{"api_version":"1","generated_at":"2026-07-23T12:19:00+00:00","cve":"CVE-2025-68768","urls":{"html":"https://cve.report/CVE-2025-68768","api":"https://cve.report/api/cve/CVE-2025-68768.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2025-68768","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-68768"},"summary":{"title":"inet: frags: flush pending skbs in fqdir_pre_exit()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ninet: frags: flush pending skbs in fqdir_pre_exit()\n\nWe have been seeing occasional deadlocks on pernet_ops_rwsem since\nSeptember in NIPA. The stuck task was usually modprobe (often loading\na driver like ipvlan), trying to take the lock as a Writer.\nlockdep does not track readers for rwsems so the read wasn't obvious\nfrom the reports.\n\nOn closer inspection the Reader holding the lock was conntrack looping\nforever in nf_conntrack_cleanup_net_list(). Based on past experience\nwith occasional NIPA crashes I looked thru the tests which run before\nthe crash and noticed that the crash follows ip_defrag.sh. An immediate\nred flag. Scouring thru (de)fragmentation queues reveals skbs sitting\naround, holding conntrack references.\n\nThe problem is that since conntrack depends on nf_defrag_ipv6,\nnf_defrag_ipv6 will load first. Since nf_defrag_ipv6 loads first its\nnetns exit hooks run _after_ conntrack's netns exit hook.\n\nFlush all fragment queue SKBs during fqdir_pre_exit() to release\nconntrack references before conntrack cleanup runs. Also flush\nthe queues in timer expiry handlers when they discover fqdir->dead\nis set, in case packet sneaks in while we're running the pre_exit\nflush.\n\nThe commit under Fixes is not exactly the culprit, but I think\npreviously the timer firing would eventually unblock the spinning\nconntrack.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-01-13 16:15:56","updated_at":"2026-06-19 13:16:24"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/c70df25214ac9b32b53e18e6ae3b8f073ffa6903","name":"https://git.kernel.org/stable/c/c70df25214ac9b32b53e18e6ae3b8f073ffa6903","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/543555954b1ee8d1903a7020324efb41b0c97428","name":"https://git.kernel.org/stable/c/543555954b1ee8d1903a7020324efb41b0c97428","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/006a5035b495dec008805df249f92c22c89c3d2e","name":"https://git.kernel.org/stable/c/006a5035b495dec008805df249f92c22c89c3d2e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/22ee4010866da81aeee08e1ea3fddbe418feb212","name":"https://git.kernel.org/stable/c/22ee4010866da81aeee08e1ea3fddbe418feb212","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2025-68768","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-68768","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d5dd88794a13c2f24cce31abad7a0a6c5e0ed2db 22ee4010866da81aeee08e1ea3fddbe418feb212 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d5dd88794a13c2f24cce31abad7a0a6c5e0ed2db 543555954b1ee8d1903a7020324efb41b0c97428 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d5dd88794a13c2f24cce31abad7a0a6c5e0ed2db c70df25214ac9b32b53e18e6ae3b8f073ffa6903 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d5dd88794a13c2f24cce31abad7a0a6c5e0ed2db 006a5035b495dec008805df249f92c22c89c3d2e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.3","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.3 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.143 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.93 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.3 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.19 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2025","cve_id":"68768","cve":"CVE-2025-68768","epss":"0.001680000","percentile":"0.063520000","score_date":"2026-06-24","updated_at":"2026-06-25 00:05:30"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["include/net/inet_frag.h","include/net/ipv6_frag.h","net/ipv4/inet_fragment.c","net/ipv4/ip_fragment.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"22ee4010866da81aeee08e1ea3fddbe418feb212","status":"affected","version":"d5dd88794a13c2f24cce31abad7a0a6c5e0ed2db","versionType":"git"},{"lessThan":"543555954b1ee8d1903a7020324efb41b0c97428","status":"affected","version":"d5dd88794a13c2f24cce31abad7a0a6c5e0ed2db","versionType":"git"},{"lessThan":"c70df25214ac9b32b53e18e6ae3b8f073ffa6903","status":"affected","version":"d5dd88794a13c2f24cce31abad7a0a6c5e0ed2db","versionType":"git"},{"lessThan":"006a5035b495dec008805df249f92c22c89c3d2e","status":"affected","version":"d5dd88794a13c2f24cce31abad7a0a6c5e0ed2db","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["include/net/inet_frag.h","include/net/ipv6_frag.h","net/ipv4/inet_fragment.c","net/ipv4/ip_fragment.