{"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"}}}}