CVE-2026-64352: Software Security Vulnerability Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-p2wc-grc5-cwhm",
  "modified" : "2026-09-03T18:31:17Z",
  "published" : "2026-07-25T12:31:32Z",
  "aliases" : [ "CVE-2026-64352" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Allow LPM map access from sleepable BPF programs\n\ntrie_lookup_elem() annotates its rcu_dereference_check() walks with\nonly rcu_read_lock_bh_held().  Because rcu_dereference_check(p, c)\nresolves to \"c || rcu_read_lock_held()\", this passes for XDP/NAPI and\nclassic RCU readers but fails for sleepable BPF programs, which enter\nvia __bpf_prog_enter_sleepable() and hold only rcu_read_lock_trace().\n\ntrie_update_elem() and trie_delete_elem() have the same problem in a\ndifferent form: they walk the trie with plain rcu_dereference(), which\nasserts rcu_read_lock_held() unconditionally.  Both are reachable from\nsleepable BPF programs via the bpf_map_update_elem / bpf_map_delete_elem\nhelpers, and from the syscall path under classic rcu_read_lock().  In\nthe writer paths the trie is actually protected by trie->lock (an\nrqspinlock taken across the walk); we never relied on the RCU read-side\nlock to keep nodes alive there.\n\nA sleepable LSM hook that ends up touching an LPM trie therefore\ntriggers lockdep on debug kernels:\n\n  =============================\n  WARNING: suspicious RCU usage\n  7.1.0-... Tainted: G            E\n  -----------------------------\n  kernel/bpf/lpm_trie.c:249 suspicious rcu_dereference_check() usage!\n  1 lock held by net_tests/540:\n   #0: (rcu_tasks_trace_srcu_struct){....}-{0:0},\n       at: __bpf_prog_enter_sleepable+0x26/0x280\n  Call Trace:\n   dump_stack_lvl\n   lockdep_rcu_suspicious\n   trie_lookup_elem\n   bpf_prog_..._enforce_security_socket_connect\n   bpf_trampoline_...\n   security_socket_connect\n   __sys_connect\n   do_syscall_64\n\nThis is lockdep-only -- no UAF, since Tasks Trace RCU does serialize\nagainst the trie's reclaim path -- but it spams the console once per\ndistinct callsite on every debug kernel running a sleepable BPF LSM\nthat touches an LPM trie, which is increasingly common.\n\nFor the lookup path, switch the rcu_dereference_check() annotation\nfrom rcu_read_lock_bh_held() to bpf_rcu_lock_held(), which accepts all\nthree contexts (classic, BH, Tasks Trace).  Other map types already\nfollow this convention.\n\nFor trie_update_elem() and trie_delete_elem(), annotate the walks as\nrcu_dereference_protected(*p, 1) -- matching trie_free() in the same\nfile -- since trie->lock is held across the walk.  rqspinlock has no\nlockdep_map, so the predicate degenerates to '1' rather than\nlockdep_is_held(&trie->lock); the protection is real but not\nmachine-verifiable.  trie_get_next_key() also uses bare\nrcu_dereference() but is reachable only from the BPF syscall, which\nholds classic rcu_read_lock() before dispatching, so it is left\nuntouched.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-64352"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/2f884d371fafea137afea504d49ee4a7c8d7985b"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/304ca50582f0c047370f85e13caec456f78c9fcc"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/57454944737f3ad9a8703aecbbb79713b513a94b"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/9bfdf4b81b0e56d47bc6c46c34a46638be716695"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/bd6ad9a6b30498d845413e863fb95c6fab3babe3"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/ec662a8b2cde01e76b37ccd4b992d0342299e69c"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/f0967d4f1ba4323a3cb7dc8fdba74dd3a8caaf04"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-416" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-07-25T10:17:17Z"
  }
}