{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2025-68241", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2025-68241", "idYear": 2025, "status": "PUBLISHED", "publishedAt": "2025-12-16T14:21:18.682Z", "updatedAt": "2026-08-05T12:10:24.792Z", "importedAt": "2026-10-24T01:57:44.935Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "ipv4: route: Prevent rt_bind_exception() from rebinding stale fnhe", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv4: route: Prevent rt_bind_exception() from rebinding stale fnhe\n\nThe sit driver's packet transmission path calls: sit_tunnel_xmit() ->\nupdate_or_create_fnhe(), which lead to fnhe_remove_oldest() being called\nto delete entries exceeding FNHE_RECLAIM_DEPTH+random.\n\nThe race window is between fnhe_remove_oldest() selecting fnheX for\ndeletion and the subsequent kfree_rcu(). During this time, the\nconcurrent path's __mkroute_output() -> find_exception() can fetch the\nsoon-to-be-deleted fnheX, and rt_bind_exception() then binds it with a\nnew dst using a dst_hold(). When the original fnheX is freed via RCU,\nthe dst reference remains permanently leaked.\n\nCPU 0 CPU 1\n__mkroute_output()\n find_exception() [fnheX]\n update_or_create_fnhe()\n fnhe_remove_oldest() [fnheX]\n rt_bind_exception() [bind dst]\n RCU callback [fnheX freed, dst leak]\n\nThis issue manifests as a device reference count leak and a warning in\ndmesg when unregistering the net device:\n\n unregister_netdevice: waiting for sitX to become free. Usage count = N\n\nIdo Schimmel provided the simple test validation method [1].\n\nThe fix clears 'oldest->fnhe_daddr' before calling fnhe_flush_routes().\nSince rt_bind_exception() checks this field, setting it to zero prevents\nthe stale fnhe from being reused and bound to a new dst just before it\nis freed.\n\n[1]\nip netns add ns1\nip -n ns1 link set dev lo up\nip -n ns1 address add 192.0.2.1/32 dev lo\nip -n ns1 link add name dummy1 up type dummy\nip -n ns1 route add 192.0.2.2/32 dev dummy1\nip -n ns1 link add name gretap1 up arp off type gretap \\\n local 192.0.2.1 remote 192.0.2.2\nip -n ns1 route add 198.51.0.0/16 dev gretap1\ntaskset -c 0 ip netns exec ns1 mausezahn gretap1 \\\n -A 198.51.100.1 -B 198.51.0.0/16 -t udp -p 1000 -c 0 -q &\ntaskset -c 2 ip netns exec ns1 mausezahn gretap1 \\\n -A 198.51.100.1 -B 198.51.0.0/16 -t udp -p 1000 -c 0 -q &\nsleep 10\nip netns pids ns1 | xargs kill\nip netns del ns1", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "e46e23c289f62ccd8e2230d9ce652072d777ff30", "status": "affected", "versionType": "git", "lessThan": "69d35c12168f9c59b159ae566f77dfad9f96d7ca" }, { "version": "5867e20e1808acd0c832ddea2587e5ee49813874", "status": "affected", "versionType": "git", "lessThan": "4b7210da22429765d19460d38c30eeca72656282" }, { "version": "67d6d681e15b578c1725bad8ad079e05d1c48a8e", "status": "affected", "versionType": "git", "lessThan": "298f1e0694ab4edb6092d66efed93c4554e6ced1" }, { "version": "67d6d681e15b578c1725bad8ad079e05d1c48a8e", "status": "affected", "versionType": "git", "lessThan": "b8a44407bdaf2f0c5505cc7d9fc7d8da90cf9a94" }, { "version": "67d6d681e15b578c1725bad8ad079e05d1c48a8e", "status": "affected", "versionType": "git", "lessThan": "041ab9ca6e80d8f792bb69df28ebf1ef39c06af8" }, { "version": "67d6d681e15b578c1725bad8ad079e05d1c48a8e", "status": "affected", "versionType": "git", "lessThan": "b84f083f50ecc736a95091691339a1b363962f0e" }, { "version": "67d6d681e15b578c1725bad8ad079e05d1c48a8e", "status": "affected", "versionType": "git", "lessThan": "0fd16ed6dc331636fb2a874c42d2f7d3156f7ff0" }, { "version": "67d6d681e15b578c1725bad8ad079e05d1c48a8e", "status": "affected", "versionType": "git", "lessThan": "ac1499fcd40fe06479e9b933347b837ccabc2a40" }, { "version": "bed8941fbdb72a61f6348c4deb0db69c4de87aca", "status": "affected", "versionType": "git" }, { "version": "f10ce783bcc4d8ea454563a7d56ae781640e7dcb", "status": "affected", "versionType": "git" }, { "version": "f484595be6b7ef9d095a32becabb5dae8204fb2a", "status": "affected", "versionType": "git" }, { "version": "3e6bd2b583f18da9856fc9741ffa200a74a52cba", "status": "affected", "versionType": "git" }, { "version": "5ae06218331f39ec45b5d039aa7cb3ddd4bb8008", "status": "affected", "versionType": "git" }, { "version": "4589a12dcf80af31137ef202be1ff4a321707a73", "status": "affected", "versionType": "git" }, { "version": "5.4.146", "status": "affected", "versionType": "semver", "lessThan": "5.4.302" }, { "version": "5.10.65", "status": "affected", "versionType": "semver", "lessThan": "5.10.247" }, { "version": "4.4.284", "status": "affected", "versionType": "semver", "lessThan": "4.5" }, { "version": "4.9.283", "status": "affected", "versionType": "semver", "lessThan": "4.10" }, { "version": "4.14.247", "status": "affected", "versionType": "semver", "lessThan": "4.15" }, { "version": "4.19.207", "status": "affected", "versionType": "semver", "lessThan": "4.20" }, { "version": "5.13.17", "status": "affected", "versionType": "semver", "lessThan": "5.14" }, { "version": "5.14.4", "status": "affected", "versionType": "semver", "lessThan": "5.15" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "5.15", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "5.15" }, { "version": "5.4.302", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.4.*" }, { "version": "5.10.247", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.10.*" }, { "version": "5.15.197", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.15.*" }, { "version": "6.1.159", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.1.*" }, { "version": "6.6.117", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.12.59", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.17.9", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.17.*" }, { "version": "6.18", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }