{"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":"2026-09-17T16:07:50.104Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-17T16:07:50.104Z"},"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-rc1","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-rc1"}]}]}],"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"}}}}