{"id":"CVE-2026-68117","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-68117","summary":"tipc: clear sock->sk on the failed-insert path in tipc_sk_create()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: clear sock->sk on the failed-insert path in tipc_sk_create()\n\nWhen tipc_sk_create() fails to insert the new socket (tipc_sk_insert()\nreturns non-zero), its error path frees the sk with sk_free() but leaves\nsock->sk pointing at the freed object:\n\n\tif (tipc_sk_insert(tsk)) {\n\t\tsk_free(sk);\n\t\tpr_warn(\"Socket create failed; port number exhausted\\n\");\n\t\treturn -EINVAL;\n\t}\n\nThis is harmless for plain socket(): the syscall layer clears sock->ops\nbefore releasing, so tipc_release() is never called. It is not harmless\non the accept() path. tipc_accept() creates the pre-allocated child\nsocket with tipc_sk_create(net, new_sock, 0, kern); on failure it leaves\nnew_sock->sk dangling and new_sock->ops non-NULL, and do_accept() then\nfput()s the new file, so __sock_release() -> tipc_release() runs\nlock_sock(new_sock->sk) on the freed sk -- a use-after-free write of the\nsk_lock spinlock.\n\ntipc_release() already guards this exact \"failed accept() releases a\npre-allocated child\" case with \"if (sk == NULL) return 0;\", but the\nguard is bypassed because tipc_sk_create() left sock->sk non-NULL\n(dangling) rather than NULL.\n\nClear sock->sk on the failed-insert path so the existing tipc_release()\nNULL check fires and the use-after-free is avoided.\n\nThe tipc_sk_insert() failure is reached when the per-netns socket\nrhashtable hits its max_size (tsk_rht_params.max_size = 1048576, ~2M\nelements) -- i.e. once a netns holds ~2M TIPC sockets every insert\nreturns -E2BIG.\n\n  BUG: KASAN: slab-use-after-free in lock_sock_nested (net/core/sock.c:3839)\n  Write of size 8 at addr ffff8880047cdc38 by task init/1\n   lock_sock_nested (net/core/sock.c:3839)\n   tipc_release (net/tipc/socket.c:638)\n   __sock_release (net/socket.c:710)\n   sock_close (net/socket.c:1501)\n   __fput (fs/file_table.c:512)\n  Allocated by task 1:\n   sk_alloc (net/core/sock.c:2308)\n   tipc_sk_create (net/tipc/socket.c:487)\n   tipc_accept (net/tipc/socket.c:2744)\n   do_accept (net/socket.c:2034)\n  Freed by task 1:\n   __sk_destruct (net/core/sock.c:2391)\n   tipc_sk_create (net/tipc/socket.c:504)\n   tipc_accept (net/tipc/socket.c:2744)\n   do_accept (net/socket.c:2034)","published":"2026-08-10T11:58:36.675Z","modified":"2026-08-14T04:03:55.243426157Z","cvss":{"score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"6.6.148"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/5f5a41a48dbf9eda57b67ce23e548602cf7195a6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b07d87b31631edb6529e6cdcca790a7489d1250d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ba0533fc163f905fe817cfabdf8ed4058da44800"},{"type":"WEB","url":"https://git.kernel.org/stable/c/dd29891ed840f6b8d020b759d0dc4a00b1d6e4ea"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f9596b1566616a8be0592dbceccb6344a7c6f6bb"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68117.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-68117"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-14T04:03:55.243426157Z"}}