FKIE_CVE-2026-64322
Vulnerability from fkie_nvd - Published: 2026-07-25 10:17 - Updated: 2026-07-27 05:16
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
udf: validate sparing table length as an entry count, not a byte count
udf_load_sparable_map() accepts a sparing table when
sizeof(*st) + le16_to_cpu(st->reallocationTableLen) > sb->s_blocksize
is false, i.e. it treats reallocationTableLen as a number of BYTES that
must fit in the block. But the table is walked as an array of 8-byte
sparingEntry elements:
for (i = 0; i < le16_to_cpu(st->reallocationTableLen); i++) {
struct sparingEntry *entry = &st->mapEntry[i];
... entry->origLocation ...
}
in udf_get_pblock_spar15() and udf_relocate_blocks(). A
reallocationTableLen of N therefore passes the check whenever
sizeof(*st) + N <= blocksize, yet the consumers index
sizeof(*st) + N * sizeof(struct sparingEntry) bytes -- up to ~8x the
block. On a crafted UDF image this is an out-of-bounds read in
udf_get_pblock_spar15(); udf_relocate_blocks() additionally feeds the
same length to udf_update_tag(), whose crc_itu_t() reads far past the
block, and its memmove() through st->mapEntry[] is an out-of-bounds
write.
Validate reallocationTableLen as the entry count it is, with
struct_size().
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/udf/super.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "eeb0f3e193f8e523d03e4c9e084f6b4875f50e8e",
"status": "affected",
"version": "1df2ae31c724e57be9d7ac00d78db8a5dabdd050",
"versionType": "git"
},
{
"lessThan": "0a9b79a951cfd70a9d31ca01ae2d08a20bb730e9",
"status": "affected",
"version": "1df2ae31c724e57be9d7ac00d78db8a5dabdd050",
"versionType": "git"
},
{
"lessThan": "2d726135099313958f8975532a2e15322ff150ce",
"status": "affected",
"version": "1df2ae31c724e57be9d7ac00d78db8a5dabdd050",
"versionType": "git"
},
{
"lessThan": "7285276aa50d2839afb5957ffd491ad282dc8f72",
"status": "affected",
"version": "1df2ae31c724e57be9d7ac00d78db8a5dabdd050",
"versionType": "git"
},
{
"lessThan": "2a219acb2ce674d99bbd1b7b35ed8c384dac7200",
"status": "affected",
"version": "1df2ae31c724e57be9d7ac00d78db8a5dabdd050",
"versionType": "git"
},
{
"lessThan": "04f4599a9efb90992d072a814960edf0cd62805d",
"status": "affected",
"version": "1df2ae31c724e57be9d7ac00d78db8a5dabdd050",
"versionType": "git"
},
{
"lessThan": "7f7774b9da0ef17b87bfa238cf966ad0b3376150",
"status": "affected",
"version": "1df2ae31c724e57be9d7ac00d78db8a5dabdd050",
"versionType": "git"
},
{
"lessThan": "3ec997bd5508e9b25210b5bbec89031629cdb093",
"status": "affected",
"version": "1df2ae31c724e57be9d7ac00d78db8a5dabdd050",
"versionType": "git"
},
{
"status": "affected",
"version": "e240873cb4a9fd18de60a817100a96fe670d4359",
"versionType": "git"
},
{
"status": "affected",
"version": "9ae30e324a96d0328a575329d7a95a09b3318601",
"versionType": "git"
},
{
"status": "affected",
"version": "b1c5701ad6b3e5d21d16f65475651cfaaa41e7aa",
"versionType": "git"
},
{
"status": "affected",
"version": "a9f1af04f086656246f30354fb4564ce3b08c4a0",
"versionType": "git"
},
{
"status": "affected",
"version": "4836ee563d65bb492f907cbe267a5761b9693e4d",
"versionType": "git"
},
{
"lessThan": "2.6.33",
"status": "affected",
"version": "2.6.32.60",
"versionType": "semver"
},
{
"lessThan": "2.6.35",
"status": "affected",
"version": "2.6.34.14",
"versionType": "semver"
},
{
"lessThan": "3.1",
"status": "affected",
"version": "3.0.37",
"versionType": "semver"
},
{
"lessThan": "3.3",
"status": "affected",
"version": "3.2.23",
"versionType": "semver"
},
{
"lessThan": "3.5",
"status": "affected",
"version": "3.4.5",
"versionType": "semver"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"fs/udf/super.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "3.5"
},
{
"lessThan": "3.5",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.261",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.212",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.96",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.39",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.4",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2-rc1",
"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\nudf: validate sparing table length as an entry count, not a byte count\n\nudf_load_sparable_map() accepts a sparing table when\n\n\tsizeof(*st) + le16_to_cpu(st-\u003ereallocationTableLen) \u003e sb-\u003es_blocksize\n\nis false, i.e. it treats reallocationTableLen as a number of BYTES that\nmust fit in the block. But the table is walked as an array of 8-byte\nsparingEntry elements:\n\n\tfor (i = 0; i \u003c le16_to_cpu(st-\u003ereallocationTableLen); i++) {\n\t\tstruct sparingEntry *entry = \u0026st-\u003emapEntry[i];\n\t\t... entry-\u003eorigLocation ...\n\t}\n\nin udf_get_pblock_spar15() and udf_relocate_blocks(). A\nreallocationTableLen of N therefore passes the check whenever\nsizeof(*st) + N \u003c= blocksize, yet the consumers index\nsizeof(*st) + N * sizeof(struct sparingEntry) bytes -- up to ~8x the\nblock. On a crafted UDF image this is an out-of-bounds read in\nudf_get_pblock_spar15(); udf_relocate_blocks() additionally feeds the\nsame length to udf_update_tag(), whose crc_itu_t() reads far past the\nblock, and its memmove() through st-\u003emapEntry[] is an out-of-bounds\nwrite.\n\nValidate reallocationTableLen as the entry count it is, with\nstruct_size()."
}
],
"id": "CVE-2026-64322",
"lastModified": "2026-07-27T05:16:42.210",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2026-07-25T10:17:13.640",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/04f4599a9efb90992d072a814960edf0cd62805d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/0a9b79a951cfd70a9d31ca01ae2d08a20bb730e9"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/2a219acb2ce674d99bbd1b7b35ed8c384dac7200"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/2d726135099313958f8975532a2e15322ff150ce"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/3ec997bd5508e9b25210b5bbec89031629cdb093"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/7285276aa50d2839afb5957ffd491ad282dc8f72"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/7f7774b9da0ef17b87bfa238cf966ad0b3376150"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/eeb0f3e193f8e523d03e4c9e084f6b4875f50e8e"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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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.
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