{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-97959", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:18:58.205Z", "datePublished": "2026-09-25T10:23:04.348Z", "dateUpdated": "2026-10-19T09:11:25.255Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:11:25.255Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: cls_route: free emptied bucket on filter move\n\nroute4_change can move an existing filter to a different top-level\nbucket: route4_set_parms recomputes the handle from TCA_ROUTE4_TO/\nFROM/IIF, and the handle-mismatch check is gated on the 'new' flag, so\nfor an existing filter the new handle may differ from the old one and\nland in a different bucket. When this happens, the filter is unlinked\nfrom the old bucket, but the bucket itself is never freed once it goes\nempty. The stale empty bucket remains in head->table[], causing\nroute4_delete to report *last=false even after the last live filter is\ngone. That pins the empty tcf_proto and causes a leak.\n\nFix this by refcounting the filters linked to a bucket and freeing the\nbucket when the count drops to zero. The existing scan in route4_delete\ngoes away with it.\n\nThe count is updated at all sites that link or unlink a filter during add,\nchange and delete, and the bucket is dropped from head->table[] as soon as\nit reaches zero.\n\nConditions to recreate the bug:\n CONFIG_NET_CLS_ROUTE4=y, CONFIG_NET_SCH_INGRESS=y, CONFIG_NET_CLS_ACT=y.\n\n tc qdisc replace dev lo clsact\n tc filter add dev lo ingress protocol ip pref 100 route from 1 to 1\n tc filter change dev lo ingress protocol ip pref 100 handle 0x10001 \\\n route from 1 to 2\n tc filter del dev lo ingress protocol ip pref 100 handle 0x10002 \\\n route from 1 to 2\n tc filter show dev lo ingress | grep -c 'pref 100 route chain 0 '" } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sched/cls_route.c" ], "versions": [ { "version": "1e052be69d045c8d0f82ff1116fd3e5a79661745", "lessThan": "9e7741b41a25b9d49df4d262fa314342e6f95c50", "status": "affected", "versionType": "git" }, { "version": "1e052be69d045c8d0f82ff1116fd3e5a79661745", "lessThan": "48d38bf8c22a05fde07ba1f885cde27b851649a2", "status": "affected", "versionType": "git" }, { "version": "1e052be69d045c8d0f82ff1116fd3e5a79661745", "lessThan": "cc99d26b12431e4e4d0e346ec32764eb42c0aed9", "status": "affected", "versionType": "git" }, { "version": "1e052be69d045c8d0f82ff1116fd3e5a79661745", "lessThan": "41e94079200aaf0cdbe4594b0af75710b33da124", "status": "affected", "versionType": "git" }, { "version": "1e052be69d045c8d0f82ff1116fd3e5a79661745", "lessThan": "2e2f130951d34871b0643bf700164d97cff4b427", "status": "affected", "versionType": "git" }, { "version": "1e052be69d045c8d0f82ff1116fd3e5a79661745", "lessThan": "f8495d67434e1cb7e511297687ca55fdb28e4c20", "status": "affected", "versionType": "git" }, { "version": "1e052be69d045c8d0f82ff1116fd3e5a79661745", "lessThan": "81dd117c04422c6d0c7974aba9fa6a0ba370959b", "status": "affected", "versionType": "git" }, { "version": "1e052be69d045c8d0f82ff1116fd3e5a79661745", "lessThan": "1853f30cf5c84971f99788a76207c6f745380896", "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_route.c" ], "versions": [ { "version": "4.1", "status": "affected" }, { "version": "0", "lessThan": "4.1", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.271", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.222", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.189", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.158", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.111", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.53", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.7", "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": "4.1", "versionEndExcluding": "5.10.271" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.1", "versionEndExcluding": "5.15.222" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.1", "versionEndExcluding": "6.1.189" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.1", "versionEndExcluding": "6.6.158" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.1", "versionEndExcluding": "6.12.111" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.1", "versionEndExcluding": "6.18.53" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.1", "versionEndExcluding": "7.2.7" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.1", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/9e7741b41a25b9d49df4d262fa314342e6f95c50" }, { "url": "https://git.kernel.org/stable/c/48d38bf8c22a05fde07ba1f885cde27b851649a2" }, { "url": "https://git.kernel.org/stable/c/cc99d26b12431e4e4d0e346ec32764eb42c0aed9" }, { "url": "https://git.kernel.org/stable/c/41e94079200aaf0cdbe4594b0af75710b33da124" }, { "url": "https://git.kernel.org/stable/c/2e2f130951d34871b0643bf700164d97cff4b427" }, { "url": "https://git.kernel.org/stable/c/f8495d67434e1cb7e511297687ca55fdb28e4c20" }, { "url": "https://git.kernel.org/stable/c/81dd117c04422c6d0c7974aba9fa6a0ba370959b" }, { "url": "https://git.kernel.org/stable/c/1853f30cf5c84971f99788a76207c6f745380896" } ], "title": "net/sched: cls_route: free emptied bucket on filter move", "x_generator": { "engine": "bippy-1.2.0" } } } }