{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2022-49110", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-02-26T01:49:39.251Z", "datePublished": "2025-02-26T01:54:55.998Z", "dateUpdated": "2026-08-05T08:53:56.214Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:53:56.214Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: conntrack: revisit gc autotuning\n\nas of commit 4608fdfc07e1\n(\"netfilter: conntrack: collect all entries in one cycle\")\nconntrack gc was changed to run every 2 minutes.\n\nOn systems where conntrack hash table is set to large value, most evictions\nhappen from gc worker rather than the packet path due to hash table\ndistribution.\n\nThis causes netlink event overflows when events are collected.\n\nThis change collects average expiry of scanned entries and\nreschedules to the average remaining value, within 1 to 60 second interval.\n\nTo avoid event overflows, reschedule after each bucket and add a\nlimit for both run time and number of evictions per run.\n\nIf more entries have to be evicted, reschedule and restart 1 jiffy\ninto the future." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - nf_conntrack on internet-facing firewalls, NAT gateways, and Kubernetes nodes creates entries from unauthenticated transit/ingress packets (nf_conntrack_in → init_conntrack); a remote peer flooding unique tuples drives the expired-entry backlog that the flawed gc_worker then mass-evicts.\nAC:L - The attacker controls flow creation rate and expiry timing (e.g. unreplied UDP at the default 30s timeout), and large conntrack hash tables plus ctnetlink listeners (conntrackd) are normal firewall deployments rather than rare attacker-uncontrollable conditions.\nPR:N - Conntrack insertion and later GC eviction are side effects of packet processing with no authentication or host credentials; the attacker needs no local account or capability on the gateway.\nUI:N - Packet-driven conntrack creation and the periodic gc_worker run without any victim user action such as opening a file or mounting a filesystem.\nS:U - Event overflows, dying_list backlog, and table-full packet drops remain inside the same kernel networking authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:N - This is a scheduling/resource issue with no out-of-bounds read, UAF reclaim, or other primitive that discloses kernel or connection memory to the attacker.\nI:N - There is no memory corruption, arbitrary write, or control-flow hijack; lost ctnetlink events and delayed frees do not yield an integrity primitive against kernel state.\nA:H - Delayed reclaim leaves expired entries counted in cnet->count so the table hits nf_conntrack_max and drops legitimate traffic; burst GC without an eviction cap floods DESTROY events (ENOBUFS, dying_list memory hold) and can peg CPU via next_run=0 reschedules, denying firewall/NAT availability." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/netfilter/nf_conntrack_core.c" ], "versions": [ { "version": "4608fdfc07e116f9fc0895beb40abad7cdb5ee3d", "lessThan": "58d52743ae85d28c9335c6034d6ce350b8689951", "status": "affected", "versionType": "git" }, { "version": "4608fdfc07e116f9fc0895beb40abad7cdb5ee3d", "lessThan": "7cd361d5e6d986c0d4cafb9ceaa803359048ae15", "status": "affected", "versionType": "git" }, { "version": "4608fdfc07e116f9fc0895beb40abad7cdb5ee3d", "lessThan": "592e57591826f3d09c28d755a39ea8e9d13705ad", "status": "affected", "versionType": "git" }, { "version": "4608fdfc07e116f9fc0895beb40abad7cdb5ee3d", "lessThan": "2cfadb761d3d0219412fd8150faea60c7e863833", "status": "affected", "versionType": "git" }, { "version": "dafc95a1e473a0b857af34ecbb17b8b1c90edd75", "status": "affected", "versionType": "git" }, { "version": "5892f910f401c1facfc410e0b042108f2827a77b", "status": "affected", "versionType": "git" }, { "version": "f68ad168e23565ce2a3891fec537cfaf8410d1e6", "status": "affected", "versionType": "git" }, { "version": "7aa03980b21fdc7355e20274a68a69a0b2a45c08", "status": "affected", "versionType": "git" }, { "version": "4.19.206", "lessThan": "4.20", "status": "affected", "versionType": "semver" }, { "version": "5.4.144", "lessThan": "5.5", "status": "affected", "versionType": "semver" }, { "version": "5.10.62", "lessThan": "5.11", "status": "affected", "versionType": "semver" }, { "version": "5.13.14", "lessThan": "5.14", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/netfilter/nf_conntrack_core.c" ], "versions": [ { "version": "5.14", "status": "affected" }, { "version": "0", "lessThan": "5.14", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.34", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.16.20", "lessThanOrEqual": "5.16.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.17.3", "lessThanOrEqual": "5.17.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.18", "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": "5.14", "versionEndExcluding": "5.15.34" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "5.16.20" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "5.17.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "5.18" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.19.206" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4.144" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10.62" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13.14" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/58d52743ae85d28c9335c6034d6ce350b8689951" }, { "url": "https://git.kernel.org/stable/c/7cd361d5e6d986c0d4cafb9ceaa803359048ae15" }, { "url": "https://git.kernel.org/stable/c/592e57591826f3d09c28d755a39ea8e9d13705ad" }, { "url": "https://git.kernel.org/stable/c/2cfadb761d3d0219412fd8150faea60c7e863833" } ], "title": "netfilter: conntrack: revisit gc autotuning", "x_generator": { "engine": "bippy-1.2.0" } } } }