{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-38614", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:24.029Z", "datePublished": "2025-08-19T17:03:56.348Z", "dateUpdated": "2026-08-05T12:03:29.308Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:03:29.308Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\neventpoll: Fix semi-unbounded recursion\n\nEnsure that epoll instances can never form a graph deeper than\nEP_MAX_NESTS+1 links.\n\nCurrently, ep_loop_check_proc() ensures that the graph is loop-free and\ndoes some recursion depth checks, but those recursion depth checks don't\nlimit the depth of the resulting tree for two reasons:\n\n - They don't look upwards in the tree.\n - If there are multiple downwards paths of different lengths, only one of\n the paths is actually considered for the depth check since commit\n 28d82dc1c4ed (\"epoll: limit paths\").\n\nEssentially, the current recursion depth check in ep_loop_check_proc() just\nserves to prevent it from recursing too deeply while checking for loops.\n\nA more thorough check is done in reverse_path_check() after the new graph\nedge has already been created; this checks, among other things, that no\npaths going upwards from any non-epoll file with a length of more than 5\nedges exist. However, this check does not apply to non-epoll files.\n\nAs a result, it is possible to recurse to a depth of at least roughly 500,\ntested on v6.15. (I am unsure if deeper recursion is possible; and this may\nhave changed with commit 8c44dac8add7 (\"eventpoll: Fix priority inversion\nproblem\").)\n\nTo fix it:\n\n1. In ep_loop_check_proc(), note the subtree depth of each visited node,\nand use subtree depths for the total depth calculation even when a subtree\nhas already been visited.\n2. Add ep_get_upwards_depth_proc() for similarly determining the maximum\ndepth of an upwards walk.\n3. In ep_loop_check(), use these values to limit the total path length\nbetween epoll nodes to EP_MAX_NESTS edges." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerability is reached exclusively through the local epoll syscall interface (epoll_create/epoll_ctl/epoll_wait); there is no network-reachable path to build or trigger the nested epoll graph.\nAC:L - The attacker fully controls construction of the deep epoll chain via EPOLL_CTL_ADD and deterministically triggers the recursive walk; no race or uncontrolled condition is involved.\nPR:L - Any unprivileged local user can create and nest epoll instances and invoke poll/epoll_wait — no capabilities, root, or namespaces are required.\nUI:N - The attacker performs every step (nesting the fds and triggering the recursion) alone; no victim action is needed.\nS:U - The stack overflow corrupts kernel memory within the same security authority (the kernel); it does not cross a VM/IOMMU/sandbox boundary.\nC:H - On configs without VMAP_STACK guard pages (32-bit ARM, embedded, older kernels in the affected range), the recursion overflows the kernel stack into adjacent kernel memory, a corruption that can be leveraged to disclose kernel memory.\nI:H - The kernel-stack overflow overwrites adjacent kernel structures (historically thread_info/addr_limit), providing a memory-corruption primitive that can be steered toward control-flow hijack and arbitrary write.\nA:H - The semi-unbounded recursion reliably exhausts the 8–16KB kernel stack, causing a guard-page panic or oops and taking down the entire system." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/eventpoll.c" ], "versions": [ { "version": "22bacca48a1755f79b7e0f192ddb9fbb7fc6e64e", "lessThan": "71379495ab70eaba19224bd71b5b9b399eb85e04", "status": "affected", "versionType": "git" }, { "version": "22bacca48a1755f79b7e0f192ddb9fbb7fc6e64e", "lessThan": "1b13b033062824495554e836a1ff5f85ccf6b039", "status": "affected", "versionType": "git" }, { "version": "22bacca48a1755f79b7e0f192ddb9fbb7fc6e64e", "lessThan": "2a0c0c974bea9619c6f41794775ae4b97530e0e6", "status": "affected", "versionType": "git" }, { "version": "22bacca48a1755f79b7e0f192ddb9fbb7fc6e64e", "lessThan": "7a2125962c42d5336ca0495a9ce4cb38a63e9161", "status": "affected", "versionType": "git" }, { "version": "22bacca48a1755f79b7e0f192ddb9fbb7fc6e64e", "lessThan": "ea5f97dbdcb1651581a22bd10afd2f0dd9dc11d6", "status": "affected", "versionType": "git" }, { "version": "22bacca48a1755f79b7e0f192ddb9fbb7fc6e64e", "lessThan": "3542c90797bc3ab83ebab54b737d751cf3682036", "status": "affected", "versionType": "git" }, { "version": "22bacca48a1755f79b7e0f192ddb9fbb7fc6e64e", "lessThan": "f2e467a48287c868818085aa35389a224d226732", "status": "affected", "versionType": "git" }, { "version": "8216e1a0d47cae06a75c42346f19dffe14e42d57", "status": "affected", "versionType": "git" }, { "version": "28a92748aa4bc57d35e7b079498b0ac2e7610a37", "status": "affected", "versionType": "git" }, { "version": "7eebcd4792c5a341559aed327b6afecbb1c46402", "status": "affected", "versionType": "git" }, { "version": "0eccd188cfeaf857a26f2d72941d27d298cf6a54", "status": "affected", "versionType": "git" }, { "version": "a72affdbb09f3f24f64ffcbbdf62c2e57c58f379", "status": "affected", "versionType": "git" }, { "version": "2.6.32.30", "lessThan": "2.6.33", "status": "affected", "versionType": "semver" }, { "version": "2.6.33.8", "lessThan": "2.6.34", "status": "affected", "versionType": "semver" }, { "version": "2.6.34.10", "lessThan": "2.6.35", "status": "affected", "versionType": "semver" }, { "version": "2.6.35.12", "lessThan": "2.6.36", "status": "affected", "versionType": "semver" }, { "version": "2.6.37.3", "lessThan": "2.6.38", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/eventpoll.c" ], "versions": [ { "version": "2.6.38", "status": "affected" }, { "version": "0", "lessThan": "2.6.38", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.190", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.149", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.103", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.43", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.15.11", "lessThanOrEqual": "6.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.16.1", "lessThanOrEqual": "6.16.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.17", "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": "2.6.38", "versionEndExcluding": "5.15.190" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "6.1.149" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "6.6.103" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "6.12.43" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "6.15.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "6.16.1" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "6.17" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.32.30" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.33.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.34.10" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.35.12" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/71379495ab70eaba19224bd71b5b9b399eb85e04" }, { "url": "https://git.kernel.org/stable/c/1b13b033062824495554e836a1ff5f85ccf6b039" }, { "url": "https://git.kernel.org/stable/c/2a0c0c974bea9619c6f41794775ae4b97530e0e6" }, { "url": "https://git.kernel.org/stable/c/7a2125962c42d5336ca0495a9ce4cb38a63e9161" }, { "url": "https://git.kernel.org/stable/c/ea5f97dbdcb1651581a22bd10afd2f0dd9dc11d6" }, { "url": "https://git.kernel.org/stable/c/3542c90797bc3ab83ebab54b737d751cf3682036" }, { "url": "https://git.kernel.org/stable/c/f2e467a48287c868818085aa35389a224d226732" } ], "title": "eventpoll: Fix semi-unbounded recursion", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T17:40:26.593Z" } }, { "x_adpType": 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