{ "schema_version": "1.6.1", "id": "RPI-CVE-2023-53762", "modified": "2026-10-09T11:39:44Z", "upstream": [ "CVE-2023-53762" ], "published": "2025-12-08T01:19:54Z", "summary": "Bluetooth: hci_sync: Fix UAF in hci_disconnect_all_sync", "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_sync: Fix UAF in hci_disconnect_all_sync\n\nUse-after-free can occur in hci_disconnect_all_sync if a connection is\ndeleted by concurrent processing of a controller event.\n\nTo prevent this the code now tries to iterate over the list backwards\nto ensure the links are cleanup before its parents, also it no longer\nrelies on a cursor, instead it always uses the last element since\nhci_abort_conn_sync is guaranteed to call hci_conn_del.\n\nUAF crash log:\n==================================================================\nBUG: KASAN: slab-use-after-free in hci_set_powered_sync\n(net/bluetooth/hci_sync.c:5424) [bluetooth]\nRead of size 8 at addr ffff888009d9c000 by task kworker/u9:0/124\n\nCPU: 0 PID: 124 Comm: kworker/u9:0 Tainted: G W\n6.5.0-rc1+ #10\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS\n1.16.2-1.fc38 04/01/2014\nWorkqueue: hci0 hci_cmd_sync_work [bluetooth]\nCall Trace:\n \n dump_stack_lvl+0x5b/0x90\n print_report+0xcf/0x670\n ? __virt_addr_valid+0xdd/0x160\n ? hci_set_powered_sync+0x2c9/0x4a0 [bluetooth]\n kasan_report+0xa6/0xe0\n ? hci_set_powered_sync+0x2c9/0x4a0 [bluetooth]\n ? __pfx_set_powered_sync+0x10/0x10 [bluetooth]\n hci_set_powered_sync+0x2c9/0x4a0 [bluetooth]\n ? __pfx_hci_set_powered_sync+0x10/0x10 [bluetooth]\n ? __pfx_lock_release+0x10/0x10\n ? __pfx_set_powered_sync+0x10/0x10 [bluetooth]\n hci_cmd_sync_work+0x137/0x220 [bluetooth]\n process_one_work+0x526/0x9d0\n ? __pfx_process_one_work+0x10/0x10\n ? __pfx_do_raw_spin_lock+0x10/0x10\n ? mark_held_locks+0x1a/0x90\n worker_thread+0x92/0x630\n ? __pfx_worker_thread+0x10/0x10\n kthread+0x196/0x1e0\n ? __pfx_kthread+0x10/0x10\n ret_from_fork+0x2c/0x50\n \n\nAllocated by task 1782:\n kasan_save_stack+0x33/0x60\n kasan_set_track+0x25/0x30\n __kasan_kmalloc+0x8f/0xa0\n hci_conn_add+0xa5/0xa80 [bluetooth]\n hci_bind_cis+0x881/0x9b0 [bluetooth]\n iso_connect_cis+0x121/0x520 [bluetooth]\n iso_sock_connect+0x3f6/0x790 [bluetooth]\n __sys_connect+0x109/0x130\n __x64_sys_connect+0x40/0x50\n do_syscall_64+0x60/0x90\n entry_SYSCALL_64_after_hwframe+0x6e/0xd8\n\nFreed by task 695:\n kasan_save_stack+0x33/0x60\n kasan_set_track+0x25/0x30\n kasan_save_free_info+0x2b/0x50\n __kasan_slab_free+0x10a/0x180\n __kmem_cache_free+0x14d/0x2e0\n device_release+0x5d/0xf0\n kobject_put+0xdf/0x270\n hci_disconn_complete_evt+0x274/0x3a0 [bluetooth]\n hci_event_packet+0x579/0x7e0 [bluetooth]\n hci_rx_work+0x287/0xaa0 [bluetooth]\n process_one_work+0x526/0x9d0\n worker_thread+0x92/0x630\n kthread+0x196/0x1e0\n ret_from_fork+0x2c/0x50\n==================================================================", "severity": [ { "type": "CVSS_V3", "score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H" } ], "affected": [ { "package": { "ecosystem": "Raspberry Pi OS:12", "name": "linux" }, "versions": [ "1:6.1.21-1+rpt1", "1:6.1.47-1+rpt2", "1:6.1.47-1+rpt4", "1:6.1.54-1+rpt2", "1:6.1.58-1+rpt2", "1:6.1.63-1+rpt1", "1:6.1.73-1+rpt1" ], "ecosystem_specific": { "binaries": [ { "binary_name": "linux-image-6.1.0-rpi1-rpi-v6", "binary_version": "1:6.1.21-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi1-rpi-v7", "binary_version": "1:6.1.21-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi1-rpi-v7l", "binary_version": "1:6.1.21-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi1-rpi-v8", "binary_version": "1:6.1.21-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi2-rpi-v6", "binary_version": "1:6.1.47-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi2-rpi-v7", "binary_version": "1:6.1.47-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi2-rpi-v7l", "binary_version": "1:6.1.47-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi2-rpi-v8", "binary_version": "1:6.1.47-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-2712", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v6", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v8", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi4-rpi-2712", "binary_version": "1:6.1.54-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi4-rpi-v6", "binary_version": "1:6.1.54-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi4-rpi-v7", "binary_version": "1:6.1.54-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi4-rpi-v7l", "binary_version": "1:6.1.54-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi4-rpi-v8", "binary_version": "1:6.1.54-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi6-rpi-2712", "binary_version": "1:6.1.58-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi6-rpi-v6", "binary_version": "1:6.1.58-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi6-rpi-v7", "binary_version": "1:6.1.58-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi6-rpi-v7l", "binary_version": "1:6.1.58-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi6-rpi-v8", "binary_version": "1:6.1.58-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi7-rpi-2712", "binary_version": "1:6.1.63-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi7-rpi-v6", "binary_version": "1:6.1.63-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi7-rpi-v7", "binary_version": "1:6.1.63-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi7-rpi-v7l", "binary_version": "1:6.1.63-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi7-rpi-v8", "binary_version": "1:6.1.63-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi8-rpi-2712", "binary_version": "1:6.1.73-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi8-rpi-v6", "binary_version": "1:6.1.73-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi8-rpi-v7", "binary_version": "1:6.1.73-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi8-rpi-v7l", "binary_version": "1:6.1.73-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi8-rpi-v8", "binary_version": "1:6.1.73-1+rpt1" } ] }, "database_specific": { "per_version": { "1:6.1.21-1+rpt1": { "linux_commit": "0afb5e98488aed7017b9bf321b575d0177feb7ed", "upstream_version": "6.1.21", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.189" }, "1:6.1.47-1+rpt2": { "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e", "upstream_version": "6.1.47", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.189" }, "1:6.1.47-1+rpt4": { "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e", "upstream_version": "6.1.47", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.189", "compiled_filter": false }, "1:6.1.54-1+rpt2": { "linux_commit": "2906f7abdc03d4a92b6b0e2e0c87ea2a9dffe8f7", "upstream_version": "6.1.54", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.189" }, "1:6.1.58-1+rpt2": { "linux_commit": "ccf1586ad0663fa91238ac56abf6340d6d740d18", "upstream_version": "6.1.58", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.189" }, "1:6.1.63-1+rpt1": { "linux_commit": null, "upstream_version": "6.1.63", "assessment": "upstream version (no usable Linux commit)", "upstream_fixed": "6.1.189" }, "1:6.1.73-1+rpt1": { "linux_commit": null, "upstream_version": "6.1.73", "assessment": "upstream version (no usable Linux commit)", "upstream_fixed": "6.1.189" } } } } ], "references": [ { "type": "ADVISORY", "url": "https://www.cve.org/CVERecord?id=CVE-2023-53762" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/5e3ee972f185eb7957ce789b3bf13a3cb790f178" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/a30c074f0b5b7f909a15c978fbc96a29e2f94e42" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/ba3ba53ce1f76fc372b8f918fece4f9b1e41acd4" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/94d9ba9f9888b748d4abd2aa1547af56ae85f772" } ], "database_specific": { "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git", "upstream_modified": "2026-10-03T11:04:09Z", "severity": { "source": "kernel CNA", "cvss_v3_score": 8.8, "cvss_v3_severity": "High", "scenario": "AV:A - The freeing side of the race is `hci_disconn_complete_evt()` processed from HCI events generated by a peer Bluetooth device terminating a link or causing link-supervision timeout, so the attacker must be a device within Bluetooth radio range. Bluetooth reachability is scored Adjacent.\nAC:L - The attacker controls the free side entirely (link teardown timing and the multi-link ACL/SCO or LE/CIS topology that makes `hci_conn_unlink()` cascade a `hci_conn_del()` onto the loop's cached cursor), and the window is wide because `hci_disconnect_sync()` sleeps on `HCI_CMD_TIMEOUT` without waiting for Disconnect Complete. The victim-side trigger (adapter power-off or the routine autosuspend path via `hci_suspend_sync()`) recurs constantly, and attempts can be retried indefinitely.\nPR:N - The attacker needs no account, capability, or credential on the target host \u2014 only an in-range Bluetooth link, which for LE/L2CAP/CIS can be established without pairing. No local privilege on the victim is required to deliver the disconnect that frees the `hci_conn`.\nUI:N - `hci_disconnect_all_sync()` is reached automatically by `hci_suspend_sync()` on every system/auto suspend that has active connections, and by rfkill/adapter power-down performed by system daemons. No deliberate victim action is needed.\nS:U - The corruption stays within the kernel's own security authority; there is no crossing into a hypervisor, IOMMU, or other separate security scope.\nC:H - The freed `hci_conn` is read after free (`conn->state`, `conn->handle`, `conn->type`, `conn->dst`) from a sprayable general kmalloc cache, letting an attacker who reallocates the slot both leak kernel memory contents and steer subsequent reads for arbitrary disclosure.\nI:H - The dangling object is passed on to `hci_conn_failed()`/`hci_conn_del()`, which performs `list_del` on attacker-controlled list pointers (write primitive) and calls the `conn->cleanup(conn)` function pointer out of freed memory in `hci_conn_cleanup()`, giving control-flow hijack and privilege escalation potential.\nA:H - The confirmed KASAN slab-use-after-free in the `hci_cmd_sync_work` kernel worker crashes the kernel, and it can be re-triggered on every power-off/suspend cycle for persistent denial of service." } } }