{"cve":"CVE-2022-50555","nvd":{"published":"2025-10-07T16:15:43.850","modified":"2026-08-04T10:18:19.357","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: fix a null-ptr-deref in tipc_topsrv_accept\n\nsyzbot found a crash in tipc_topsrv_accept:\n\n  KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]\n  Workqueue: tipc_rcv tipc_topsrv_accept\n  RIP: 0010:kernel_accept+0x22d/0x350 net/socket.c:3487\n  Call Trace:\n   <TASK>\n   tipc_topsrv_accept+0x197/0x280 net/tipc/topsrv.c:460\n   process_one_work+0x991/0x1610 kernel/workqueue.c:2289\n   worker_thread+0x665/0x1080 kernel/workqueue.c:2436\n   kthread+0x2e4/0x3a0 kernel/kthread.c:376\n   ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306\n\nIt was caused by srv->listener that might be set to null by\ntipc_topsrv_stop() in net .exit whereas it's still used in\ntipc_topsrv_accept() worker.\n\nsrv->listener is protected by srv->idr_lock in tipc_topsrv_stop(), so add\na check for srv->listener under srv->idr_lock in tipc_topsrv_accept() to\navoid the null-ptr-deref. To ensure the lsock is not released during the\ntipc_topsrv_accept(), move sock_release() after tipc_topsrv_work_stop()\nwhere it's waiting until the tipc_topsrv_accept worker to be done.\n\nNote that sk_callback_lock is used to protect sk->sk_user_data instead of\nsrv->listener, and it should check srv in tipc_topsrv_listener_data_ready()\ninstead. This also ensures that no more tipc_topsrv_accept worker will be\nstarted after tipc_conn_close() is called in tipc_topsrv_stop() where it\nsets sk->sk_user_data to null.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-476"],"references":["https://git.kernel.org/stable/c/24b129aed8730e48f47d852d58d76825ab6f407c","https://git.kernel.org/stable/c/32a3d4660b34ce49ac0162338ebe362098e2f5df","https://git.kernel.org/stable/c/7a939503fc32bff4ed60800b73ff7fbb4aea2142","https://git.kernel.org/stable/c/82cb4e4612c633a9ce320e1773114875604a3cce","https://git.kernel.org/stable/c/ce69bdac2310152bb70845024d5d704c52aabfc3"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:11:26.888974865+00:00"},"epss":{"cve":"CVE-2022-50555","score":0.0022,"percentile":0.12534,"date":"2026-10-31"},"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."]}