{"id":"CVE-2026-64352","title":"bpf: Allow LPM map access from sleepable BPF programs","summary":"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_de…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 694cea395fded425008e93cd90cfdf7a451674af < f0967d4f1ba4323a3cb7dc8fdba74dd3a8caaf04","Linux >= 694cea395fded425008e93cd90cfdf7a451674af < 304ca50582f0c047370f85e13caec456f78c9fcc","Linux >= 694cea395fded425008e93cd90cfdf7a451674af < ec662a8b2cde01e76b37ccd4b992d0342299e69c","Linux >= 694cea395fded425008e93cd90cfdf7a451674af < 9bfdf4b81b0e56d47bc6c46c34a46638be716695","Linux >= 694cea395fded425008e93cd90cfdf7a451674af < 57454944737f3ad9a8703aecbbb79713b513a94b","Linux >= 694cea395fded425008e93cd90cfdf7a451674af < bd6ad9a6b30498d845413e863fb95c6fab3babe3","Linux >= 694cea395fded425008e93cd90cfdf7a451674af < 2f884d371fafea137afea504d49ee4a7c8d7985b","Linux 5.14"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-06T16:36:44.456089Z"},"published":"2026-07-25","updated":"2026-11-06","sourceUpdated":"2026-11-06T16:44:48.606Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-64352","references":[{"url":"https://git.kernel.org/stable/c/f0967d4f1ba4323a3cb7dc8fdba74dd3a8caaf04"},{"url":"https://git.kernel.org/stable/c/304ca50582f0c047370f85e13caec456f78c9fcc"},{"url":"https://git.kernel.org/stable/c/ec662a8b2cde01e76b37ccd4b992d0342299e69c"},{"url":"https://git.kernel.org/stable/c/9bfdf4b81b0e56d47bc6c46c34a46638be716695"},{"url":"https://git.kernel.org/stable/c/57454944737f3ad9a8703aecbbb79713b513a94b"},{"url":"https://git.kernel.org/stable/c/bd6ad9a6b30498d845413e863fb95c6fab3babe3"},{"url":"https://git.kernel.org/stable/c/2f884d371fafea137afea504d49ee4a7c8d7985b"}],"tags":["cve.org"],"epss":0.00129,"epssPercentile":0.02574,"ingestedAt":"2026-11-06T16:57:43.191Z","slug":"CVE-2026-64352","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `Linux >= 694cea395fded425008e93cd90cfdf7a451674af < f0967d4f1ba4323a3cb7dc8fdba74dd3a8caaf04`\n- `Linux >= 694cea395fded425008e93cd90cfdf7a451674af < 304ca50582f0c047370f85e13caec456f78c9fcc`\n- `Linux >= 694cea395fded425008e93cd90cfdf7a451674af < ec662a8b2cde01e76b37ccd4b992d0342299e69c`\n- `Linux >= 694cea395fded425008e93cd90cfdf7a451674af < 9bfdf4b81b0e56d47bc6c46c34a46638be716695`\n- `Linux >= 694cea395fded425008e93cd90cfdf7a451674af < 57454944737f3ad9a8703aecbbb79713b513a94b`\n- `Linux >= 694cea395fded425008e93cd90cfdf7a451674af < bd6ad9a6b30498d845413e863fb95c6fab3babe3`\n- `Linux >= 694cea395fded425008e93cd90cfdf7a451674af < 2f884d371fafea137afea504d49ee4a7c8d7985b`\n- `Linux 5.14`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}