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Fencer Vulns
medium 5.5

CVE-2026-23002 json

lib/buildid: use __kernel_read() for sleepable context

published 2026-01-25 9 mo ago modified 2026-11-05 3 d ago also EUVD-2026-4620

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 7%
public exploits
0
none known

Summary

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

lib/buildid: use __kernel_read() for sleepable context

Prevent a "BUG: unable to handle kernel NULL pointer dereference in filemap_read_folio".

For the sleepable context, convert freader to use __kernel_read() instead of direct page cache access via read_cache_folio(). This simplifies the faultable code path by using the standard kernel file reading interface which handles all the complexity of reading file data.

At the moment we are not changing the code for non-sleepable context which uses filemap_get_folio() and only succeeds if the target folios are already in memory and up-to-date. The reason is to keep the patch simple and easier to backport to stable kernels.

Syzbot repro does not crash the kernel anymore and the selftests run successfully.

In the follow up we will make __kernel_read() with IOCB_NOWAIT work for non-sleepable contexts. In addition, I would like to replace the secretmem check with a more generic approach and will add fstest for the buildid code.

Patch / fix

  • Linux Linux 6.12.67, 6.18.7, 6.19
  • linux Debian 13 6.12.69-1
  • linux Debian 14 6.18.8-1

debian advisories DEBIAN-CVE-2026-23002

  • linux-gcp-6.17 Ubuntu 24.04 LTS 6.17.0-1021.24~24.04.1
  • linux-hwe-6.17 Ubuntu 24.04 LTS 6.17.0-41.41~24.04.1
  • linux-oem-6.17 Ubuntu 24.04 LTS 6.17.0-1030.30
  • linux-azure-6.17 Ubuntu 24.04 LTS 6.17.0-1021.21~24.04.1
  • linux-nvidia-6.17 Ubuntu 24.04 LTS 6.17.0-1031.31
  • linux-oracle-6.17 Ubuntu 24.04 LTS 6.17.0-1019.19~24.04.3
  • linux-realtime-6.17 Ubuntu Pro Realtime 24.04 LTS 6.17.0-1018.20~24.04.1

ubuntu advisories UBUNTU-CVE-2026-23002

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 5.14.0-687.31.1.el9_8
  • rv RHEL 9 5.14.0-687.31.1.el9_8
  • perf RHEL 9 5.14.0-687.31.1.el9_8
  • rtla RHEL 9 5.14.0-687.31.1.el9_8
  • libperf RHEL 9 5.14.0-687.31.1.el9_8
  • kernel-rt RHEL 9 5.14.0-687.31.1.el9_8
  • kernel-64k RHEL 9 5.14.0-687.31.1.el9_8
  • kernel-core RHEL 9 5.14.0-687.31.1.el9_8

red hat advisories RHSA-2026:47040RHSA-2026:18134

  • kernel-rt Linux Micro 6.2 6.12.0-160000.26.1
  • kernel-64kb SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.26.1
  • kernel-source SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.26.1
  • kernel-default SLES 16.0, SLE High Availability Extension 16.0, Linux Micro 6.2 +1 more 6.12.0-160000.26.1
  • kernel-default-base SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.26.1.160000.2.7
  • kernel-syms SLES 16.0, Linux Micro Extras 6.2, SLES for SAP applications 16.0 6.12.0-160000.26.1
  • kernel-azure SLES for SAP applications 16.0, SLES 16.0 6.12.0-160000.26.1
  • kernel-obs-qa SLES for SAP applications 16.0, SLES 16.0 6.12.0-160000.26.1

suse advisories SUSE-SU-2026:20555-1SUSE-SU-2026:20599-1SUSE-SU-2026:20615-1SUSE-SU-2026:20570-1

  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.26.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.26.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.26.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.26.1
  • kernel-azure openSUSE Leap 16.0 6.12.0-160000.26.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.26.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.26.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.26.1

opensuse advisories openSUSE-SU-2026:20287-1

  • kernel AlmaLinux 9 5.14.0-687.31.1.el9_8
  • rv AlmaLinux 9 5.14.0-687.31.1.el9_8
  • perf AlmaLinux 9 5.14.0-687.31.1.el9_8
  • rtla AlmaLinux 9 5.14.0-687.31.1.el9_8
  • libperf AlmaLinux 9 5.14.0-687.31.1.el9_8
  • kernel-rt AlmaLinux 9 5.14.0-687.31.1.el9_8
  • kernel-64k AlmaLinux 9 5.14.0-687.31.1.el9_8
  • kernel-core AlmaLinux 9 5.14.0-687.31.1.el9_8

