.el9_5, +6 more
    fixed: vendor fix RHSA-2024:9315
  • Red Hat Enterprise Linux AppStream EUS (v.9.2) perf 5.14.0-284.92.1.el9_2, rtla 5.14.0-284.92.1.el9_2, kernel-devel-matched 5.14.0-284.92.1.el9_2, kernel-64k-devel-matched 5.14.0-284.92.1.el9_2, kernel-debug-devel-matched 5.14.0-284.92.1.el9_2, kernel-debuginfo-common-s390x 5.14.0-284.92.1.el9_2, +5 more
    fixed: vendor fix RHSA-2024:9497
  • Red Hat Enterprise Linux AppStream EUS (v.9.4) rv 5.14.0-427.47.1.el9_4, perf 5.14.0-427.47.1.el9_4, rtla 5.14.0-427.47.1.el9_4, kernel-devel-matched 5.14.0-427.47.1.el9_4, kernel-64k-devel-matched 5.14.0-427.47.1.el9_4, kernel-debug-devel-matched 5.14.0-427.47.1.el9_4, +6 more
    fixed: vendor fix RHSA-2024:10771
show 10 more
  • Red Hat Enterprise Linux BaseOS (v. 9) bpftool 7.4.0-503.11.1.el9_5, kernel 5.14.0-503.11.1.el9_5, kernel-64k 5.14.0-503.11.1.el9_5, kernel-core 5.14.0-503.11.1.el9_5, kernel-tools 5.14.0-503.11.1.el9_5, python3-perf 5.14.0-503.11.1.el9_5, +29 more
    fixed: vendor fix RHSA-2024:9315
  • Red Hat Enterprise Linux BaseOS EUS (v.9.2) bpftool 7.0.0-284.92.1.el9_2, kernel 5.14.0-284.92.1.el9_2, kernel-64k 5.14.0-284.92.1.el9_2, kernel-core 5.14.0-284.92.1.el9_2, kernel-tools 5.14.0-284.92.1.el9_2, python3-perf 5.14.0-284.92.1.el9_2, +28 more
    fixed: vendor fix RHSA-2024:9497
  • Red Hat Enterprise Linux BaseOS EUS (v.9.4) bpftool 7.3.0-427.47.1.el9_4, kernel 5.14.0-427.47.1.el9_4, kernel-64k 5.14.0-427.47.1.el9_4, kernel-core 5.14.0-427.47.1.el9_4, kernel-tools 5.14.0-427.47.1.el9_4, python3-perf 5.14.0-427.47.1.el9_4, +28 more
    fixed: vendor fix RHSA-2024:10771
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-503.11.1.el9_5, kernel-rt-core 5.14.0-503.11.1.el9_5, kernel-rt-modules 5.14.0-503.11.1.el9_5, kernel-rt-debug-core 5.14.0-503.11.1.el9_5, kernel-rt-modules-core 5.14.0-503.11.1.el9_5, kernel-rt-debug-modules 5.14.0-503.11.1.el9_5, +4 more
    fixed: vendor fix RHSA-2024:9315
  • Red Hat Enterprise Linux Real Time EUS (v.9.2) kernel-rt 5.14.0-284.92.1.rt14.377.el9_2, kernel-rt-core 5.14.0-284.92.1.rt14.377.el9_2, kernel-rt-modules 5.14.0-284.92.1.rt14.377.el9_2, kernel-rt-debug-core 5.14.0-284.92.1.rt14.377.el9_2, kernel-rt-modules-core 5.14.0-284.92.1.rt14.377.el9_2, kernel-rt-debug-modules 5.14.0-284.92.1.rt14.377.el9_2, +4 more
    fixed: vendor fix RHSA-2024:9498
  • Red Hat Enterprise Linux Real Time EUS (v.9.4) kernel-rt 5.14.0-427.47.1.el9_4, kernel-rt-core 5.14.0-427.47.1.el9_4, kernel-rt-modules 5.14.0-427.47.1.el9_4, kernel-rt-debug-core 5.14.0-427.47.1.el9_4, kernel-rt-modules-core 5.14.0-427.47.1.el9_4, kernel-rt-debug-modules 5.14.0-427.47.1.el9_4, +4 more
    fixed: vendor fix RHSA-2024:10771
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-503.11.1.el9_5, kernel-rt-kvm 5.14.0-503.11.1.el9_5, kernel-rt-core 5.14.0-503.11.1.el9_5, kernel-rt-modules 5.14.0-503.11.1.el9_5, kernel-rt-debug-kvm 5.14.0-503.11.1.el9_5, kernel-rt-debug-core 5.14.0-503.11.1.el9_5, +6 more
    fixed: vendor fix RHSA-2024:9315
  • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.2) kernel-rt 5.14.0-284.92.1.rt14.377.el9_2, kernel-rt-kvm 5.14.0-284.92.1.rt14.377.el9_2, kernel-rt-core 5.14.0-284.92.1.rt14.377.el9_2, kernel-rt-modules 5.14.0-284.92.1.rt14.377.el9_2, kernel-rt-debug-kvm 5.14.0-284.92.1.rt14.377.el9_2, kernel-rt-debug-core 5.14.0-284.92.1.rt14.377.el9_2, +6 more
    fixed: vendor fix RHSA-2024:9498
  • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.4) kernel-rt 5.14.0-427.47.1.el9_4, kernel-rt-kvm 5.14.0-427.47.1.el9_4, kernel-rt-core 5.14.0-427.47.1.el9_4, kernel-rt-modules 5.14.0-427.47.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.47.1.el9_4, kernel-rt-debug-core 5.14.0-427.47.1.el9_4, +6 more
    fixed: vendor fix RHSA-2024:10771
  • Red Hat CodeReady Linux Builder (v. 9) kernel-cross-headers 5.14.0-503.11.1.el9_5 Red Hat Enterprise Linux AppStream (v. 9) kernel-headers 5.14.0-503.11.1.el9_5 Red Hat Enterprise Linux AppStream EUS (v.9.2) kernel-doc 5.14.0-284.92.1.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

0.24% chance of exploitation in the next 30 days, higher than 14% 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.