FKIE_CVE-2026-53165
Vulnerability from fkie_nvd - Published: 2026-06-25 09:16 - Updated: 2026-06-30 14:44
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
iomap: avoid potential null folio->mapping deref during error reporting
When a buffered read fails, iomap_finish_folio_read() reports the error
with fserror_report_io(folio->mapping->host, ...). This is called after
ifs->read_bytes_pending has been decremented by the bytes attempted to
be read.
For a folio split across multiple read completions, the folio is only
guaranteed to stay locked while read_bytes_pending > 0. Once
iomap_finish_folio_read() decrements read_bytes_pending, another
in-flight read can complete and end the read on the folio, which unlocks
it. This allows truncate logic to run and detach the folio (set
folio->mapping to NULL). The error reporting path then can dereference a
NULL folio->mapping. As reported by Sam Sun, this is the race that can
occur:
CPU0: failed completion CPU1: final completion CPU2: truncate
----------------------- ---------------------- --------------
read_bytes_pending -= len
finished = false
/* preempted before
fserror_report_io() */
read_bytes_pending -= len
finished = true
folio_end_read()
truncate clears
folio->mapping
fserror_report_io(
folio->mapping->host, ...)
^ NULL deref
Fix this by reporting the error first before decrementing
ifs->read_bytes_pending.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/iomap/buffered-io.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "1ad453817a4077230d1ba88eb0868f05f824449a",
"status": "affected",
"version": "a9d573ee88af980f14fdadb5c12bbf6a195fb3f1",
"versionType": "git"
},
{
"lessThan": "2eea7f44b9c8b42fd7d3a1a87c06a7cd1b99c327",
"status": "affected",
"version": "a9d573ee88af980f14fdadb5c12bbf6a195fb3f1",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"fs/iomap/buffered-io.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "7.0"
},
{
"lessThan": "7.0",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.0.*",
"status": "unaffected",
"version": "7.0.13",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\niomap: avoid potential null folio-\u003emapping deref during error reporting\n\nWhen a buffered read fails, iomap_finish_folio_read() reports the error\nwith fserror_report_io(folio-\u003emapping-\u003ehost, ...). This is called after\nifs-\u003eread_bytes_pending has been decremented by the bytes attempted to\nbe read.\n\nFor a folio split across multiple read completions, the folio is only\nguaranteed to stay locked while read_bytes_pending \u003e 0. Once\niomap_finish_folio_read() decrements read_bytes_pending, another\nin-flight read can complete and end the read on the folio, which unlocks\nit. This allows truncate logic to run and detach the folio (set\nfolio-\u003emapping to NULL). The error reporting path then can dereference a\nNULL folio-\u003emapping. As reported by Sam Sun, this is the race that can\noccur:\n\nCPU0: failed completion CPU1: final completion CPU2: truncate\n----------------------- ---------------------- --------------\nread_bytes_pending -= len\nfinished = false\n/* preempted before\n fserror_report_io() */\n\t\t\t read_bytes_pending -= len\n\t\t\t finished = true\n\t\t\t folio_end_read()\n\t\t\t\t\t\t\ttruncate clears\n\t\t\t\t\t\t\tfolio-\u003emapping\nfserror_report_io(\n folio-\u003emapping-\u003ehost, ...)\n\t ^ NULL deref\n\nFix this by reporting the error first before decrementing\nifs-\u003eread_bytes_pending."
}
],
"id": "CVE-2026-53165",
"lastModified": "2026-06-30T14:44:27.313",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 7.5,
"baseSeverity": "HIGH",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"exploitabilityScore": 3.9,
"impactScore": 3.6,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2026-06-25T09:16:33.893",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/1ad453817a4077230d1ba88eb0868f05f824449a"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/2eea7f44b9c8b42fd7d3a1a87c06a7cd1b99c327"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Awaiting Analysis"
}
Loading…
Loading…
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Loading…
Loading…