CVE-2026-72367
iomap: guard io_size EOF trim against concurrent truncate underflow
Description
In the Linux kernel, the following vulnerability has been resolved: iomap: guard io_size EOF trim against concurrent truncate underflow iomap: fix zero padding data issue in concurrent append writes changed ioend accounting so that io_size tracks only valid data within EOF. This trims io_size when a writeback range extends past end_pos: ioend->io_size += map_len; if (ioend->io_offset + ioend->io_size > end_pos) ioend->io_size = end_pos - ioend->io_offset; However, if end_pos ends up below ioend->io_offset, the subtraction becomes negative and is stored in size_t io_size, causing an unsigned wrap to a huge value. This can happen when writeback continues past byte-level EOF up to a block-aligned range, or when a concurrent truncate shrinks the file after end_pos was sampled in iomap_writeback_handle_eof(). A wrapped io_size can mislead append detection and corrupt completion-time size handling, since filesystem end_io paths consume io_size for decisions such as on-disk EOF updates and unwritten/COW completion ranges. Fix this by clamping io_size to zero when EOF has moved to or before the ioend start offset. This preserves the original intent of trimming io_size to valid in-EOF data while avoiding the underflow.
INFO
Published Date :
Aug. 15, 2026, 6:22 a.m.
Last Modified :
Aug. 17, 2026, 6:18 a.m.
Remotely Exploit :
Yes !
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Update the Linux kernel to the latest stable version.
- Apply the specific patch for the iomap EOF trim issue.
- Verify the system is running the corrected kernel version.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-72367.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-72367 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-72367
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-72367 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-72367 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 17, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Changed Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '51d20d1dacbec589d459e11fc88fbca419f84a99', 'lessThan': '1f38f65bf965fce9aa159d45c5347538f56c5973', 'versionType': 'git'}, {'status': 'affected', 'version': '51d20d1dacbec589d459e11fc88fbca419f84a99', 'lessThan': '7f7780abb4c0fdc9a2603aea8e985ff14ee900e0', 'versionType': 'git'}, {'status': 'affected', 'version': '51d20d1dacbec589d459e11fc88fbca419f84a99', 'lessThan': '55ec50d046c03b3724741957f7b007856e36dbe7', 'versionType': 'git'}, {'status': 'affected', 'version': '82c59a86a247a8970d353d10f52a37e5564fb137', 'versionType': 'git'}, {'status': 'affected', 'version': '6.12.10', 'lessThan': '6.13', 'versionType': 'semver'}], 'programFiles': ['fs/iomap/ioend.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.13'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.13', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.18.40', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.5', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['fs/iomap/ioend.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '51d20d1dacbec589d459e11fc88fbca419f84a99', 'lessThan': '1f38f65bf965fce9aa159d45c5347538f56c5973', 'versionType': 'git'}, {'status': 'affected', 'version': '51d20d1dacbec589d459e11fc88fbca419f84a99', 'lessThan': '7f7780abb4c0fdc9a2603aea8e985ff14ee900e0', 'versionType': 'git'}, {'status': 'affected', 'version': '51d20d1dacbec589d459e11fc88fbca419f84a99', 'lessThan': '55ec50d046c03b3724741957f7b007856e36dbe7', 'versionType': 'git'}, {'status': 'affected', 'version': '82c59a86a247a8970d353d10f52a37e5564fb137', 'versionType': 'git'}, {'status': 'affected', 'version': '6.12.10', 'lessThan': '6.13', 'versionType': 'semver'}], 'programFiles': ['fs/iomap/ioend.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.13'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.13', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.18.40', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.5', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['fs/iomap/ioend.c'], 'defaultStatus': 'affected'}] -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 15, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '51d20d1dacbec589d459e11fc88fbca419f84a99', 'lessThan': '1f38f65bf965fce9aa159d45c5347538f56c5973', 'versionType': 'git'}, {'status': 'affected', 'version': '51d20d1dacbec589d459e11fc88fbca419f84a99', 'lessThan': '7f7780abb4c0fdc9a2603aea8e985ff14ee900e0', 'versionType': 'git'}, {'status': 'affected', 'version': '51d20d1dacbec589d459e11fc88fbca419f84a99', 'lessThan': '55ec50d046c03b3724741957f7b007856e36dbe7', 'versionType': 'git'}, {'status': 'affected', 'version': '82c59a86a247a8970d353d10f52a37e5564fb137', 'versionType': 'git'}, {'status': 'affected', 'version': '6.12.10', 'lessThan': '6.13', 'versionType': 'semver'}], 'programFiles': ['fs/iomap/ioend.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.13'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.13', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.18.40', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.5', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['fs/iomap/ioend.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: iomap: guard io_size EOF trim against concurrent truncate underflow iomap: fix zero padding data issue in concurrent append writes changed ioend accounting so that io_size tracks only valid data within EOF. This trims io_size when a writeback range extends past end_pos: ioend->io_size += map_len; if (ioend->io_offset + ioend->io_size > end_pos) ioend->io_size = end_pos - ioend->io_offset; However, if end_pos ends up below ioend->io_offset, the subtraction becomes negative and is stored in size_t io_size, causing an unsigned wrap to a huge value. This can happen when writeback continues past byte-level EOF up to a block-aligned range, or when a concurrent truncate shrinks the file after end_pos was sampled in iomap_writeback_handle_eof(). A wrapped io_size can mislead append detection and corrupt completion-time size handling, since filesystem end_io paths consume io_size for decisions such as on-disk EOF updates and unwritten/COW completion ranges. Fix this by clamping io_size to zero when EOF has moved to or before the ioend start offset. This preserves the original intent of trimming io_size to valid in-EOF data while avoiding the underflow. Added Reference https://git.kernel.org/stable/c/1f38f65bf965fce9aa159d45c5347538f56c5973 Added Reference https://git.kernel.org/stable/c/55ec50d046c03b3724741957f7b007856e36dbe7 Added Reference https://git.kernel.org/stable/c/7f7780abb4c0fdc9a2603aea8e985ff14ee900e0