Skip to content
Fencer Vulns
medium 5.5

CVE-2026-23199 json

procfs: avoid fetching build ID while holding VMA lock

published 2026-02-14 8 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-5848

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 0%
public exploits
0
none known

Summary

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

procfs: avoid fetching build ID while holding VMA lock

Fix PROCMAP_QUERY to fetch optional build ID only after dropping mmap_lock or per-VMA lock, whichever was used to lock VMA under question, to avoid deadlock reported by syzbot:

-> #1 (&mm->mmap_lock){++++}-{4:4}: __might_fault+0xed/0x170 _copy_to_iter+0x118/0x1720 copy_page_to_iter+0x12d/0x1e0 filemap_read+0x720/0x10a0 blkdev_read_iter+0x2b5/0x4e0 vfs_read+0x7f4/0xae0 ksys_read+0x12a/0x250 do_syscall_64+0xcb/0xf80 entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&sb->s_type->i_mutex_key#8){++++}-{4:4}: __lock_acquire+0x1509/0x26d0 lock_acquire+0x185/0x340 down_read+0x98/0x490 blkdev_read_iter+0x2a7/0x4e0 __kernel_read+0x39a/0xa90 freader_fetch+0x1d5/0xa80 __build_id_parse.isra.0+0xea/0x6a0 do_procmap_query+0xd75/0x1050 procfs_procmap_ioctl+0x7a/0xb0 __x64_sys_ioctl+0x18e/0x210 do_syscall_64+0xcb/0xf80 entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Possible unsafe locking scenario:

CPU0 CPU1 ---- ---- rlock(&mm->mmap_lock); lock(&sb->s_type->i_mutex_key#8); lock(&mm->mmap_lock); rlock(&sb->s_type->i_mutex_key#8);

*** DEADLOCK ***

This seems to be exacerbated (as we haven't seen these syzbot reports before that) by the recent:

777a8560fd29 ("lib/buildid: use __kernel_read() for sleepable context")

To make this safe, we need to grab file refcount while VMA is still locked, but other than that everything is pretty straightforward. Internal build_id_parse() API assumes VMA is passed, but it only needs the underlying file reference, so just add another variant build_id_parse_file() that expects file passed directly.

[akpm@linux-foundation.org: fix up kerneldoc]

Patch / fix

  • Linux Linux 6.12.70, 6.18.10, 6.19
  • linux Debian 13 6.12.73-1
  • linux Debian 14 6.18.10-1

debian advisories DEBIAN-CVE-2026-23199

  • kernel RHEL 10.2 6.12.0-211.43.1.el10_2
  • rv RHEL 10.2 6.12.0-211.43.1.el10_2
  • perf RHEL 10.2 6.12.0-211.43.1.el10_2
  • rtla RHEL 10.2 6.12.0-211.43.1.el10_2
  • libperf RHEL 10.2 6.12.0-211.43.1.el10_2
  • kernel-rt RHEL 10.2 6.12.0-211.43.1.el10_2
  • kernel-64k RHEL 10.2 6.12.0-211.43.1.el10_2
  • kernel-core RHEL 10.2 6.12.0-211.43.1.el10_2

red hat advisories RHSA-2026:49871

  • kernel-default SLES 16.0, SLE High Availability Extension 16.0, Linux Micro 6.2 +1 more 6.12.0-160000.39.1
  • kernel-rt Linux Micro 6.2 6.12.0-160000.39.1
  • kernel-64kb SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.39.1
  • kernel-source SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.39.1
  • kernel-default-base SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.39.1.160000.2.26
  • kernel-syms SLES 16.0, Linux Micro Extras 6.2, SLES for SAP applications 16.0 6.12.0-160000.39.1
  • kernel-azure SLES for SAP applications 16.0, SLES 16.0 6.12.0-160000.39.1
  • kernel-obs-qa SLES for SAP applications 16.0, SLES 16.0 6.12.0-160000.39.1

suse advisories SUSE-SU-2026:24197-1SUSE-SU-2026:24184-1SUSE-SU-2026:24235-1SUSE-SU-2026:24179-1

  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.39.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.39.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.39.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.39.1
  • kernel-azure openSUSE Leap 16.0 6.12.0-160000.39.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.39.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.39.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.39.1

opensuse advisories openSUSE-SU-2026:22091-1

  • kernel AlmaLinux 10 6.12.0-211.43.1.el10_2
  • rv AlmaLinux 10 6.12.0-211.43.1.el10_2
  • perf AlmaLinux 10 6.12.0-211.43.1.el10_2
  • rtla AlmaLinux 10 6.12.0-211.43.1.el10_2
  • libperf AlmaLinux 10 6.12.0-211.43.1.el10_2
  • kernel-rt AlmaLinux 10 6.12.0-211.43.1.el10_2
  • kernel-64k AlmaLinux 10 6.12.0-211.43.1.el10_2
  • kernel-core AlmaLinux 10 6.12.0-211.43.1.el10_2

