{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2025-68768", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-12-24T10:30:51.034Z", "datePublished": "2026-01-13T15:28:47.106Z", "dateUpdated": "2026-01-13T15:28:47.106Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-01-13T15:28:47.106Z"}, "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."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/net/inet_frag.h", "include/net/ipv6_frag.h", "net/ipv4/inet_fragment.c", "net/ipv4/ip_fragment.c"], "versions": [{"version": "d5dd88794a13c2f24cce31abad7a0a6c5e0ed2db", "lessThan": "c70df25214ac9b32b53e18e6ae3b8f073ffa6903", "status": "affected", "versionType": "git"}, {"version": "d5dd88794a13c2f24cce31abad7a0a6c5e0ed2db", "lessThan": "006a5035b495dec008805df249f92c22c89c3d2e", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/net/inet_frag.h", "include/net/ipv6_frag.h", "net/ipv4/inet_fragment.c", "net/ipv4/ip_fragment.c"], "versions": [{"version": "5.3", "status": "affected"}, {"version": "0", "lessThan": "5.3", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.3", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.19-rc2", "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": "5.3", "versionEndExcluding": "6.18.3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.3", "versionEndExcluding": "6.19-rc2"}]}]}], "references": [{"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"}}}}

{}

{"cveTags": [], "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."}], "id": "CVE-2025-68768", "lastModified": "2026-01-13T16:15:56.247", "metrics": {}, "published": "2026-01-13T16:15:56.247", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/006a5035b495dec008805df249f92c22c89c3d2e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/c70df25214ac9b32b53e18e6ae3b8f073ffa6903"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}

{}