{ "data_version": "4.0", "data_type": "CVE", "data_format": "MITRE", "CVE_data_meta": { "ID": "CVE-2024-26923", "ASSIGNER": "cve@kernel.org", "STATE": "PUBLIC" }, "description": { "description_data": [ { "lang": "eng", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\naf_unix: Fix garbage collector racing against connect()\n\nGarbage collector does not take into account the risk of embryo getting\nenqueued during the garbage collection. If such embryo has a peer that\ncarries SCM_RIGHTS, two consecutive passes of scan_children() may see a\ndifferent set of children. Leading to an incorrectly elevated inflight\ncount, and then a dangling pointer within the gc_inflight_list.\n\nsockets are AF_UNIX/SOCK_STREAM\nS is an unconnected socket\nL is a listening in-flight socket bound to addr, not in fdtable\nV's fd will be passed via sendmsg(), gets inflight count bumped\n\nconnect(S, addr)\tsendmsg(S, [V]); close(V)\t__unix_gc()\n----------------\t-------------------------\t-----------\n\nNS = unix_create1()\nskb1 = sock_wmalloc(NS)\nL = unix_find_other(addr)\nunix_state_lock(L)\nunix_peer(S) = NS\n\t\t\t// V count=1 inflight=0\n\n \t\t\tNS = unix_peer(S)\n \t\t\tskb2 = sock_alloc()\n\t\t\tskb_queue_tail(NS, skb2[V])\n\n\t\t\t// V became in-flight\n\t\t\t// V count=2 inflight=1\n\n\t\t\tclose(V)\n\n\t\t\t// V count=1 inflight=1\n\t\t\t// GC candidate condition met\n\n\t\t\t\t\t\tfor u in gc_inflight_list:\n\t\t\t\t\t\t if (total_refs == inflight_refs)\n\t\t\t\t\t\t add u to gc_candidates\n\n\t\t\t\t\t\t// gc_candidates={L, V}\n\n\t\t\t\t\t\tfor u in gc_candidates:\n\t\t\t\t\t\t scan_children(u, dec_inflight)\n\n\t\t\t\t\t\t// embryo (skb1) was not\n\t\t\t\t\t\t// reachable from L yet, so V's\n\t\t\t\t\t\t// inflight remains unchanged\n__skb_queue_tail(L, skb1)\nunix_state_unlock(L)\n\t\t\t\t\t\tfor u in gc_candidates:\n\t\t\t\t\t\t if (u.inflight)\n\t\t\t\t\t\t scan_children(u, inc_inflight_move_tail)\n\n\t\t\t\t\t\t// V count=1 inflight=2 (!)\n\nIf there is a GC-candidate listening socket, lock/unlock its state. This\nmakes GC wait until the end of any ongoing connect() to that socket. After\nflipping the lock, a possibly SCM-laden embryo is already enqueued. And if\nthere is another embryo coming, it can not possibly carry SCM_RIGHTS. At\nthis point, unix_inflight() can not happen because unix_gc_lock is already\ntaken. Inflight graph remains unaffected." } ] }, "problemtype": { "problemtype_data": [ { "description": [ { "lang": "eng", "value": "n/a" } ] } ] }, "affects": { "vendor": { "vendor_data": [ { "vendor_name": "Linux", "product": { "product_data": [ { "product_name": "Linux", "version": { "version_data": [ { "version_affected": "<", "version_name": "1fd05ba5a2f2", "version_value": "a36ae0ec2353" }, { "version_value": "not down converted", "x_cve_json_5_version_data": { "versions": [ { "version": "2.6.23", "status": "affected" }, { "version": "0", "lessThan": "2.6.23", "status": "unaffected", "versionType": "custom" }, { "version": "4.19.314", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "custom" }, { "version": "5.4.275", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "custom" }, { "version": "5.10.216", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "custom" }, { "version": "5.15.156", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.1.87", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.6.28", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.8.7", "lessThanOrEqual": "6.8.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.9", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ], "defaultStatus": "affected" } } ] } } ] } } ] } }, "references": { "reference_data": [ { "url": "https://git.kernel.org/stable/c/a36ae0ec2353015f0f6762e59f4c2dbc0c906423", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/a36ae0ec2353015f0f6762e59f4c2dbc0c906423" }, { "url": "https://git.kernel.org/stable/c/343c5372d5e17b306db5f8f3c895539b06e3177f", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/343c5372d5e17b306db5f8f3c895539b06e3177f" }, { "url": "https://git.kernel.org/stable/c/2e2a03787f4f0abc0072350654ab0ef3324d9db3", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/2e2a03787f4f0abc0072350654ab0ef3324d9db3" }, { "url": "https://git.kernel.org/stable/c/e76c2678228f6aec74b305ae30c9374cc2f28a51", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/e76c2678228f6aec74b305ae30c9374cc2f28a51" }, { "url": "https://git.kernel.org/stable/c/b75722be422c276b699200de90527d01c602ea7c", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/b75722be422c276b699200de90527d01c602ea7c" }, { "url": "https://git.kernel.org/stable/c/507cc232ffe53a352847893f8177d276c3b532a9", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/507cc232ffe53a352847893f8177d276c3b532a9" }, { "url": "https://git.kernel.org/stable/c/dbdf7bec5c920200077d693193f989cb1513f009", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/dbdf7bec5c920200077d693193f989cb1513f009" }, { "url": "https://git.kernel.org/stable/c/47d8ac011fe1c9251070e1bd64cb10b48193ec51", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/47d8ac011fe1c9251070e1bd64cb10b48193ec51" }, { "url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html", "refsource": "MISC", "name": "https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html" }, { "url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html", "refsource": "MISC", "name": "https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html" } ] }, "generator": { "engine": "bippy-a5840b7849dd" } }