{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-80683", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-26T14:34:25.784Z", "datePublished": "2026-08-28T06:52:50.099Z", "dateUpdated": "2026-08-28T06:52:50.099Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-28T06:52:50.099Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: SCO: give the socket its own sco_conn reference\n\nsco_conn_del() drops a reference it does not own. It takes one transient\nreference via sco_conn_hold_unless_zero() and releases it with the\nsco_conn_put() that follows sco_sock_hold(); the additional put in the\n!sk branch releases a second one:\n\n conn = sco_conn_hold_unless_zero(conn);\n ...\n sk = sco_sock_hold(conn);\n sco_conn_unlock(conn);\n sco_conn_put(conn);\n\n if (!sk) {\n sco_conn_put(conn);\n return;\n }\n\nWhen close() races the controller's Disconnection Complete, sco_chan_del()\nclears conn->sk and drops the socket's reference while sco_conn_del() is\nrunning. sco_conn_del() then sees sk == NULL, its own put drops the count\nto zero and frees the conn, and the second put writes to the freed kref:\n\n BUG: KASAN: slab-use-after-free in sco_conn_put.part.0+0x1a/0x190\n Write of size 4 at addr ffff8881099dec74 by task kworker/u17:3/413\n Workqueue: hci1 hci_rx_work\n Call Trace:\n sco_conn_put.part.0+0x1a/0x190\n hci_disconn_complete_evt+0x1ee/0x3e0\n hci_event_packet+0x54a/0x650\n hci_rx_work+0x321/0x3d0\n Allocated by task 413:\n sco_conn_add+0x72/0x1a0\n sco_connect_cfm+0x88/0x670\n Freed by task 413:\n sco_conn_del.isra.0+0x3f/0xf0\n hci_disconn_complete_evt+0x1ee/0x3e0\n refcount_t: underflow; use-after-free.\n\nThe root cause is that the socket stores the connection without holding a\nreference of its own. __sco_chan_add() does:\n\n sco_pi(sk)->conn = conn;\n\nso the socket borrows whatever reference its caller happened to hold, and\nthe callers paper over that with ad-hoc holds and puts. Give the socket a\ncounted reference instead: __sco_chan_add() takes one and it is released\ntogether with the channel (sco_chan_del()) and in sco_sock_destruct().\nWith the socket holding its own reference, sco_conn_del() no longer needs\nthe extra put and the redundant hold in sco_conn_ready() goes away.\n\nMaking the socket own its reference means the connection is now actually\nfreed on the error paths of sco_connect() where it used to leak, which in\nturn runs sco_conn_free() and its hci_conn_drop(conn->hcon). To keep the\nhci_conn accounting balanced, make that ownership explicit as well:\nsco_conn_add() consumes one hci_conn reference and the sco_conn owns it for\nits lifetime. sco_connect() hands over the reference returned by\nhci_connect_sco() and no longer drops it on the error paths;\nsco_connect_cfm(), which is not given a reference, takes one with\nhci_conn_hold() before handing it to sco_conn_add() (and drops it again if\nthe allocation fails); and the explicit hci_conn_hold() in sco_conn_ready()\nis removed. Every reference then has a single, clear owner." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/bluetooth/sco.c" ], "versions": [ { "version": "e6720779ae612a14ac4ba7fe4fd5b27d900d932c", "lessThan": "a33bc07b4730b6cd5681ac77d18ae0de3e739690", "status": "affected", "versionType": "git" }, { "version": "e6720779ae612a14ac4ba7fe4fd5b27d900d932c", "lessThan": "8fe627192fa5da7157f9a48608f13c04b6373e43", "status": "affected", "versionType": "git" }, { "version": "e6720779ae612a14ac4ba7fe4fd5b27d900d932c", "lessThan": "abd93c85c8667add738ee82aeab95dd9fc8265a2", "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/sco.c" ], "versions": [ { "version": "6.13", "status": "affected" }, { "version": "0", "lessThan": "6.13", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.44", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.8", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "6.13", "versionEndExcluding": "6.18.44" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "7.1.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/a33bc07b4730b6cd5681ac77d18ae0de3e739690" }, { "url": "https://git.kernel.org/stable/c/8fe627192fa5da7157f9a48608f13c04b6373e43" }, { "url": "https://git.kernel.org/stable/c/abd93c85c8667add738ee82aeab95dd9fc8265a2" } ], "title": "Bluetooth: SCO: give the socket its own sco_conn reference", "x_generator": { "engine": "bippy-1.2.0" } } } }