{"id":"CVE-2022-50555","summary":"tipc: fix a null-ptr-deref in tipc_topsrv_accept","details":"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   \u003cTASK\u003e\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-\u003elistener 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-\u003elistener is protected by srv-\u003eidr_lock in tipc_topsrv_stop(), so add\na check for srv-\u003elistener under srv-\u003eidr_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-\u003esk_user_data instead of\nsrv-\u003elistener, 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-\u003esk_user_data to null.","modified":"2026-04-02T08:28:37.178393Z","published":"2025-10-07T15:21:16.179Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/50xxx/CVE-2022-50555.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/24b129aed8730e48f47d852d58d76825ab6f407c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/32a3d4660b34ce49ac0162338ebe362098e2f5df"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7a939503fc32bff4ed60800b73ff7fbb4aea2142"},{"type":"WEB","url":"https://git.kernel.org/stable/c/82cb4e4612c633a9ce320e1773114875604a3cce"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ce69bdac2310152bb70845024d5d704c52aabfc3"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cedb41664e27b2cae7e21487f1bee22dcd84037d"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/50xxx/CVE-2022-50555.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2022-50555"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"0ef897be12b8b4cf297b6016e79ec97ec90f2cf6"},{"fixed":"ce69bdac2310152bb70845024d5d704c52aabfc3"},{"fixed":"24b129aed8730e48f47d852d58d76825ab6f407c"},{"fixed":"32a3d4660b34ce49ac0162338ebe362098e2f5df"},{"fixed":"7a939503fc32bff4ed60800b73ff7fbb4aea2142"},{"fixed":"cedb41664e27b2cae7e21487f1bee22dcd84037d"},{"fixed":"82cb4e4612c633a9ce320e1773114875604a3cce"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-50555.json"}}],"schema_version":"1.7.5"}