{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-90248", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.795Z", "datePublished": "2026-09-17T16:07:50.104Z", "dateUpdated": "2026-10-19T09:00:24.022Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:00:24.022Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: cls_api: fix teardown of an adopted proto on insert-race loss\n\nIn tc_new_tfilter() the create branch sets tp_created = 1 before calling\ntcf_chain_tp_insert_unique(). When the caller loses the race (another\nrequest inserted a proto at the same chain/prio first), insert_unique()\ndestroys the caller's own tp_new and returns the winner's proto with an\nextra reference. tp_created was never cleared, so the loser's errout\npath treated the winner's live proto as its own and called\ntcf_chain_tp_delete_empty() on it, silently unlinking an active\nclassifier that the winning request already advertised via\nRTM_NEWTFILTER.\n\nTrack the outcome of the insert step in a single tri-state variable so\neach errout path reacts correctly:\n\n- TP_NOT_CREATED: no proto created; pursue the old path.\n- TP_CREATED: proto inserted successfully; same code path as before.\n- TP_NOT_OWNED: New - lost the insert race; tp is another request's proto\n (chain ref already released by tp_new's destroy)\n\nBoth errout reactions are single expressions derived from the state.\n\nThis fix is motivated by the Sashiko's automated review of Patch\n(net/sched: cls_api: Always acquire rtnl_lock when destroying locked\nclassifiers) [1][2]. The review identified the silent-unlink behaviour of\nan adopted proto's teardown when a request loses the\ntcf_chain_tp_insert_unique() race.\n\n[1] https://sashiko.dev/#/patchset/20260801125632.360365-1-jhs%40mojatatu.com\n[2] https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260801125632.360365-1-jhs%40mojatatu.com" } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sched/cls_api.c" ], "versions": [ { "version": "8b64678e0af8f4d62a40149baedebe78503a5255", "lessThan": "a68e664ddf16ecae6d769d6a2eb356f8abab75c9", "status": "affected", "versionType": "git" }, { "version": "8b64678e0af8f4d62a40149baedebe78503a5255", "lessThan": "df02b6dc136af45e92ee4c86f4aa6c9a60790b1e", "status": "affected", "versionType": "git" }, { "version": "8b64678e0af8f4d62a40149baedebe78503a5255", "lessThan": "bee2208276c8e0e40a249ffdcf6e5434a79a847c", "status": "affected", "versionType": "git" }, { "version": "8b64678e0af8f4d62a40149baedebe78503a5255", "lessThan": "219c87aeefdcc8c1caf28cc99e9b361ce7393d3a", "status": "affected", "versionType": "git" }, { "version": "8b64678e0af8f4d62a40149baedebe78503a5255", "lessThan": "bbe2fd6d77df630356185406a97317f6aa6a92cf", "status": "affected", "versionType": "git" }, { "version": "8b64678e0af8f4d62a40149baedebe78503a5255", "lessThan": "dc8b33b819cb02a75936940c120aa669ad89942d", "status": "affected", "versionType": "git" }, { "version": "8b64678e0af8f4d62a40149baedebe78503a5255", "lessThan": "d4e359b3608a0e184bbe8d61a5c3b50d0831c44a", "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/sched/cls_api.c" ], "versions": [ { "version": "5.1", "status": "affected" }, { "version": "0", "lessThan": "5.1", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.221", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.188", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.110", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.52", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.6", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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": "5.1", "versionEndExcluding": "5.15.221" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.12.110" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.18.52" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "7.2.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/a68e664ddf16ecae6d769d6a2eb356f8abab75c9" }, { "url": "https://git.kernel.org/stable/c/df02b6dc136af45e92ee4c86f4aa6c9a60790b1e" }, { "url": "https://git.kernel.org/stable/c/bee2208276c8e0e40a249ffdcf6e5434a79a847c" }, { "url": "https://git.kernel.org/stable/c/219c87aeefdcc8c1caf28cc99e9b361ce7393d3a" }, { "url": "https://git.kernel.org/stable/c/bbe2fd6d77df630356185406a97317f6aa6a92cf" }, { "url": "https://git.kernel.org/stable/c/dc8b33b819cb02a75936940c120aa669ad89942d" }, { "url": "https://git.kernel.org/stable/c/d4e359b3608a0e184bbe8d61a5c3b50d0831c44a" } ], "title": "net/sched: cls_api: fix teardown of an adopted proto on insert-race loss", "x_generator": { "engine": "bippy-1.2.0" } } } }