{"id":"CVE-2026-64575","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-64575","summary":"bpf: tcp: fix double sock release on batch realloc","details":"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","published":"2026-08-05T08:09:31.923Z","modified":"2026-08-09T03:47:25.604055064Z","cvss":{"score":7.8,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"6.18.42"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/8a726e9585ffe7bfbfad2b5279277a00973970f3"},{"type":"WEB","url":"https://git.kernel.org/stable/c/980a813452754f8001704744e92f7aa697c53dd3"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9f27c4f0ae35b5390ce4f7a54d3501144e41a54d"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64575.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64575"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-09T03:47:25.604055064Z"}}