{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64452", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.788Z", "datePublished": "2026-07-25T08:51:21.754Z", "dateUpdated": "2026-08-17T04:55:56.222Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:55:56.222Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\n6lowpan: fix NHC entry use-after-free on error path\n\nlowpan_nhc_do_uncompression() looks up an NHC descriptor while holding\nlowpan_nhc_lock. If the descriptor has no uncompress callback, the error\npath drops the lock before printing nhc->name.\n\nlowpan_nhc_del() removes descriptors under the same lock and then relies\non synchronize_net() before the owning module can be unloaded. That only\nwaits for net RX RCU readers. lowpan_header_decompress() is also exported\nand can be reached from callers that are not necessarily covered by the net\ncore RX critical section, for example the Bluetooth 6LoWPAN L2CAP receive\npath.\n\nThis leaves a race where one task drops lowpan_nhc_lock in the error path,\nanother task unregisters and frees the matching descriptor after\nsynchronize_net() returns, and the first task then dereferences nhc->name\nfor the warning.\n\nWith the post-unlock window widened, KASAN reports:\n\n BUG: KASAN: slab-use-after-free in lowpan_nhc_do_uncompression+0x1f4/0x220\n Read of size 8\n lowpan_nhc_do_uncompression\n lowpan_header_decompress\n\nFix this by printing the warning before dropping lowpan_nhc_lock, so the\ndescriptor name is read while unregister is still excluded. The malformed\npacket is still rejected with -ENOTSUPP." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 7.1, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:A - An adjacent Bluetooth LE peer can deliver a crafted IPHC/NHC frame through the unauthenticated L2CAP IPSP receive path to the vulnerable decompressor.\nAC:H - Exploitation requires the matching loadable NHC descriptor to be unregistered and freed during the tiny post-unlock window, and the adjacent attacker cannot independently force that module-unload side of the race.\nPR:N - The Bluetooth packet-processing path requires no attacker privileges or authenticated pairing because the IPSP channel uses BT_SECURITY_LOW; CAP_SYS_MODULE belongs to the victim-side unload actor.\nUI:R - Successful triggering requires a victim administrator or module-management action to unload the matching NHC module while the malicious packet is being processed.\nS:U - The vulnerability compromises the affected host kernel without crossing a separate virtualization, IOMMU, or security-authority boundary.\nC:H - The freed descriptor's name pointer is dereferenced as a string, so reused contents can cause an unbounded kernel-memory read and disclosure through the kernel log.\nI:H - As a kernel-space use-after-free, freed-object replacement is conservatively treated as potentially enabling memory-corruption or control-flow compromise.\nA:H - Dereferencing an invalid freed descriptor or string pointer can produce a kernel oops or panic and render the system unavailable." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/6lowpan/nhc.c" ], "versions": [ { "version": "92aa7c65d295f3cbb96904afe335f683e55584b8", "lessThan": "9c2f5c0829a8c8b904dae36be6d8056b719ac605", "status": "affected", "versionType": "git" }, { "version": "92aa7c65d295f3cbb96904afe335f683e55584b8", "lessThan": "80b5c8779acee0550845394fb3e5176a398aa24c", "status": "affected", "versionType": "git" }, { "version": "92aa7c65d295f3cbb96904afe335f683e55584b8", "lessThan": "cc27aea4d454abfb385ee2c9499c78b96db9b728", "status": "affected", "versionType": "git" }, { "version": "92aa7c65d295f3cbb96904afe335f683e55584b8", "lessThan": "a8e3a94711134e898c6021a6b77374efa91b3639", "status": "affected", "versionType": "git" }, { "version": "92aa7c65d295f3cbb96904afe335f683e55584b8", "lessThan": "593b78bb3c7ef0c6e9ae6fdf5afa80a5f7573168", "status": "affected", "versionType": "git" }, { "version": "92aa7c65d295f3cbb96904afe335f683e55584b8", "lessThan": "0beccbcf50de125be5520d0ffc59af4bb8655482", "status": "affected", "versionType": "git" }, { "version": "92aa7c65d295f3cbb96904afe335f683e55584b8", "lessThan": "b713aa0cc344f10f7a9928a230b5f5e780d04078", "status": "affected", "versionType": "git" }, { "version": "92aa7c65d295f3cbb96904afe335f683e55584b8", "lessThan": "1720db928e5a58ca7d75ac1d514c3b73fd7061a7", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/6lowpan/nhc.c" ], "versions": [ { "version": "4.1", "status": "affected" }, { "version": "0", "lessThan": "4.1", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.261", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.212", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.96", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.39", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.4", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "4.1", "versionEndExcluding": "5.10.261" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.1", "versionEndExcluding": "5.15.212" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.1", "versionEndExcluding": "6.1.178" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.1", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.1", "versionEndExcluding": "6.12.96" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.1", "versionEndExcluding": "6.18.39" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.1", "versionEndExcluding": "7.1.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.1", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/9c2f5c0829a8c8b904dae36be6d8056b719ac605" }, { "url": "https://git.kernel.org/stable/c/80b5c8779acee0550845394fb3e5176a398aa24c" }, { "url": "https://git.kernel.org/stable/c/cc27aea4d454abfb385ee2c9499c78b96db9b728" }, { "url": "https://git.kernel.org/stable/c/a8e3a94711134e898c6021a6b77374efa91b3639" }, { "url": "https://git.kernel.org/stable/c/593b78bb3c7ef0c6e9ae6fdf5afa80a5f7573168" }, { "url": "https://git.kernel.org/stable/c/0beccbcf50de125be5520d0ffc59af4bb8655482" }, { "url": "https://git.kernel.org/stable/c/b713aa0cc344f10f7a9928a230b5f5e780d04078" }, { "url": "https://git.kernel.org/stable/c/1720db928e5a58ca7d75ac1d514c3b73fd7061a7" } ], "title": "6lowpan: fix NHC entry use-after-free on error path", "x_generator": { "engine": "bippy-1.2.0" } } } }