{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-46120", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-13T15:03:33.098Z", "datePublished": "2026-05-28T09:35:35.385Z", "dateUpdated": "2026-08-05T12:29:51.685Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:29:51.685Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nip6_gre: Use cached t->net in ip6erspan_changelink().\n\nAfter commit 5e72ce3e3980 (\"net: ipv6: Use link netns in newlink() of\nrtnl_link_ops\"), ip6erspan_newlink() correctly resolves the per-netns\nip6gre hash via link_net. ip6erspan_changelink() was not converted in\nthat series and still uses dev_net(dev), which diverges from the\ndevice's creation netns after IFLA_NET_NS_FD migration.\n\nThis re-inserts the tunnel into the wrong per-netns hash. The\noriginal netns keeps a stale entry. When that netns is later\ndestroyed, ip6gre_exit_rtnl_net() walks the stale entry, producing a\nslab-use-after-free reported by KASAN, followed by a kernel BUG at\nnet/core/dev.c (LIST_POISON1) in unregister_netdevice_many_notify().\n\nReachable from an unprivileged user namespace (unshare --user\n--map-root-user --net).\n\nip6gre_changelink() earlier in the same file already uses the cached\nt->net; only ip6erspan_changelink() has the wrong shape." } ], "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 vulnerable code is reached only via local netlink operations (RTM_NEWLINK changelink, IFLA_NET_NS_FD device migration, and netns teardown), not from any remote packet path; this is a local attack surface.\nAC:L - The attacker deterministically performs every step (create erspan tunnel, migrate it to another netns, issue changelink, destroy the original netns) with no race or memory-layout condition outside their control.\nPR:L - The path nominally needs CAP_NET_ADMIN, but the fix commit explicitly states it is reachable from an unprivileged user namespace via `unshare --user --map-root-user --net`, so only a basic local user is required.\nUI:N - The entire sequence is driven by the attacker's own process; no action by any other user is needed.\nS:U - The use-after-free and resulting crash are confined to the kernel's own structures within the same security authority; no boundary such as VM/IOMMU is crossed.\nC:H - The stale hash entry yields a slab-use-after-free on the ip6_tnl/net_device object; reallocating the freed slab with attacker-controlled data enables reading kernel memory contents, treated as High.\nI:H - The use-after-free permits heap grooming and writes through the dangling pointer (e.g., the rcu list manipulation in unregister), providing an arbitrary-write/control-flow primitive, scored High.\nA:H - Exploitation reliably produces a KASAN slab-use-after-free followed by a kernel BUG (LIST_POISON1) in unregister_netdevice_many_notify(), crashing the kernel." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ipv6/ip6_gre.c" ], "versions": [ { "version": "2d665034f239412927b1e71329f20f001c92da09", "lessThan": "7bd0f2b162b426b343a114e1b329f0d8d14fdc6e", "status": "affected", "versionType": "git" }, { "version": "2d665034f239412927b1e71329f20f001c92da09", "lessThan": "01b71ff2857d3598337de11e7840a8e3ff21553c", "status": "affected", "versionType": "git" }, { "version": "2d665034f239412927b1e71329f20f001c92da09", "lessThan": "0fcf6731706f73494245a9c0d64f93bebf95bb51", "status": "affected", "versionType": "git" }, { "version": "2d665034f239412927b1e71329f20f001c92da09", "lessThan": "eca62bb0569de4d43a4dac06a2092a9d4ca1d702", "status": "affected", "versionType": "git" }, { "version": "2d665034f239412927b1e71329f20f001c92da09", "lessThan": "311fdd26eb4443d43b909cc67a10f3a5fd1b21b2", "status": "affected", "versionType": "git" }, { "version": "2d665034f239412927b1e71329f20f001c92da09", "lessThan": "e70cfb40c3a99b232cd42c6a6a10f0d8e039dc82", "status": "affected", "versionType": "git" }, { "version": "2d665034f239412927b1e71329f20f001c92da09", "lessThan": "cf7fc624329e76c6394653d12353e1d033adea91", "status": "affected", "versionType": "git" }, { "version": "2d665034f239412927b1e71329f20f001c92da09", "lessThan": "1d324c2f43f70c965f25c58cc3611c779adbe47e", "status": "affected", "versionType": "git" }, { "version": "c6d72628352c949629af619b77b042e0fb5245e7", "status": "affected", "versionType": "git" }, { "version": "4.16.12", "lessThan": "4.17", "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/ipv6/ip6_gre.c" ], "versions": [ { "version": "4.17", "status": "affected" }, { "version": "0", "lessThan": "4.17", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.258", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.209", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.175", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.140", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.88", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.30", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.7", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "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": "4.17", "versionEndExcluding": "5.10.258" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "5.15.209" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "6.1.175" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "6.6.140" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "6.12.88" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "6.18.30" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "7.0.7" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "7.1" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16.12" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/7bd0f2b162b426b343a114e1b329f0d8d14fdc6e" }, { "url": "https://git.kernel.org/stable/c/01b71ff2857d3598337de11e7840a8e3ff21553c" }, { "url": "https://git.kernel.org/stable/c/0fcf6731706f73494245a9c0d64f93bebf95bb51" }, { "url": "https://git.kernel.org/stable/c/eca62bb0569de4d43a4dac06a2092a9d4ca1d702" }, { "url": "https://git.kernel.org/stable/c/311fdd26eb4443d43b909cc67a10f3a5fd1b21b2" }, { "url": "https://git.kernel.org/stable/c/e70cfb40c3a99b232cd42c6a6a10f0d8e039dc82" }, { "url": "https://git.kernel.org/stable/c/cf7fc624329e76c6394653d12353e1d033adea91" }, { "url": "https://git.kernel.org/stable/c/1d324c2f43f70c965f25c58cc3611c779adbe47e" } ], "title": "ip6_gre: Use cached t->net in ip6erspan_changelink().", "x_generator": { "engine": "bippy-1.2.0" } } } }