{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64575", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.797Z", "datePublished": "2026-08-05T08:09:31.923Z", "dateUpdated": "2026-08-19T16:28:54.764Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-19T16:28:54.764Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: tcp: fix double sock release on batch realloc\n\nbpf_iter_tcp_batch() releases the current batch via\nbpf_iter_tcp_put_batch(), which drops the socket refs and rewrites\neach slot with the socket cookie, then grows the batch. cur_sk/end_sk\nare kept for bpf_iter_tcp_resume(), but on realloc failure the function\nreturns ERR_PTR() before resume runs, leaving cur_sk < end_sk over\nslots that now hold cookies rather than sock pointers.\nbpf_iter_tcp_seq_stop() then calls bpf_iter_tcp_put_batch() again and\ndereferences a cookie as a struct sock.\n\nEmpty the batch on the failure path so stop() does not release it\nagain. The sockets were already freed by the first\nbpf_iter_tcp_put_batch(), so nothing leaks, and a later read() rescans\nthe bucket from the start instead of skipping it. The sibling\nGFP_NOWAIT failure path still holds real socket references and is left\nfor stop() to release.\n\n BUG: KASAN: null-ptr-deref in __sock_gen_cookie\n Read of size 8 at addr 0000000000000059 by task exploit\n ...\n __sock_gen_cookie (net/core/sock_diag.c:28)\n bpf_iter_tcp_put_batch (net/ipv4/tcp_ipv4.c:2918)\n bpf_iter_tcp_seq_stop (net/ipv4/tcp_ipv4.c:3270)\n bpf_seq_read (kernel/bpf/bpf_iter.c:205)\n vfs_read (fs/read_write.c:572)\n ksys_read (fs/read_write.c:716)\n do_syscall_64\n entry_SYSCALL_64_after_hwframe\n Kernel panic - not syncing: Fatal exception" } ], "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 - Reached only through local bpf() syscalls that load a BPF_TRACE_ITER TCP program, create an iterator fd, and read it; bpf_seq_read drives bpf_iter_tcp_batch/stop. Per guidance BPF subsystem bugs are Local, not network-reachable.\nAC:L - The attacker controls both prerequisites: creating more than INIT_BATCH_SZ TCP sockets in one hash bucket to force bpf_iter_tcp_put_batch-then-realloc, and inducing GFP_USER -ENOMEM (memory pressure/cgroup limits) so the failure path runs without races outside their control.\nPR:L - Loading BPF_PROG_TYPE_TRACING/BPF_TRACE_ITER requires CAP_BPF and CAP_PERFMON, which BPF tokens can delegate into a non-init user namespace; consistent with other BPF iterator CVEs this is Low rather than full init-namespace root.\nUI:N - The attacker loads their own TCP iterator program and triggers the bug by reading their iterator fd; no victim action such as mounting, opening a file, or interacting with the attacker is required.\nS:U - Impact is kernel memory corruption and panic within the same host kernel security authority; this is a standard local kernel bug, not a VM/hypervisor escape or IOMMU boundary bypass.\nC:H - stop() re-enters bpf_iter_tcp_put_batch and treats stored socket cookies as struct sock pointers, so sock_gen_cookie performs an out-of-bounds/wild kernel read; type-confused pointer dereference supports high confidentiality impact under the higher-severity rule.\nI:H - The same type confusion reaches sock_gen_put, which decrements sk_refcnt and may free through the forged pointer, yielding kernel memory corruption and a plausible control-flow/integrity primitive beyond a clean crash.\nA:H - The reported path is a KASAN null-ptr-deref in __sock_gen_cookie during bpf_iter_tcp_seq_stop that ends in kernel panic; the attacker can repeat the iterator read to deny host availability." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ipv4/tcp_ipv4.c" ], "versions": [ { "version": "9794ac757a650dd594391192183c9caf939f8223", "lessThan": "c842882e4c5d2818b858d6baf3fd10958c93f729", "status": "affected", "versionType": "git" }, { "version": "1d7a82c1df5fc397eaca9c6b8c8f61aae9866ad4", "lessThan": "7a6a6d2a127866935f87b55b557bc89693065462", "status": "affected", "versionType": "git" }, { "version": "36f955807ee4ede07e9410772f792e4cb4ec807b", "lessThan": "f0c1810320b0dac228103fad7311e89532134d83", "status": "affected", "versionType": "git" }, { "version": "cdec67a489d4fdae3e83e04fca0419136a83c4c2", "lessThan": "9f27c4f0ae35b5390ce4f7a54d3501144e41a54d", "status": "affected", "versionType": "git" }, { "version": "cdec67a489d4fdae3e83e04fca0419136a83c4c2", "lessThan": "8a726e9585ffe7bfbfad2b5279277a00973970f3", "status": "affected", "versionType": "git" }, { "version": "cdec67a489d4fdae3e83e04fca0419136a83c4c2", "lessThan": "980a813452754f8001704744e92f7aa697c53dd3", "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/ipv4/tcp_ipv4.c" ], "versions": [ { "version": "6.17", "status": "affected" }, { "version": "0", "lessThan": "6.17", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.42", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.6", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "6.17", "versionEndExcluding": "6.18.42" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.17", "versionEndExcluding": "7.1.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.17", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/c842882e4c5d2818b858d6baf3fd10958c93f729" }, { "url": "https://git.kernel.org/stable/c/7a6a6d2a127866935f87b55b557bc89693065462" }, { "url": "https://git.kernel.org/stable/c/f0c1810320b0dac228103fad7311e89532134d83" }, { "url": "https://git.kernel.org/stable/c/9f27c4f0ae35b5390ce4f7a54d3501144e41a54d" }, { "url": "https://git.kernel.org/stable/c/8a726e9585ffe7bfbfad2b5279277a00973970f3" }, { "url": "https://git.kernel.org/stable/c/980a813452754f8001704744e92f7aa697c53dd3" } ], "title": "bpf: tcp: fix double sock release on batch realloc", "x_generator": { "engine": "bippy-1.2.0" } } } }