Skip to content
Fencer Vulns
medium 5.5

CVE-2022-50428 json

ext4: fix off-by-one errors in fast-commit block filling

published 2025-10-01 13 mo ago modified 2026-11-05 3 d ago also EUVD-2025-32857

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 5%
public exploits
0
none known

Summary

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

ext4: fix off-by-one errors in fast-commit block filling

Due to several different off-by-one errors, or perhaps due to a late change in design that wasn't fully reflected in the code that was actually merged, there are several very strange constraints on how fast-commit blocks are filled with tlv entries:

- tlvs must start at least 10 bytes before the end of the block, even though the minimum tlv length is 8. Otherwise, the replay code will ignore them. (BUG: ext4_fc_reserve_space() could violate this requirement if called with a len of blocksize - 9 or blocksize - 8. Fortunately, this doesn't seem to happen currently.)

- tlvs must end at least 1 byte before the end of the block. Otherwise the replay code will consider them to be invalid. This quirk contributed to a bug (fixed by an earlier commit) where uninitialized memory was being leaked to disk in the last byte of blocks.

Also, strangely these constraints don't apply to the replay code in e2fsprogs, which will accept any tlvs in the blocks (with no bounds checks at all, but that is a separate issue...).

Given that this all seems to be a bug, let's fix it by just filling blocks with tlv entries in the natural way.

Note that old kernels will be unable to replay fast-commit journals created by kernels that have this commit.

Patch / fix

  • Linux Linux 5.15.87, 6.0.18, 6.1.4, 6.2
  • linux Debian 14, Debian 13, Debian 12 6.1.4-1

debian advisories DEBIAN-CVE-2022-50428

  • linux Ubuntu 22.04 LTS 5.15.0-69.76
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1033.37
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1031.38
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1030.35
  • linux-ibm Ubuntu 22.04 LTS 5.15.0-1027.30
  • linux-kvm Ubuntu 22.04 LTS 5.15.0-1030.35
  • linux-azure Ubuntu 22.04 LTS 5.15.0-1035.42
  • linux-gkeop Ubuntu 22.04 LTS 5.15.0-1017.22

ubuntu advisories UBUNTU-CVE-2022-50428

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 SLE Micro 5.5 5.14.21-150500.13.109.1
  • kernel-source-rt SLE Micro 5.5 5.14.21-150500.13.109.1
  • kernel-rt SLE Micro 5.4, SLE Micro 5.3 5.14.21-150400.15.133.1
  • kernel-source-rt SLE Micro 5.4, SLE Micro 5.3 5.14.21-150400.15.133.1
  • kernel-64kb SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS, SLE High Performance Computing 15 SP4-ESPOS 5.14.21-150400.24.179.1
  • kernel-syms SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +3 more 5.14.21-150400.24.179.1
  • kernel-source SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +3 more 5.14.21-150400.24.179.1
  • kernel-default SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +7 more 5.14.21-150400.24.179.1

suse advisories SUSE-SU-2025:3761-1SUSE-SU-2025:3716-1SUSE-SU-2025:03628-1SUSE-SU-2025:03615-1

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-2022-50428 updated cvss 6.1

kernel: ext4: fix off-by-one errors in fast-commit block filling

  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    affected: no fix available “Fix deferred”
  • 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 Red Hat Enterprise Linux 10 kernel
    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

0.16% chance of exploitation in the next 30 days, higher than 5% 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.