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.3"},{"lessThan":"5.3","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.143","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.93","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.3","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"6.19","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.143","versionStartIncluding":"5.3","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.93","versionStartIncluding":"5.3","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.3","versionStartIncluding":"5.3","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.19","versionStartIncluding":"5.3","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ninet: frags: flush pending skbs in fqdir_pre_exit()\n\nWe have been seeing occasional deadlocks on pernet_ops_rwsem since\nSeptember in NIPA. The stuck task was usually modprobe (often loading\na driver like ipvlan), trying to take the lock as a Writer.\nlockdep does not track readers for rwsems so the read wasn't obvious\nfrom the reports.\n\nOn closer inspection the Reader holding the lock was conntrack looping\nforever in nf_conntrack_cleanup_net_list(). Based on past experience\nwith occasional NIPA crashes I looked thru the tests which run before\nthe crash and noticed that the crash follows ip_defrag.sh. An immediate\nred flag. Scouring thru (de)fragmentation queues reveals skbs sitting\naround, holding conntrack references.\n\nThe problem is that since conntrack depends on nf_defrag_ipv6,\nnf_defrag_ipv6 will load first. Since nf_defrag_ipv6 loads first its\nnetns exit hooks run _after_ conntrack's netns exit hook.\n\nFlush all fragment queue SKBs during fqdir_pre_exit() to release\nconntrack references before conntrack cleanup runs. Also flush\nthe queues in timer expiry handlers when they discover fqdir->dead\nis set, in case packet sneaks in while we're running the pre_exit\nflush.\n\nThe commit under Fixes is not exactly the culprit, but I think\npreviously the timer firing would eventually unblock the spinning\nconntrack."}],"providerMetadata":{"dateUpdated":"2026-06-19T11:57:29.047Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/22ee4010866da81aeee08e1ea3fddbe418feb212"},{"url":"https://git.kernel.org/stable/c/543555954b1ee8d1903a7020324efb41b0c97428"},{"url":"https://git.kernel.org/stable/c/c70df25214ac9b32b53e18e6ae3b8f073ffa6903"},{"url":"https://git.kernel.org/stable/c/006a5035b495dec008805df249f92c22c89c3d2e"}],"title":"inet: frags: flush pending skbs in fqdir_pre_exit()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2025-68768","datePublished":"2026-01-13T15:28:47.106Z","dateReserved":"2025-12-24T10:30:51.034Z","dateUpdated":"2026-06-19T11:57:29.047Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-01-13 16:15:56","lastModifiedDate":"2026-06-19 13:16:24","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2025","CveId":"68768","Ordinal":"1","Title":"inet: frags: flush pending skbs in fqdir_pre_exit()","CVE":"CVE-2025-68768","Year":"2025"},"notes":[{"CveYear":"2025","CveId":"68768","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\ninet: frags: flush pending skbs in fqdir_pre_exit()\n\nWe have been seeing occasional deadlocks on pernet_ops_rwsem since\nSeptember in NIPA. The stuck task was usually modprobe (often loading\na driver like ipvlan), trying to take the lock as a Writer.\nlockdep does not track readers for rwsems so the read wasn't obvious\nfrom the reports.\n\nOn closer inspection the Reader holding the lock was conntrack looping\nforever in nf_conntrack_cleanup_net_list(). Based on past experience\nwith occasional NIPA crashes I looked thru the tests which run before\nthe crash and noticed that the crash follows ip_defrag.sh. An immediate\nred flag. Scouring thru (de)fragmentation queues reveals skbs sitting\naround, holding conntrack references.\n\nThe problem is that since conntrack depends on nf_defrag_ipv6,\nnf_defrag_ipv6 will load first. Since nf_defrag_ipv6 loads first its\nnetns exit hooks run _after_ conntrack's netns exit hook.\n\nFlush all fragment queue SKBs during fqdir_pre_exit() to release\nconntrack references before conntrack cleanup runs. Also flush\nthe queues in timer expiry handlers when they discover fqdir->dead\nis set, in case packet sneaks in while we're running the pre_exit\nflush.\n\nThe commit under Fixes is not exactly the culprit, but I think\npreviously the timer firing would eventually unblock the spinning\nconntrack.","Type":"Description","Title":"inet: frags: flush pending skbs in fqdir_pre_exit()"}]}}}