{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2025-68241", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-12-16T13:41:40.263Z", "datePublished": "2025-12-16T14:21:18.682Z", "dateUpdated": "2025-12-16T14:21:18.682Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2025-12-16T14:21:18.682Z"}, "descriptions": [{"lang": "en", "value": "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": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/ipv4/route.c"], "versions": [{"version": "e46e23c289f62ccd8e2230d9ce652072d777ff30", "lessThan": "69d35c12168f9c59b159ae566f77dfad9f96d7ca", "status": "affected", "versionType": "git"}, {"version": "5867e20e1808acd0c832ddea2587e5ee49813874", "lessThan": "4b7210da22429765d19460d38c30eeca72656282", "status": "affected", "versionType": "git"}, {"version": "67d6d681e15b578c1725bad8ad079e05d1c48a8e", "lessThan": "298f1e0694ab4edb6092d66efed93c4554e6ced1", "status": "affected", "versionType": "git"}, {"version": "67d6d681e15b578c1725bad8ad079e05d1c48a8e", "lessThan": "b8a44407bdaf2f0c5505cc7d9fc7d8da90cf9a94", "status": "affected", "versionType": "git"}, {"version": "67d6d681e15b578c1725bad8ad079e05d1c48a8e", "lessThan": "041ab9ca6e80d8f792bb69df28ebf1ef39c06af8", "status": "affected", "versionType": "git"}, {"version": "67d6d681e15b578c1725bad8ad079e05d1c48a8e", "lessThan": "b84f083f50ecc736a95091691339a1b363962f0e", "status": "affected", "versionType": "git"}, {"version": "67d6d681e15b578c1725bad8ad079e05d1c48a8e", "lessThan": "0fd16ed6dc331636fb2a874c42d2f7d3156f7ff0", "status": "affected", "versionType": "git"}, {"version": "67d6d681e15b578c1725bad8ad079e05d1c48a8e", "lessThan": "ac1499fcd40fe06479e9b933347b837ccabc2a40", "status": "affected", "versionType": "git"}, {"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"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/ipv4/route.c"], "versions": [{"version": "5.15", "status": "affected"}, {"version": "0", "lessThan": "5.15", "status": "unaffected", "versionType": "semver"}, {"version": "5.4.302", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.247", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.197", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.159", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.117", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.59", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.17.9", "lessThanOrEqual": "6.17.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18", "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": "5.4.146", "versionEndExcluding": "5.4.302"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10.65", "versionEndExcluding": "5.10.247"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "5.15.197"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.1.159"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.6.117"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.12.59"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.17.9"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.18"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.4.284"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9.283"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14.247"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.19.207"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13.17"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14.4"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/69d35c12168f9c59b159ae566f77dfad9f96d7ca"}, {"url": "https://git.kernel.org/stable/c/4b7210da22429765d19460d38c30eeca72656282"}, {"url": "https://git.kernel.org/stable/c/298f1e0694ab4edb6092d66efed93c4554e6ced1"}, {"url": "https://git.kernel.org/stable/c/b8a44407bdaf2f0c5505cc7d9fc7d8da90cf9a94"}, {"url": "https://git.kernel.org/stable/c/041ab9ca6e80d8f792bb69df28ebf1ef39c06af8"}, {"url": "https://git.kernel.org/stable/c/b84f083f50ecc736a95091691339a1b363962f0e"}, {"url": "https://git.kernel.org/stable/c/0fd16ed6dc331636fb2a874c42d2f7d3156f7ff0"}, {"url": "https://git.kernel.org/stable/c/ac1499fcd40fe06479e9b933347b837ccabc2a40"}], "title": "ipv4: route: Prevent rt_bind_exception() from rebinding stale fnhe", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "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"}], "id": "CVE-2025-68241", "lastModified": "2025-12-16T15:15:53.283", "metrics": {}, "published": "2025-12-16T15:15:53.283", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/041ab9ca6e80d8f792bb69df28ebf1ef39c06af8"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/0fd16ed6dc331636fb2a874c42d2f7d3156f7ff0"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/298f1e0694ab4edb6092d66efed93c4554e6ced1"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/4b7210da22429765d19460d38c30eeca72656282"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/69d35c12168f9c59b159ae566f77dfad9f96d7ca"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/ac1499fcd40fe06479e9b933347b837ccabc2a40"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b84f083f50ecc736a95091691339a1b363962f0e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b8a44407bdaf2f0c5505cc7d9fc7d8da90cf9a94"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}

{}