CVE-2026-72225

In the Linux kernel, the following vulnerability has been resolved: jbd2: fix integer underflow in jbd2_journal_initialize_fast_commit() jbd2_journal_initialize_fast_commit() validates journal capacity by checking (journal->j_last - num_fc_blks < JBD2_MIN_JOURNAL_BLOCKS). Both j_last and num_fc_blks are unsigned, so when num_fc_blks exceeds j_last the subtraction wraps to a large value, bypassing the bounds check. The resulting underflow corrupts j_last, j_fc_first, and j_free, leading to journal abort. Fix by checking num_fc_blks against j_last before the subtraction, returning -EFSCORRUPTED.

CVSS v3 7.8 HIGH

7.8^/10

CVSS v3 : HIGH

Vector :

Exploitability : 1.8 / Impact : 5.9

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://git.kernel.org/stable/c/289a2ca0c9b7eae74f93fc213b0b971669b8683d
https://git.kernel.org/stable/c/4450dcaadf7d4aae8b6e4223b5d6ee4eb77097a9
https://git.kernel.org/stable/c/4b48dcb88bb9117e3d3f051175a9a8b7cff7f8b6
https://git.kernel.org/stable/c/78955fdce8ff654e6d33a2fa90882a1e7eb26330
https://git.kernel.org/stable/c/a58fc10adf503969fec2007b5afe8987258046c4
https://git.kernel.org/stable/c/aa90f00932bf572d6ef284c977c2a60b39c13bd6
https://git.kernel.org/stable/c/e144ad0250f77e23e28949587b8b57e40dc3b512
https://git.kernel.org/stable/c/fb9b49618ed7296ebfad62a3835da8945f727001

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-15 06:21

Updated : 2026-08-23 13:16

NVD link : CVE-2026-72225

Mitre link : CVE-2026-72225

CVE.ORG link : CVE-2026-72225

JSON object : View

Products Affected

No product.

CWE

No CWE.

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num_fc_blks < JBD2_MIN_JOURNAL_BLOCKS).\nBoth j_last and num_fc_blks are unsigned, so when num_fc_blks exceeds\nj_last the subtraction wraps to a large value, bypassing the bounds\ncheck.\n\nThe resulting underflow corrupts j_last, j_fc_first, and j_free,\nleading to journal abort.\n\nFix by checking num_fc_blks against j_last before the subtraction,\nreturning -EFSCORRUPTED."}], "lastModified": "2026-08-23T13:16:41.947", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}