iomap: guard io_size EOF trim against concurrent truncate underflow
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.
CVE-2026-72367
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-72367
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "82c59a86a247a8970d353d10f52a37e5564fb137",
"lessThan": "cc1d6af0bee27d6595908b497424f338161299fc",
"versionType": "git"
},
{
"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": "6.12.10",
"lessThan": "6.12.114",
"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": "6.12.114",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"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"
}
]- Related CVEs
- CVE-2026-72367
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #46511 · Revision 1
- Added to Heist Feed
- Publisher date