{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-63892", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T07:54:57.019Z", "datePublished": "2026-07-19T14:55:03.568Z", "dateUpdated": "2026-07-19T14:55:03.568Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-07-19T14:55:03.568Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nthunderbolt: property: Reject dir_len < 4 to prevent size_t underflow\n\nOn the non-root path, __tb_property_parse_dir() takes dir_len from\nentry->length (u16 widened to size_t). Two distinct OOB conditions\nfollow when entry->length < 4:\n\n1. The non-root path begins with kmemdup(&block[dir_offset],\n sizeof(*dir->uuid), ...) which always reads 4 dwords from\n dir_offset. tb_property_entry_valid() only enforces\n dir_offset + entry->length <= block_len, so a crafted entry\n with dir_offset close to the end of the property block and\n entry->length in 0..3 passes that gate but lets the UUID copy\n run off the block (e.g. dir_offset = 497, dir_len = 3 in a\n 500-dword block reads block[497..501]).\n\n2. After the kmemdup, content_len = dir_len - 4 underflows size_t\n to ~SIZE_MAX, nentries becomes SIZE_MAX / 4, and the entry\n walk runs OOB on each iteration until an entry fails\n validation or the kernel oopses on an unmapped page.\n\nReject dir_len < 4 on the non-root path *before* the UUID kmemdup,\nwhich closes both holes.\n\nAlso move INIT_LIST_HEAD(&dir->properties) up to immediately after\nthe dir allocation so the new error-return path (and the existing\nuuid-alloc failure path) calling tb_property_free_dir() sees a\nwalkable list rather than the zero-initialized NULL next/prev that\nlist_for_each_entry_safe() would oops on." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/thunderbolt/property.c" ], "versions": [ { "version": "cdae7c07e3e3509eaabc18c1640a55dc5b99c179", "lessThan": "37abc4504fa19d8f9f1e87792e8a2b8fdb308e40", "status": "affected", "versionType": "git" }, { "version": "cdae7c07e3e3509eaabc18c1640a55dc5b99c179", "lessThan": "e2d4d51cf5785815fa4e91e0c019e3eb2506a84c", "status": "affected", "versionType": "git" }, { "version": "cdae7c07e3e3509eaabc18c1640a55dc5b99c179", "lessThan": "de618299190b418291609e6921557253bd417e25", "status": "affected", "versionType": "git" }, { "version": "cdae7c07e3e3509eaabc18c1640a55dc5b99c179", "lessThan": "5506c825f14d810f0690b1f4367cb7249ebb387a", "status": "affected", "versionType": "git" }, { "version": "cdae7c07e3e3509eaabc18c1640a55dc5b99c179", "lessThan": "542a13890b742099c461d70920e97b14e568f6ec", "status": "affected", "versionType": "git" }, { "version": "cdae7c07e3e3509eaabc18c1640a55dc5b99c179", "lessThan": "d548179adcc87e1bc66b17e00352a1f536e76065", "status": "affected", "versionType": "git" }, { "version": "cdae7c07e3e3509eaabc18c1640a55dc5b99c179", "lessThan": "3bec49ca55e08fb085cc4318f24b1b37eaab28cb", "status": "affected", "versionType": "git" }, { "version": "cdae7c07e3e3509eaabc18c1640a55dc5b99c179", "lessThan": "de21b59c29e31c5108ddc04210631bbfab81b997", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/thunderbolt/property.c" ], "versions": [ { "version": "4.15", "status": "affected" }, { "version": "0", "lessThan": "4.15", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.259", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.210", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.176", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.143", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.93", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.35", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.12", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.15", "versionEndExcluding": "5.10.259" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.15", "versionEndExcluding": "5.15.210" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.15", "versionEndExcluding": "6.1.176" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.15", "versionEndExcluding": "6.6.143" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.15", "versionEndExcluding": "6.12.93" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.15", "versionEndExcluding": "6.18.35" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.15", "versionEndExcluding": "7.0.12" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.15", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/37abc4504fa19d8f9f1e87792e8a2b8fdb308e40" }, { "url": "https://git.kernel.org/stable/c/e2d4d51cf5785815fa4e91e0c019e3eb2506a84c" }, { "url": "https://git.kernel.org/stable/c/de618299190b418291609e6921557253bd417e25" }, { "url": "https://git.kernel.org/stable/c/5506c825f14d810f0690b1f4367cb7249ebb387a" }, { "url": "https://git.kernel.org/stable/c/542a13890b742099c461d70920e97b14e568f6ec" }, { "url": "https://git.kernel.org/stable/c/d548179adcc87e1bc66b17e00352a1f536e76065" }, { "url": "https://git.kernel.org/stable/c/3bec49ca55e08fb085cc4318f24b1b37eaab28cb" }, { "url": "https://git.kernel.org/stable/c/de21b59c29e31c5108ddc04210631bbfab81b997" } ], "title": "thunderbolt: property: Reject dir_len < 4 to prevent size_t underflow", "x_generator": { "engine": "bippy-1.2.0" } } } }