{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-99012", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.385Z", "datePublished": "2026-10-23T12:20:37.472Z", "dateUpdated": "2026-10-24T14:10:00.497Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-24T14:10:00.497Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: ISO: Serialize concurrent connect calls\n\niso_sock_connect() checks the socket state before taking the socket lock\nand drops the lock again before setting up a connection. Two callers can\nboth pass the admission check while the socket is open or bound.\n\nCaller A can copy its destination for route selection, then caller B can\nreplace the socket destination before A binds or connects the CIS. A\nthen uses B's destination with the route selected for its own request.\nB can also proceed after A attaches a connection and sets BT_CONNECT.\nFor deferred BIS setup, B can bind a second BIS and overwrite\niso_pi(sk)->conn, leaving the first connection's reference and conn->sk\nback-pointer stranded. Concurrent CIS connects can likewise replace the\nsocket's connection. Later teardown only detaches the current connection,\nso a callback on the old connection can race with socket release and\naccess a freed socket.\n\nKASAN reported:\n\n BUG: KASAN: slab-use-after-free in iso_sock_hold+0xf7/0x1b0\n Call Trace:\n iso_sock_hold+0xf7/0x1b0\n iso_conn_del+0x7b/0x1d0\n iso_connect_cfm+0x186/0x16a0\n hci_conn_failed+0x154/0x280\n hci_abort_conn_sync+0x3dc/0x7d0\n hci_cmd_sync_work+0x173/0x300\n\n Allocated by task 121:\n sk_alloc+0x2b/0x6d0\n bt_sock_alloc+0x29/0x370\n iso_sock_alloc.constprop.0+0x19/0x300\n iso_sock_create+0x94/0x100\n\n Freed by task 121:\n kfree+0x121/0x3c0\n __sk_destruct+0x42b/0x540\n iso_sock_release+0x29d/0x340\n __sock_release+0xa1/0x260\n\nCheck admission under the socket lock and mark the connect operation in\nprogress before publishing its destination. Keep that flag set across\nroute lookup and connection setup, rejecting another connect with\n-EBADFD before it can change the destination or attach a connection.\nClear the flag after either helper returns, including on failure, so a\nfailed setup can be retried.\n\nA separate flag is needed because the socket lock must be released before\nacquiring the HCI device lock, while BT_CONNECT requires an attached\nconnection. Keep the existing state transitions and the deferred CIS\ncompletion through iso_sock_recvmsg().\n\nReject an existing socket attachment in __iso_chan_add() before taking\na new reference or publishing either pointer, so every caller preserves\nthe connection association. Keep the same-socket, same-connection success\ncase for deferred CIS setup. Reject an attached socket before BIS setup\nso a reusable BIS is not claimed before the attachment is rejected.\n\nIn CIS setup, reject a different HCI connection before iso_conn_add()\nand drop the per-attempt HCI hold directly. An unowned iso_conn may still\ncarry another reference after detachment, so its destruction cannot be\nrelied on to release that hold.\n\niso_listen_bis() creates a fresh PA HCI/ISO pair under the device lock,\nso the temporary iso_conn_put() frees the ISO candidate and drops its\nHCI hold on rejection. iso_conn_ready() uses a freshly allocated,\nunpublished child with no connection, making the socket-side rejection\nunreachable." } ], "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 attack begins with two local connect(2) calls on one BTPROTO_ISO socket: __sys_connect() reaches iso_sock_connect(), whose pre-fix unlocked admission check lets both calls overwrite iso_pi(sk)->dst and attach different connections. No received Bluetooth message creates those concurrent calls or supplies the state that causes the overwrite.\nAC:L - A process controls both sides by sharing one socket between threads and issuing concurrent nonblocking connects; the patched BT_SK_CONNECTING flag exists solely to serialize those calls. The stranded conn->sk persists until connection failure or abort, so the attacker can retry and close or spray sockets without depending on victim activity.\nPR:L - bt_sock_create() and iso_sock_create() contain no capable() check, so an ordinary user in init_net can create the required AF_BLUETOOTH/SOCK_SEQPACKET/BTPROTO_ISO socket and call connect(). bt_sock_create() rejects non-initial network namespaces, but no administrative privilege is required in init_net.\nUI:N - The attacker creates, races, and closes their own ISO socket; subsequent hci_conn_failed() -> iso_connect_cfm() -> iso_conn_del() teardown is automatic and needs no victim action.\nS:U - The stale socket pointer is used and corrupted inside the host kernel's Bluetooth/socket memory, yielding an ordinary kernel compromise without crossing a VM, IOMMU, or separate security authority.\nC:H - The overwrite leaves the old iso_conn->sk pointing at a freed, kmalloc-backed struct iso_pinfo; iso_conn_del() passes it through iso_sock_hold() and then reads socket, timer, connection, parent, and callback fields. Controlled heap reclamation makes this kernel UAF usable for high-impact memory disclosure.\nI:H - Through stale conn->sk, iso_sock_hold() increments sk_refcnt and iso_conn_del()/iso_chan_del() manipulate the freed socket's lock, timer work, conn pointer, state, error, and callback. These writes into reclaimed heap memory support pointer/refcount corruption and control-flow hijacking.\nA:H - The commit's KASAN trace demonstrates a slab use-after-free in iso_sock_hold() reached through hci_conn_failed() -> iso_connect_cfm() -> iso_conn_del(); dereferencing or locking the freed struct sock can oops or panic the kernel." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/bluetooth/iso.c" ], "versions": [ { "version": "ccf74f2390d60a2f9a75ef496d2564abb478f46a", "lessThan": "9b6ed57eb8c892ee7566b8c1bd06fdd0053b53de", "status": "affected", "versionType": "git" }, { "version": "ccf74f2390d60a2f9a75ef496d2564abb478f46a", "lessThan": "1adcfe232c0f58890c2538211a841100ad0512bd", "status": "affected", "versionType": "git" }, { "version": "ccf74f2390d60a2f9a75ef496d2564abb478f46a", "lessThan": "c6489a3a0ac8c07f64cb5b44f005bc518f1048ac", "status": "affected", "versionType": "git" }, { "version": "ccf74f2390d60a2f9a75ef496d2564abb478f46a", "lessThan": "3728f6b0d5990c0d500e929ba10baf93bee24f5e", "status": "affected", "versionType": "git" }, { "version": "ccf74f2390d60a2f9a75ef496d2564abb478f46a", "lessThan": "e32d80293a0e1a160d5e5101daa8c82148c07510", "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/bluetooth/iso.c" ], "versions": [ { "version": "6.0", "status": "affected" }, { "version": "0", "lessThan": "6.0", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.113", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.57", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.11", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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": "6.0", "versionEndExcluding": "6.6.160" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.12.113" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.18.57" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "7.2.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/9b6ed57eb8c892ee7566b8c1bd06fdd0053b53de" }, { "url": "https://git.kernel.org/stable/c/1adcfe232c0f58890c2538211a841100ad0512bd" }, { "url": "https://git.kernel.org/stable/c/c6489a3a0ac8c07f64cb5b44f005bc518f1048ac" }, { "url": "https://git.kernel.org/stable/c/3728f6b0d5990c0d500e929ba10baf93bee24f5e" }, { "url": "https://git.kernel.org/stable/c/e32d80293a0e1a160d5e5101daa8c82148c07510" } ], "title": "Bluetooth: ISO: Serialize concurrent connect calls", "x_generator": { "engine": "bippy-1.2.0" } } } }