almalinux advisories ALSA-2026:47040ALSA-2026:18134

  • kernel Rocky Linux 9 5.14.0-687.31.1.el9_8

rocky linux advisories RLSA-2026:47040

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-2026-23002 updated cvss 4.7

kernel: lib/buildid: use __kernel_read() for sleepable context

  • 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 Enterprise Linux AppStream (v. 9) rv 5.14.0-687.31.1.el9_8, perf 5.14.0-687.31.1.el9_8, rtla 5.14.0-687.31.1.el9_8, python3-perf 5.14.0-687.31.1.el9_8, kernel-devel-matched 5.14.0-687.31.1.el9_8, kernel-64k-devel-matched 5.14.0-687.31.1.el9_8, +7 more
    fixed: vendor fix RHSA-2026:47040
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-211.7.1.el10_2, perf 6.12.0-211.7.1.el10_2, rtla 6.12.0-211.7.1.el10_2, python3-perf 6.12.0-211.7.1.el10_2, kernel-devel-matched 6.12.0-211.7.1.el10_2, kernel-64k-devel-matched 6.12.0-211.7.1.el10_2, +7 more
    fixed: vendor fix RHSA-2026:18134
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-687.31.1.el9_8, kernel-64k 5.14.0-687.31.1.el9_8, kernel-core 5.14.0-687.31.1.el9_8, kernel-tools 5.14.0-687.31.1.el9_8, kernel-modules 5.14.0-687.31.1.el9_8, kernel-64k-core 5.14.0-687.31.1.el9_8, +27 more
    fixed: vendor fix RHSA-2026:47040
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-211.7.1.el10_2, kernel-64k 6.12.0-211.7.1.el10_2, kernel-core 6.12.0-211.7.1.el10_2, kernel-tools 6.12.0-211.7.1.el10_2, kernel-modules 6.12.0-211.7.1.el10_2, kernel-64k-core 6.12.0-211.7.1.el10_2, +28 more
    fixed: vendor fix RHSA-2026:18134
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-687.31.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.31.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.31.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.31.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.31.1.el9_8
    fixed: vendor fix RHSA-2026:47040
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-211.7.1.el10_2, kernel-debuginfo-common-s390x 6.12.0-211.7.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.7.1.el10_2, kernel-debuginfo-common-aarch64 6.12.0-211.7.1.el10_2, kernel-debuginfo-common-ppc64le 6.12.0-211.7.1.el10_2
    fixed: vendor fix RHSA-2026:18134
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-687.31.1.el9_8, kernel-rt-64k 5.14.0-687.31.1.el9_8, kernel-rt-core 5.14.0-687.31.1.el9_8, kernel-rt-modules 5.14.0-687.31.1.el9_8, kernel-rt-64k-core 5.14.0-687.31.1.el9_8, kernel-rt-debug-core 5.14.0-687.31.1.el9_8, +14 more
    fixed: vendor fix RHSA-2026:47040
show 4 more
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-211.7.1.el10_2, kernel-rt-64k 6.12.0-211.7.1.el10_2, kernel-rt-core 6.12.0-211.7.1.el10_2, kernel-rt-modules 6.12.0-211.7.1.el10_2, kernel-rt-64k-core 6.12.0-211.7.1.el10_2, kernel-rt-debug-core 6.12.0-211.7.1.el10_2, +14 more
    fixed: vendor fix RHSA-2026:18134
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-687.31.1.el9_8, kernel-rt-core 5.14.0-687.31.1.el9_8, kernel-rt-modules 5.14.0-687.31.1.el9_8, kernel-rt-debug-core 5.14.0-687.31.1.el9_8, kernel-rt-modules-core 5.14.0-687.31.1.el9_8, kernel-rt-debug-modules 5.14.0-687.31.1.el9_8, +4 more
    fixed: vendor fix RHSA-2026:47040
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-211.7.1.el10_2, kernel-rt-core 6.12.0-211.7.1.el10_2, kernel-rt-modules 6.12.0-211.7.1.el10_2, kernel-rt-debug-core 6.12.0-211.7.1.el10_2, kernel-rt-modules-core 6.12.0-211.7.1.el10_2, kernel-rt-debug-modules 6.12.0-211.7.1.el10_2, +4 more
    fixed: vendor fix RHSA-2026:18134
  • 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 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 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
partial
Assessed
3 d ago

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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.