{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64218", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.770Z", "datePublished": "2026-07-24T15:23:05.814Z", "dateUpdated": "2026-08-05T12:40:06.269Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:40:06.269Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbatman-adv: bla: fix report_work leak on backbone_gw purge\n\nbatadv_bla_purge_backbone_gw() removes stale backbone gateway entries,\nbut fails to properly handle their associated report_work:\n\n- If report_work is running, the purge must wait for it to finish before\n freeing the backbone_gw, otherwise the worker may access freed memory\n (e.g. bat_priv).\n- If report_work is pending, the purge must cancel it and release the\n reference held for that pending work item.\n\nThe previous implementation called hlist_for_each_entry_safe() inside a\nspin_lock_bh() section, but cancel_work_sync() may sleep and therefore\ncannot be called from within a spinlock-protected region.\n\nRestructure the loop to handle one entry per spinlock critical section:\nacquire the lock, find the next entry to purge, remove it from the hash\nlist, then release the lock before calling cancel_work_sync() and\ndropping the hash_entry reference. Repeat until no more entries require\npurging." } ], "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 - Although mesh packets can enqueue report_work, exploitation requires purging or tearing down the mesh object, which a local attacker can perform through netlink in a controlled network namespace.\nAC:L - The attacker can observe the periodic loop-detect address, enqueue many VLAN-specific work items, and immediately delete the interface, controlling both sides of the race.\nPR:L - Mesh configuration and teardown require CAP_NET_ADMIN, but batman-adv supports network namespaces and GENL_UNS_ADMIN_PERM, making the path reachable by an otherwise unprivileged user through user namespaces.\nUI:N - The attacker can create, trigger, and tear down the affected mesh interface without action from another user.\nS:U - Exploitation compromises the host kernel within its existing security authority; this is standard kernel privilege escalation rather than a VM or hardware-boundary escape.\nC:H - The worker can dereference a freed bat_priv, net_device, and embedded kobject; controlled reallocation can turn these stale pointer chains into kernel-memory disclosure primitives.\nI:H - The use-after-free reaches kobject uevent processing and stale callback-bearing structures, making heap reuse and control-flow hijacking or arbitrary kernel modification plausible.\nA:H - The stale net_device and kobject dereferences can cause a kernel oops or panic, and an attacker can repeat the trigger through user-namespace-created mesh interfaces." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/batman-adv/bridge_loop_avoidance.c" ], "versions": [ { "version": "23721387c409087fd3b97e274f34d3ddc0970b74", "lessThan": "ce2c0ee4d76d5ee4b391fe0e31334361e25030ec", "status": "affected", "versionType": "git" }, { "version": "23721387c409087fd3b97e274f34d3ddc0970b74", "lessThan": "3423a45e5c3d3c5129f88143a9a969787d7d5a0a", "status": "affected", "versionType": "git" }, { "version": "23721387c409087fd3b97e274f34d3ddc0970b74", "lessThan": "f1303adb1e59582f76c22798a2e2e150e054a9e7", "status": "affected", "versionType": "git" }, { "version": "23721387c409087fd3b97e274f34d3ddc0970b74", "lessThan": "48663158222b3b7f6ee6791a67d512ede7fc94bb", "status": "affected", "versionType": "git" }, { "version": "23721387c409087fd3b97e274f34d3ddc0970b74", "lessThan": "eeddd7bab3d59c1e98642a204141f8c5d6194707", "status": "affected", "versionType": "git" }, { "version": "23721387c409087fd3b97e274f34d3ddc0970b74", "lessThan": "c6de1a5a9c406e30b91f1515a6ce05cc84023baa", "status": "affected", "versionType": "git" }, { "version": "23721387c409087fd3b97e274f34d3ddc0970b74", "lessThan": "95a7034661274cf5985708bd2f6d86ee46f88fa9", "status": "affected", "versionType": "git" }, { "version": "23721387c409087fd3b97e274f34d3ddc0970b74", "lessThan": "0459430add32ea41f3e2ef9351610e6d33627a6b", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/batman-adv/bridge_loop_avoidance.c" ], "versions": [ { "version": "3.5", "status": "affected" }, { "version": "0", "lessThan": "3.5", "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": "6.6.142", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.92", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.34", "lessThanOrEqual": "6.18.*", "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": "3.5", "versionEndExcluding": "5.10.258" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "5.15.209" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "6.1.175" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "6.6.142" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "6.12.92" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "6.18.34" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "7.0.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/ce2c0ee4d76d5ee4b391fe0e31334361e25030ec" }, { "url": "https://git.kernel.org/stable/c/3423a45e5c3d3c5129f88143a9a969787d7d5a0a" }, { "url": "https://git.kernel.org/stable/c/f1303adb1e59582f76c22798a2e2e150e054a9e7" }, { "url": "https://git.kernel.org/stable/c/48663158222b3b7f6ee6791a67d512ede7fc94bb" }, { "url": "https://git.kernel.org/stable/c/eeddd7bab3d59c1e98642a204141f8c5d6194707" }, { "url": "https://git.kernel.org/stable/c/c6de1a5a9c406e30b91f1515a6ce05cc84023baa" }, { "url": "https://git.kernel.org/stable/c/95a7034661274cf5985708bd2f6d86ee46f88fa9" }, { "url": "https://git.kernel.org/stable/c/0459430add32ea41f3e2ef9351610e6d33627a6b" } ], "title": "batman-adv: bla: fix report_work leak on backbone_gw purge", "x_generator": { "engine": "bippy-1.2.0" } } } }