almalinux advisories ALSA-2026:49871

  • kernel Rocky Linux 10 6.12.0-211.43.1.el10_2

rocky linux advisories RLSA-2026:49871

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-2026-23199 updated cvss 5.5

kernel: procfs: avoid fetching build ID while holding VMA lock

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-211.43.1.el10_2, perf 6.12.0-211.43.1.el10_2, rtla 6.12.0-211.43.1.el10_2, python3-perf 6.12.0-211.43.1.el10_2, kernel-devel-matched 6.12.0-211.43.1.el10_2, kernel-64k-devel-matched 6.12.0-211.43.1.el10_2, +7 more
    fixed: vendor fix RHSA-2026:49871
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) rv 6.12.0-55.113.1.el10_0, perf 6.12.0-55.113.1.el10_0, rtla 6.12.0-55.113.1.el10_0, python3-perf 6.12.0-55.113.1.el10_0, kernel-devel-matched 6.12.0-55.113.1.el10_0, kernel-64k-devel-matched 6.12.0-55.113.1.el10_0, +7 more
    fixed: vendor fix RHSA-2026:88687
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-211.43.1.el10_2, kernel-64k 6.12.0-211.43.1.el10_2, kernel-core 6.12.0-211.43.1.el10_2, kernel-tools 6.12.0-211.43.1.el10_2, kernel-modules 6.12.0-211.43.1.el10_2, kernel-64k-core 6.12.0-211.43.1.el10_2, +28 more
    fixed: vendor fix RHSA-2026:49871
  • Red Hat Enterprise Linux BaseOS EUS (v. 10.0) kernel 6.12.0-55.113.1.el10_0, kernel-64k 6.12.0-55.113.1.el10_0, kernel-core 6.12.0-55.113.1.el10_0, kernel-tools 6.12.0-55.113.1.el10_0, kernel-modules 6.12.0-55.113.1.el10_0, kernel-64k-core 6.12.0-55.113.1.el10_0, +27 more
    fixed: vendor fix RHSA-2026:88687
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-211.43.1.el10_2, kernel-debuginfo-common-s390x 6.12.0-211.43.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.43.1.el10_2, kernel-debuginfo-common-aarch64 6.12.0-211.43.1.el10_2, kernel-debuginfo-common-ppc64le 6.12.0-211.43.1.el10_2
    fixed: vendor fix RHSA-2026:49871
  • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) libperf 6.12.0-55.113.1.el10_0, kernel-debuginfo-common-s390x 6.12.0-55.113.1.el10_0, kernel-debuginfo-common-x86_64 6.12.0-55.113.1.el10_0, kernel-debuginfo-common-aarch64 6.12.0-55.113.1.el10_0, kernel-debuginfo-common-ppc64le 6.12.0-55.113.1.el10_0
    fixed: vendor fix RHSA-2026:88687
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-211.43.1.el10_2, kernel-rt-64k 6.12.0-211.43.1.el10_2, kernel-rt-core 6.12.0-211.43.1.el10_2, kernel-rt-modules 6.12.0-211.43.1.el10_2, kernel-rt-64k-core 6.12.0-211.43.1.el10_2, kernel-rt-debug-core 6.12.0-211.43.1.el10_2, +14 more
    fixed: vendor fix RHSA-2026:49871
show 4 more
  • Red Hat Enterprise Linux Real Time EUS (v. 10.0) kernel-rt 6.12.0-55.113.1.el10_0, kernel-rt-64k 6.12.0-55.113.1.el10_0, kernel-rt-core 6.12.0-55.113.1.el10_0, kernel-rt-modules 6.12.0-55.113.1.el10_0, kernel-rt-64k-core 6.12.0-55.113.1.el10_0, kernel-rt-debug-core 6.12.0-55.113.1.el10_0, +14 more
    fixed: vendor fix RHSA-2026:88687
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-211.43.1.el10_2, kernel-rt-core 6.12.0-211.43.1.el10_2, kernel-rt-modules 6.12.0-211.43.1.el10_2, kernel-rt-debug-core 6.12.0-211.43.1.el10_2, kernel-rt-modules-core 6.12.0-211.43.1.el10_2, kernel-rt-debug-modules 6.12.0-211.43.1.el10_2, +4 more
    fixed: vendor fix RHSA-2026:49871
  • Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0) kernel-rt 6.12.0-55.113.1.el10_0, kernel-rt-kvm 6.12.0-55.113.1.el10_0, kernel-rt-core 6.12.0-55.113.1.el10_0, kernel-rt-modules 6.12.0-55.113.1.el10_0, kernel-rt-debug-kvm 6.12.0-55.113.1.el10_0, kernel-rt-debug-core 6.12.0-55.113.1.el10_0, +6 more
    fixed: vendor fix RHSA-2026:88687
  • 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 Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 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

Exploit prediction

0.10% chance of exploitation in the next 30 days, higher than 0% 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.