{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2022-50555", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-10-07T15:15:38.669Z", "datePublished": "2025-10-07T15:21:16.179Z", "dateUpdated": "2026-08-05T08:59:07.298Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:59:07.298Z" }, "descriptions": [ { "lang": "en", "value": "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 \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." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The topology server is bound with TIPC_NODE_SCOPE and is only reachable via local AF_TIPC sockets on the same node; remote TIPC/UDP peers cannot connect to topsrv.\nAC:L - The attacker controls both sides of the race by connecting to topsrv (queuing accept work) and destroying their network namespace; pending work flushed after listener is nulled makes the crash reliably triggerable.\nPR:L - An unprivileged user can create a user+network namespace, use AF_TIPC with no capability checks to connect to topsrv, and tear down the netns to hit tipc_topsrv_stop—matching other tipc topsrv netns races scored PR:L.\nUI:N - No victim action is required; the attacker unilaterally opens connections and exits the network namespace.\nS:U - Impact is confined to the host kernel authority (DoS or local privilege escalation via UAF); there is no VM/IOMMU/sandbox boundary crossing.\nC:H - Vulnerable tipc_topsrv_stop() calls sock_release() on the listener before tipc_topsrv_work_stop(), so a concurrent tipc_topsrv_accept can use the freed socket—a UAF that enables info disclosure primitives.\nI:H - The same listener-socket UAF (explicitly fixed by deferring sock_release until after the accept worker finishes) can be exploited for heap reuse and arbitrary write/control-flow hijacking.\nA:H - The NULL deref and UAF paths both cause a kernel oops/panic in the tipc_rcv workqueue, fully disrupting system availability." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/tipc/topsrv.c" ], "versions": [ { "version": "0ef897be12b8b4cf297b6016e79ec97ec90f2cf6", "lessThan": "ce69bdac2310152bb70845024d5d704c52aabfc3", "status": "affected", "versionType": "git" }, { "version": "0ef897be12b8b4cf297b6016e79ec97ec90f2cf6", "lessThan": "24b129aed8730e48f47d852d58d76825ab6f407c", "status": "affected", "versionType": "git" }, { "version": "0ef897be12b8b4cf297b6016e79ec97ec90f2cf6", "lessThan": "32a3d4660b34ce49ac0162338ebe362098e2f5df", "status": "affected", "versionType": "git" }, { "version": "0ef897be12b8b4cf297b6016e79ec97ec90f2cf6", "lessThan": "7a939503fc32bff4ed60800b73ff7fbb4aea2142", "status": "affected", "versionType": "git" }, { "version": "0ef897be12b8b4cf297b6016e79ec97ec90f2cf6", "lessThan": "cedb41664e27b2cae7e21487f1bee22dcd84037d", "status": "affected", "versionType": "git" }, { "version": "0ef897be12b8b4cf297b6016e79ec97ec90f2cf6", "lessThan": "82cb4e4612c633a9ce320e1773114875604a3cce", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/tipc/topsrv.c" ], "versions": [ { "version": "4.17", "status": "affected" }, { "version": "0", "lessThan": "4.17", "status": "unaffected", "versionType": "semver" }, { "version": "4.19.264", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.223", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.153", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.77", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.0.7", "lessThanOrEqual": "6.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "4.19.264" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "5.4.223" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "5.10.153" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "5.15.77" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "6.0.7" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "6.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/ce69bdac2310152bb70845024d5d704c52aabfc3" }, { "url": "https://git.kernel.org/stable/c/24b129aed8730e48f47d852d58d76825ab6f407c" }, { "url": "https://git.kernel.org/stable/c/32a3d4660b34ce49ac0162338ebe362098e2f5df" }, { "url": "https://git.kernel.org/stable/c/7a939503fc32bff4ed60800b73ff7fbb4aea2142" }, { "url": "https://git.kernel.org/stable/c/cedb41664e27b2cae7e21487f1bee22dcd84037d" }, { "url": "https://git.kernel.org/stable/c/82cb4e4612c633a9ce320e1773114875604a3cce" } ], "title": "tipc: fix a null-ptr-deref in tipc_topsrv_accept", "x_generator": { "engine": "bippy-1.2.0" } } } }