{"id":"CVE-2026-64452","state":"PUBLISHED","title":"6lowpan: fix NHC entry use-after-free on error path","description":"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.","publishedAt":"2026-07-25T08:51:21.754Z","updatedAt":"2026-10-19T20:38:30.450Z","severity":{"score":7.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"92aa7c65d295f3cbb96904afe335f683e55584b8","status":"affected","lessThan":"9c2f5c0829a8c8b904dae36be6d8056b719ac605","versionType":"git"},{"version":"92aa7c65d295f3cbb96904afe335f683e55584b8","status":"affected","lessThan":"80b5c8779acee0550845394fb3e5176a398aa24c","versionType":"git"},{"version":"92aa7c65d295f3cbb96904afe335f683e55584b8","status":"affected","lessThan":"cc27aea4d454abfb385ee2c9499c78b96db9b728","versionType":"git"},{"version":"92aa7c65d295f3cbb96904afe335f683e55584b8","status":"affected","lessThan":"a8e3a94711134e898c6021a6b77374efa91b3639","versionType":"git"},{"version":"92aa7c65d295f3cbb96904afe335f683e55584b8","status":"affected","lessThan":"593b78bb3c7ef0c6e9ae6fdf5afa80a5f7573168","versionType":"git"},{"version":"92aa7c65d295f3cbb96904afe335f683e55584b8","status":"affected","lessThan":"0beccbcf50de125be5520d0ffc59af4bb8655482","versionType":"git"},{"version":"92aa7c65d295f3cbb96904afe335f683e55584b8","status":"affected","lessThan":"b713aa0cc344f10f7a9928a230b5f5e780d04078","versionType":"git"},{"version":"92aa7c65d295f3cbb96904afe335f683e55584b8","status":"affected","lessThan":"1720db928e5a58ca7d75ac1d514c3b73fd7061a7","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/6lowpan/nhc.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.1","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.1","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.96","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/6lowpan/nhc.c"]}],"references":["https://git.kernel.org/stable/c/9c2f5c0829a8c8b904dae36be6d8056b719ac605","https://git.kernel.org/stable/c/80b5c8779acee0550845394fb3e5176a398aa24c","https://git.kernel.org/stable/c/cc27aea4d454abfb385ee2c9499c78b96db9b728","https://git.kernel.org/stable/c/a8e3a94711134e898c6021a6b77374efa91b3639","https://git.kernel.org/stable/c/593b78bb3c7ef0c6e9ae6fdf5afa80a5f7573168","https://git.kernel.org/stable/c/0beccbcf50de125be5520d0ffc59af4bb8655482","https://git.kernel.org/stable/c/b713aa0cc344f10f7a9928a230b5f5e780d04078","https://git.kernel.org/stable/c/1720db928e5a58ca7d75ac1d514c3b73fd7061a7"],"weaknesses":["CWE-416"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64452.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64452","state":"PUBLISHED","datePublished":"2026-07-25T08:51:21.754Z","dateUpdated":"2026-10-19T20:38:30.450Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T15:36:31.788Z"},"containers":{"cna":{"title":"6lowpan: fix NHC entry use-after-free on error path","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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"92aa7c65d295f3cbb96904afe335f683e55584b8","status":"affected","lessThan":"9c2f5c0829a8c8b904dae36be6d8056b719ac605","versionType":"git"},{"version":"92aa7c65d295f3cbb96904afe335f683e55584b8","status":"affected","lessThan":"80b5c8779acee0550845394fb3e5176a398aa24c","versionType":"git"},{"version":"92aa7c65d295f3cbb96904afe335f683e55584b8","status":"affected","lessThan":"cc27aea4d454abfb385ee2c9499c78b96db9b728","versionType":"git"},{"version":"92aa7c65d295f3cbb96904afe335f683e55584b8","status":"affected","lessThan":"a8e3a94711134e898c6021a6b77374efa91b3639","versionType":"git"},{"version":"92aa7c65d295f3cbb96904afe335f683e55584b8","status":"affected","lessThan":"593b78bb3c7ef0c6e9ae6fdf5afa80a5f7573168","versionType":"git"},{"version":"92aa7c65d295f3cbb96904afe335f683e55584b8","status":"affected","lessThan":"0beccbcf50de125be5520d0ffc59af4bb8655482","versionType":"git"},{"version":"92aa7c65d295f3cbb96904afe335f683e55584b8","status":"affected","lessThan":"b713aa0cc344f10f7a9928a230b5f5e780d04078","versionType":"git"},{"version":"92aa7c65d295f3cbb96904afe335f683e55584b8","status":"affected","lessThan":"1720db928e5a58ca7d75ac1d514c3b73fd7061a7","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/6lowpan/nhc.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.1","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.1","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.96","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/6lowpan/nhc.c"]}],"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"}],"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."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T04:55:56.222Z"},"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"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-64452","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:41:07.187657Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-416","lang":"en","type":"CWE","description":"CWE-416 Use After Free"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:38:30.450Z"}}]}}}