{"cve":"CVE-2025-38154","nvd":{"published":"2025-07-03T09:15:30.363","modified":"2026-10-15T22:18:29.153","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf, sockmap: Avoid using sk_socket after free when sending\n\nThe sk->sk_socket is not locked or referenced in backlog thread, and\nduring the call to skb_send_sock(), there is a race condition with\nthe release of sk_socket. All types of sockets(tcp/udp/unix/vsock)\nwill be affected.\n\nRace conditions:\n'''\nCPU0                               CPU1\n\nbacklog::skb_send_sock\n  sendmsg_unlocked\n    sock_sendmsg\n      sock_sendmsg_nosec\n                                   close(fd):\n                                     ...\n                                     ops->release() -> sock_map_close()\n                                     sk_socket->ops = NULL\n                                     free(socket)\n      sock->ops->sendmsg\n            ^\n            panic here\n'''\n\nThe ref of psock become 0 after sock_map_close() executed.\n'''\nvoid sock_map_close()\n{\n    ...\n    if (likely(psock)) {\n    ...\n    // !! here we remove psock and the ref of psock become 0\n    sock_map_remove_links(sk, psock)\n    psock = sk_psock_get(sk);\n    if (unlikely(!psock))\n        goto no_psock; <=== Control jumps here via goto\n        ...\n        cancel_delayed_work_sync(&psock->work); <=== not executed\n        sk_psock_put(sk, psock);\n        ...\n}\n'''\n\nBased on the fact that we already wait for the workqueue to finish in\nsock_map_close() if psock is held, we simply increase the psock\nreference count to avoid race conditions.\n\nWith this patch, if the backlog thread is running, sock_map_close() will\nwait for the backlog thread to complete and cancel all pending work.\n\nIf no backlog running, any pending work that hasn't started by then will\nfail when invoked by sk_psock_get(), as the psock reference count have\nbeen zeroed, and sk_psock_drop() will cancel all jobs via\ncancel_delayed_work_sync().\n\nIn summary, we require synchronization to coordinate the backlog thread\nand close() thread.\n\nThe panic I catched:\n'''\nWorkqueue: events sk_psock_backlog\nRIP: 0010:sock_sendmsg+0x21d/0x440\nRAX: 0000000000000000 RBX: ffffc9000521fad8 RCX: 0000000000000001\n...\nCall Trace:\n <TASK>\n ? die_addr+0x40/0xa0\n ? exc_general_protection+0x14c/0x230\n ? asm_exc_general_protection+0x26/0x30\n ? sock_sendmsg+0x21d/0x440\n ? sock_sendmsg+0x3e0/0x440\n ? __pfx_sock_sendmsg+0x10/0x10\n __skb_send_sock+0x543/0xb70\n sk_psock_backlog+0x247/0xb80\n...\n'''","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-416"],"references":["https://git.kernel.org/stable/c/15c0250dae3b48a398447d2b364603821ed4ed90","https://git.kernel.org/stable/c/4c6fa65ab2aec7df94809478c8d28ef38676a1b7","https://git.kernel.org/stable/c/4edb40b05cb6a261775abfd8046804ca139a5546","https://git.kernel.org/stable/c/7c0a16f6ea2b1c82a03bccd5d1bdb4a7bbd4d987","https://git.kernel.org/stable/c/8259eb0e06d8f64c700f5fbdb28a5c18e10de291"],"products":["debian:debian_linux","linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:04:28.436527499+00:00"},"epss":{"cve":"CVE-2025-38154","score":0.00186,"percentile":0.08157,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}