{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64123", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T07:54:57.036Z", "datePublished": "2026-07-19T15:40:21.161Z", "dateUpdated": "2026-08-05T12:39:29.748Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:39:29.748Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: hsr: defer node table free until after RCU readers\n\nHSR node-list and node-status generic-netlink operations run under\nrcu_read_lock(). They walk hsr->node_db through hsr_get_next_node() and\nhsr_get_node_data(), but RTM_DELLINK teardown removes the same node table\nwith plain list_del() and frees each node immediately.\n\nThat lets a generic-netlink reader hold a struct hsr_node pointer across\nhsr_dellink(). In a KASAN build, widening the reader window after\nhsr_get_next_node() obtains the node reproduces a slab-use-after-free\nwhen the reader copies node->macaddress_A; the freeing stack is\nhsr_del_nodes() from hsr_dellink().\n\nUse list_del_rcu() and defer the free through the existing\nhsr_free_node_rcu() callback. This matches the lifetime rule used by the\nHSR prune paths, which already delete nodes with list_del_rcu() and\ncall_rcu()." } ], "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 - Exploitation requires local netlink access: generic-netlink HSR_C_GET_NODE_LIST/HSR_C_GET_NODE_STATUS and rtnetlink RTM_DELLINK. The bug is not reachable via HSR/PRP network frames despite HSR being a network redundancy protocol.\nAC:L - The attacker controls both sides of the race by issuing concurrent GENL node queries and RTM_DELLINK on separate threads; no unpredictable victim state or memory layout is required beyond having an HSR interface configured.\nPR:L - Reliable exploitation requires CAP_NET_ADMIN to delete the HSR device via RTM_DELLINK (and typically to create it); CAP_NET_ADMIN is obtainable by an unprivileged user through user namespaces (unshare -Urn), and the GENL read operations themselves carry no admin-perm flag.\nUI:N - No victim interaction is required; the race is triggered entirely by the attacker's own concurrent netlink operations.\nS:U - Impact is confined to kernel memory corruption and privilege escalation within the same kernel/host security boundary, not a cross-boundary escape such as VM or sandbox breakout.\nC:H - This is a slab use-after-free on struct hsr_node; freed objects can be reallocated and read through fields like macaddress_A/B and block_buf, enabling arbitrary kernel memory disclosure.\nI:H - UAF on a kmalloc'd hsr_node with spinlock and pointer fields (block_buf, seq_blocks) provides standard heap-spray primitives for arbitrary kernel writes and potential code execution.\nA:H - Use-after-free on hsr_node during RCU-protected traversal causes kernel oops/panic even without full exploitation, as confirmed by KASAN on the macaddress_A copy path." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/hsr/hsr_framereg.c" ], "versions": [ { "version": "b9a1e627405d68d475a3c1f35e685ccfb5bbe668", "lessThan": "0ea70fb46940620848c08d9d399455c9e82fecdb", "status": "affected", "versionType": "git" }, { "version": "b9a1e627405d68d475a3c1f35e685ccfb5bbe668", "lessThan": "8be6685cdd1255bcc85f9b59e4bfc313aefc5c1b", "status": "affected", "versionType": "git" }, { "version": "b9a1e627405d68d475a3c1f35e685ccfb5bbe668", "lessThan": "c5580114e0492bcd2e0a37613ed4c311e3fa3d4d", "status": "affected", "versionType": "git" }, { "version": "b9a1e627405d68d475a3c1f35e685ccfb5bbe668", "lessThan": "7713f4aafb577ff49fa67f0488d9c7dddc64d6ce", "status": "affected", "versionType": "git" }, { "version": "b9a1e627405d68d475a3c1f35e685ccfb5bbe668", "lessThan": "6324423a8e6591f41a16c09a8f9a84e554ac147c", "status": "affected", "versionType": "git" }, { "version": "b9a1e627405d68d475a3c1f35e685ccfb5bbe668", "lessThan": "8c3af18bb0d7c921a5219194037509463eb2ffde", "status": "affected", "versionType": "git" }, { "version": "b9a1e627405d68d475a3c1f35e685ccfb5bbe668", "lessThan": "aaec7096f9961eb223b5b149abe9495525c205d9", "status": "affected", "versionType": "git" }, { "version": "08523d5a2f4a9e4202e00d282c164d453cabe2d2", "status": "affected", "versionType": "git" }, { "version": "5.2.12", "lessThan": "5.3", "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/hsr/hsr_framereg.c" ], "versions": [ { "version": "5.3", "status": "affected" }, { "version": "0", "lessThan": "5.3", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.259", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.210", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.176", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.143", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.93", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.11", "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": "5.3", "versionEndExcluding": "5.10.259" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.3", "versionEndExcluding": "5.15.210" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.3", "versionEndExcluding": "6.1.176" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.3", "versionEndExcluding": "6.6.143" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.3", "versionEndExcluding": "6.12.93" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.3", "versionEndExcluding": "7.0.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.3", "versionEndExcluding": "7.1" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2.12" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/0ea70fb46940620848c08d9d399455c9e82fecdb" }, { "url": "https://git.kernel.org/stable/c/8be6685cdd1255bcc85f9b59e4bfc313aefc5c1b" }, { "url": "https://git.kernel.org/stable/c/c5580114e0492bcd2e0a37613ed4c311e3fa3d4d" }, { "url": "https://git.kernel.org/stable/c/7713f4aafb577ff49fa67f0488d9c7dddc64d6ce" }, { "url": "https://git.kernel.org/stable/c/6324423a8e6591f41a16c09a8f9a84e554ac147c" }, { "url": "https://git.kernel.org/stable/c/8c3af18bb0d7c921a5219194037509463eb2ffde" }, { "url": "https://git.kernel.org/stable/c/aaec7096f9961eb223b5b149abe9495525c205d9" } ], "title": "net: hsr: defer node table free until after RCU readers", "x_generator": { "engine": "bippy-1.2.0" } } } }