{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-74302", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.882Z", "datePublished": "2026-08-15T05:58:04.638Z", "dateUpdated": "2026-08-17T05:45:38.299Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:45:38.299Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_core: Fix UAF in hci_unregister_dev()\n\nhci_unregister_dev() does not disable cmd_timer and ncmd_timer\nbefore the hci_dev structure is freed. If a timeout fires\nduring device teardown, the callback dereferences freed memory\n(including the hdev->reset function pointer), leading to a\nuse-after-free.\n\nAdd disable_delayed_work_sync() calls alongside the existing\ndisable_work_sync() calls to ensure both timers are fully\nquiesced before teardown proceeds." } ], "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 UAF is reached only during hci_unregister_dev() teardown (e.g. closing /dev/vhci, USB/btusb disconnect, hci_ldisc detach, or driver removal); adjacent Bluetooth peers can arm cmd_timer/ncmd_timer via HCI timeouts but cannot invoke unregister, so exploitation requires local device/syscall access.\nAC:L - An attacker controls both sides of the race—arming cmd_timer (2s) or ncmd_timer (4s) by withholding HCI command completions while closing /dev/vhci to run hci_unregister_dev(), and disable_work_sync(cmd_work) can queue cmd_timer immediately before teardown; the cycle is repeatable.\nPR:L - vhci_open() has no capable() check, so any principal granted /dev/vhci (syzkaller, containers, Android bluetooth uid, permissive udev) can create/destroy virtual HCI controllers and inject frames without init-namespace root, matching prior hci_unregister_dev teardown UAF scores.\nUI:N - The attacker performs device creation, HCI traffic injection, and teardown from its own process via open/write/close on /dev/vhci or equivalent local transport; no victim interaction or cooperation is required beyond existing device-node access.\nS:U - Corruption is confined to kernel slab memory and workqueue/timer state within the same kernel security authority; exploitation yields standard kernel privilege escalation, not VM escape, IOMMU bypass, or cross-sandbox boundary crossing.\nC:H - hci_cmd_timeout() and hci_ncmd_timeout() dereference the freed hci_dev (req_skb, flags, workqueue, name) after kfree(); UAF on the hci_dev slab enables controlled reallocation and arbitrary kernel memory read/pointer disclosure via heap spraying.\nI:H - hci_cmd_timeout() invokes the freed hdev->reset function pointer and re-queues cmd_work on hdev->workqueue; attacker-controlled contents in the reclaimed hci_dev object provide arbitrary write and control-flow hijack primitives per kernel UAF scoring guidance.\nA:H - Timer callbacks operating on freed hci_dev memory cause KASAN slab-use-after-free reports, kernel oops/panic, and can queue work onto destroyed workqueues; even failed exploitation reliably crashes or hangs the affected controller path." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/bluetooth/hci_core.c" ], "versions": [ { "version": "0d151a103775dd9645c78c97f77d6e2a5298d913", "lessThan": "48c7ad6afcc58c2cda11fed39791708103b6a644", "status": "affected", "versionType": "git" }, { "version": "0d151a103775dd9645c78c97f77d6e2a5298d913", "lessThan": "a0fd1086a57b982f8c24ae4ab165c2af39fe1735", "status": "affected", "versionType": "git" }, { "version": "0d151a103775dd9645c78c97f77d6e2a5298d913", "lessThan": "672d52d9412252e61b8de8d773ccdf5a277cf540", "status": "affected", "versionType": "git" }, { "version": "0d151a103775dd9645c78c97f77d6e2a5298d913", "lessThan": "5edcc018fa6e80b2c478454a4a8229c23d67c181", "status": "affected", "versionType": "git" }, { "version": "48542881997e17b49dc16b93fe910e0cfcf7a9f9", "status": "affected", "versionType": "git" }, { "version": "9cfc84b1d464cc024286f42a090718f9067b80ed", "status": "affected", "versionType": "git" }, { "version": "ddeda6ca5f218b668b560d90fc31ae469adbfd92", "status": "affected", "versionType": "git" }, { "version": "d2ce562a5aff1dcd0c50d9808ea825ef90da909f", "status": "affected", "versionType": "git" }, { "version": "96600c2e5ee8213dbab5df1617293d8e847bb4fa", "status": "affected", "versionType": "git" }, { "version": "d6cbce18370641a21dd889e8613d8153df15eb39", "status": "affected", "versionType": "git" }, { "version": "3f939bd73fed12dddc2a32a76116c19ca47c7678", "status": "affected", "versionType": "git" }, { "version": "4.19.319", "lessThan": "4.20", "status": "affected", "versionType": "semver" }, { "version": "5.4.281", "lessThan": "5.5", "status": "affected", "versionType": "semver" }, { "version": "5.10.223", "lessThan": "5.11", "status": "affected", "versionType": "semver" }, { "version": "5.15.164", "lessThan": "5.16", "status": "affected", "versionType": "semver" }, { "version": "6.1.101", "lessThan": "6.2", "status": "affected", "versionType": "semver" }, { "version": "6.6.42", "lessThan": "6.7", "status": "affected", "versionType": "semver" }, { "version": "6.9.11", "lessThan": "6.10", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/bluetooth/hci_core.c" ], "versions": [ { "version": "6.10", "status": "affected" }, { "version": "0", "lessThan": "6.10", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.5", "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": "6.10", "versionEndExcluding": "6.12.97" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "7.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.19.319" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4.281" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10.223" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15.164" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1.101" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6.42" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9.11" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/48c7ad6afcc58c2cda11fed39791708103b6a644" }, { "url": "https://git.kernel.org/stable/c/a0fd1086a57b982f8c24ae4ab165c2af39fe1735" }, { "url": "https://git.kernel.org/stable/c/672d52d9412252e61b8de8d773ccdf5a277cf540" }, { "url": "https://git.kernel.org/stable/c/5edcc018fa6e80b2c478454a4a8229c23d67c181" } ], "title": "Bluetooth: hci_core: Fix UAF in hci_unregister_dev()", "x_generator": { "engine": "bippy-1.2.0" } } } }