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NVD / CVE Program· CNA Linux

CVE-2021-47460: ocfs2: fix data corruption after conversion from inline format

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.21% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 4.14.253, 4.19.214, 4.9.288.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 4.14.253, 4.19.214, 4.9.288 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix data corruption after conversion from inline format Commit 6dbf7bb55598 ("fs: Don't invalidate page buffers in block_write_full_page()") uncovered a latent bug in ocfs2 conversion from inline inode format to a normal inode format. The code in ocfs2_convert_inline_data_to_extents() attempts to zero out the whole cluster allocated for file data by grabbing, zeroing, and dirtying all pages covering this cluster. However these pages are beyond i_size, thus writeback code generally ignores these dirty pages and no blocks were ever actually zeroed on the disk. This oversight was fixed by commit 693c241a5f6a ("ocfs2: No need to zero pages past i_size.") for standard ocfs2 write path, inline conversion path was apparently forgotten; the commit log also has a reasoning why the zeroing actually is not needed. After commit 6dbf7bb55598, things became worse as writeback code stopped invalidating buffers on pages beyond i_size and thus these pages end up with clean PageDirty bit but with buffers attached to these pages being still dirty. So when a file is converted from inline format, then writeback triggers, and then the file is grown so that these pages become valid, the invalid dirtiness state is preserved, mark_buffer_dirty() does nothing on these pages (buffers are already dirty) but page is never written back because it is clean. So data written to these pages is lost once pages are reclaimed. Simple reproducer for the problem is: xfs_io -f -c "pwrite 0 2000" -c "pwrite 2000 2000" -c "fsync" \ -c "pwrite 4000 2000" ocfs2_file After unmounting and mounting the fs again, you can observe that end of 'ocfs2_file' has lost its contents. Fix the problem by not doing the pointless zeroing during conversion from inline format similarly as in the standard write path. [akpm@linux-foundation.org: fix whitespace, per Joseph]

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
May 22, 2024
Updated
Jun 17, 2026
EPSS
0.2% · 11th percentile
CWE
—

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

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  • when exploit code appears or is weaponized
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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel4.9.242 and later · before 4.9.288
  • linux linux kernel4.14.204 and later · before 4.14.253
  • linux linux kernel4.19.155 and later · before 4.19.214
  • linux linux kernel5.4.75 and later · before 5.4.156
  • linux linux kernel5.9.5 and later · before 5.10.76
  • linux linux kernel5.11 and later · before 5.14.15
  • linux linux kernel5.15

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 36ed9e604215f58cec0381ca5fcc6da05f2d87ca, 5.10affected
    • acef5107e2eacb08a16ad5db60320d65bd26a6c0 and later · before 560edd14de2bf9dbc0129681eeb4d5ef87cc105faffected · git
    • 7ed80e77c908cbaa686529a49f8ae0060c5caee7 and later · before 8e6bfb4f70168ddfd32fb6dc028ad52faaf1f32eaffected · git
    • 7ce2b16bad2cbfa3fa7bbc42c4448914f639ca47 and later · before a3a089c241cd49b33a8cdd7fcb37cc87a086912aaffected · git
    • f8a6a2ed4b7d1c3c8631eeb6d00572bc853094a8 and later · before b05caf023b14cbed9223bb5b48ecc7bffe38f632affected · git
    • 6dbf7bb555981fb5faf7b691e8f6169fc2b2e63b and later · before f1b98569e81c37d7e0deada7172f8f60860c1360affected · git
    • 6dbf7bb555981fb5faf7b691e8f6169fc2b2e63b and later · before fa9b6b6c953e3f6441ed6cf83b4c771dac2dae08affected · git
    • 6dbf7bb555981fb5faf7b691e8f6169fc2b2e63b and later · before 5314454ea3ff6fc746eaf71b9a7ceebed52888faaffected · git
    • 4.9.242 and later · before 4.9.288affected · semver
    • 4.14.204 and later · before 4.14.253affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 5.14.16-15.14.16-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2021-47458May 22, 2024 · ocfs2: mount fails with buffer overflow in strlen
    31Monitor
  • ← EarlierCVE-2021-47459May 22, 2024 · can: j1939: j1939_netdev_start(): fix UAF for rx_kref of j1939_priv
    31Monitor
  • Later →CVE-2021-47461May 22, 2024 · userfaultfd: fix a race between writeprotect and exit_mmap()
    18Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux4.14.253Vendor (CNA)
Linux Linux4.19.214Vendor (CNA)
Linux Linux4.9.288Vendor (CNA)
Linux Linux5.10Vendor (CNA)
Linux Linux5.4.156Vendor (CNA)
Linux Linux5314454ea3ff6fc746eaf71b9a7ceebed52888faVendor (CNA)
Linux Linux560edd14de2bf9dbc0129681eeb4d5ef87cc105fVendor (CNA)
Linux Linux8e6bfb4f70168ddfd32fb6dc028ad52faaf1f32eVendor (CNA)
Linux Linuxa3a089c241cd49b33a8cdd7fcb37cc87a086912aVendor (CNA)
Linux Linuxb05caf023b14cbed9223bb5b48ecc7bffe38f632Vendor (CNA)
Linux Linuxf1b98569e81c37d7e0deada7172f8f60860c1360Vendor (CNA)
Linux Linuxfa9b6b6c953e3f6441ed6cf83b4c771dac2dae08Vendor (CNA)
debian:linux5.14.16-1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (6 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records