{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-68085", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-30T09:28:09.367Z", "datePublished": "2026-08-10T11:51:39.079Z", "dateUpdated": "2026-08-17T04:58:33.786Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:58:33.786Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_uart: clear HCI_UART_SENDING when write_work is canceled\n\nHCI_UART_SENDING bit in tx_state means write_work is pending and blocks\nqueueing it again. Currently this bit is not cleared when canceling the\nwork in hci_uart_close(), which blocks future writes when device is\nreopened later if write_work was pending.\n\nFix by clearing HCI_UART_SENDING when canceling the work.\n\nAlso make clearing of tx_skb safe by using disable_work_sync +\nenable_work instead of just cancel_work_sync. hci_uart_flush() purges\nthe proto tx queue so we can cancel the pending write_work there,\ninstead of doing it just in hci_uart_close(). Re-enable and possibly\nrequeue the work after queue flush." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:A - The flaw is in the Bluetooth HCI UART TX teardown path; an adjacent Bluetooth peer can drive HCI traffic to keep write_work pending while privileged stack management (HCIDEVRESET/close during adapter recovery) executes hci_uart_close/flush.\nAC:L - An attacker controls both sides of the race by generating HCI TX to set HCI_UART_SENDING and concurrently triggering adapter close/reset (e.g., HCIDEVRESET), making the stuck-bit and tx_skb teardown races reliably reachable.\nPR:L - Direct exploitation requires CAP_NET_ADMIN to attach the N_HCI TTY line discipline and issue HCIDEVDOWN/HCIDEVRESET ioctls; this capability is available to unprivileged users inside user namespaces, not only init-namespace root.\nUI:N - No victim interaction is required beyond normal Bluetooth operation; exploitation is achieved through attacker-driven HCI traffic and adapter close/reset timing without the user opening files or confirming prompts.\nS:U - Impact is confined to kernel Bluetooth/UART state on the host (permanent TX failure or kernel crash); it does not cross a VM, container, or IOMMU security boundary to affect a different authority.\nC:H - The vulnerable hci_uart_flush path can race with protocol timers requeueing write_work, causing tx_skb double-free/UAF heap corruption that can expose kernel memory contents, not merely a functional TX stall.\nI:H - Concurrent flush and write_work on tx_skb enables heap corruption primitives typical of double-free/UAF bugs in the kernel slab allocator, which can be leveraged for arbitrary memory writes and code execution.\nA:H - Leaving HCI_UART_SENDING set after cancel permanently blocks all future Bluetooth transmissions after reopen until full teardown, and the tx_skb corruption race can trigger kernel oops/panic." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/bluetooth/hci_ldisc.c" ], "versions": [ { "version": "81c7a3c22a0f2808cf4ae0b4908f59763b23606d", "lessThan": "d52446b3e735cfdbdc2a58342163803bc2e64249", "status": "affected", "versionType": "git" }, { "version": "192cb0f1ca706d9a1bc36ae0ad5f666d1e4fd894", "lessThan": "b9dd39cf1667e378b25a082ca796d495d578c5d3", "status": "affected", "versionType": "git" }, { "version": "c1bb9336ae6b54a5f6a353c4bd4ed9a4307e429b", "lessThan": "714d861d35d937f23375a4517569b13917bbbe51", "status": "affected", "versionType": "git" }, { "version": "c1bb9336ae6b54a5f6a353c4bd4ed9a4307e429b", "lessThan": "1b0d946d6f08bd39211385bc703a440911b41e46", "status": "affected", "versionType": "git" }, { "version": "78aad93e938f013d9272fe0ee168f27883afa95c", "status": "affected", "versionType": "git" }, { "version": "e2d19969c8d9198ecc3090bcd5312ecd503a3339", "status": "affected", "versionType": "git" }, { "version": "c85cff648a2bc92322912db5f1727ad05afae7b6", "status": "affected", "versionType": "git" }, { "version": "9d20d48be2c4a071fb015eb09bda2cecd25daf34", "status": "affected", "versionType": "git" }, { "version": "7338031946bd06f6dff149e67b60c4cd083bfea8", "status": "affected", "versionType": "git" }, { "version": "6.12.92", "lessThan": "6.12.96", "status": "affected", "versionType": "semver" }, { "version": "6.18.34", "lessThan": "6.18.39", "status": "affected", "versionType": "semver" }, { "version": "5.10.258", "lessThan": "5.11", "status": "affected", "versionType": "semver" }, { "version": "5.15.209", "lessThan": "5.16", "status": "affected", "versionType": "semver" }, { "version": "6.1.175", "lessThan": "6.2", "status": "affected", "versionType": "semver" }, { "version": "6.6.142", "lessThan": "6.7", "status": "affected", "versionType": "semver" }, { "version": "7.0.11", "lessThan": "7.1", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/bluetooth/hci_ldisc.c" ], "versions": [ { "version": "7.1", "status": "affected" }, { "version": "0", "lessThan": "7.1", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.96", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.39", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.4", "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": "6.12.92", "versionEndExcluding": "6.12.96" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18.34", "versionEndExcluding": "6.18.39" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.1", "versionEndExcluding": "7.1.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.1", "versionEndExcluding": "7.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10.258" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15.209" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1.175" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6.142" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.0.11" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/d52446b3e735cfdbdc2a58342163803bc2e64249" }, { "url": "https://git.kernel.org/stable/c/b9dd39cf1667e378b25a082ca796d495d578c5d3" }, { "url": "https://git.kernel.org/stable/c/714d861d35d937f23375a4517569b13917bbbe51" }, { "url": "https://git.kernel.org/stable/c/1b0d946d6f08bd39211385bc703a440911b41e46" } ], "title": "Bluetooth: hci_uart: clear HCI_UART_SENDING when write_work is canceled", "x_generator": { "engine": "bippy-1.2.0" } } } }