{"id":"CVE-2023-53252","summary":"Bluetooth: use RCU for hci_conn_params and iterate safely in hci_sync","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: use RCU for hci_conn_params and iterate safely in hci_sync\n\nhci_update_accept_list_sync iterates over hdev-\u003epend_le_conns and\nhdev-\u003epend_le_reports, and waits for controller events in the loop body,\nwithout holding hdev lock.\n\nMeanwhile, these lists and the items may be modified e.g. by\nle_scan_cleanup. This can invalidate the list cursor or any other item\nin the list, resulting to invalid behavior (eg use-after-free).\n\nUse RCU for the hci_conn_params action lists. Since the loop bodies in\nhci_sync block and we cannot use RCU or hdev-\u003elock for the whole loop,\ncopy list items first and then iterate on the copy. Only the flags field\nis written from elsewhere, so READ_ONCE/WRITE_ONCE should guarantee we\nread valid values.\n\nFree params everywhere with hci_conn_params_free so the cleanup is\nguaranteed to be done properly.\n\nThis fixes the following, which can be triggered e.g. by BlueZ new\nmgmt-tester case \"Add + Remove Device Nowait - Success\", or by changing\nhci_le_set_cig_params to always return false, and running iso-tester:\n\n==================================================================\nBUG: KASAN: slab-use-after-free in hci_update_passive_scan_sync (net/bluetooth/hci_sync.c:2536 net/bluetooth/hci_sync.c:2723 net/bluetooth/hci_sync.c:2841)\nRead of size 8 at addr ffff888001265018 by task kworker/u3:0/32\n\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014\nWorkqueue: hci0 hci_cmd_sync_work\nCall Trace:\n\u003cTASK\u003e\ndump_stack_lvl (./arch/x86/include/asm/irqflags.h:134 lib/dump_stack.c:107)\nprint_report (mm/kasan/report.c:320 mm/kasan/report.c:430)\n? __virt_addr_valid (./include/linux/mmzone.h:1915 ./include/linux/mmzone.h:2011 arch/x86/mm/physaddr.c:65)\n? hci_update_passive_scan_sync (net/bluetooth/hci_sync.c:2536 net/bluetooth/hci_sync.c:2723 net/bluetooth/hci_sync.c:2841)\nkasan_report (mm/kasan/report.c:538)\n? hci_update_passive_scan_sync (net/bluetooth/hci_sync.c:2536 net/bluetooth/hci_sync.c:2723 net/bluetooth/hci_sync.c:2841)\nhci_update_passive_scan_sync (net/bluetooth/hci_sync.c:2536 net/bluetooth/hci_sync.c:2723 net/bluetooth/hci_sync.c:2841)\n? __pfx_hci_update_passive_scan_sync (net/bluetooth/hci_sync.c:2780)\n? mutex_lock (kernel/locking/mutex.c:282)\n? __pfx_mutex_lock (kernel/locking/mutex.c:282)\n? __pfx_mutex_unlock (kernel/locking/mutex.c:538)\n? __pfx_update_passive_scan_sync (net/bluetooth/hci_sync.c:2861)\nhci_cmd_sync_work (net/bluetooth/hci_sync.c:306)\nprocess_one_work (./arch/x86/include/asm/preempt.h:27 kernel/workqueue.c:2399)\nworker_thread (./include/linux/list.h:292 kernel/workqueue.c:2538)\n? __pfx_worker_thread (kernel/workqueue.c:2480)\nkthread (kernel/kthread.c:376)\n? __pfx_kthread (kernel/kthread.c:331)\nret_from_fork (arch/x86/entry/entry_64.S:314)\n\u003c/TASK\u003e\n\nAllocated by task 31:\nkasan_save_stack (mm/kasan/common.c:46)\nkasan_set_track (mm/kasan/common.c:52)\n__kasan_kmalloc (mm/kasan/common.c:374 mm/kasan/common.c:383)\nhci_conn_params_add (./include/linux/slab.h:580 ./include/linux/slab.h:720 net/bluetooth/hci_core.c:2277)\nhci_connect_le_scan (net/bluetooth/hci_conn.c:1419 net/bluetooth/hci_conn.c:1589)\nhci_connect_cis (net/bluetooth/hci_conn.c:2266)\niso_connect_cis (net/bluetooth/iso.c:390)\niso_sock_connect (net/bluetooth/iso.c:899)\n__sys_connect (net/socket.c:2003 net/socket.c:2020)\n__x64_sys_connect (net/socket.c:2027)\ndo_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)\nentry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)\n\nFreed by task 15:\nkasan_save_stack (mm/kasan/common.c:46)\nkasan_set_track (mm/kasan/common.c:52)\nkasan_save_free_info (mm/kasan/generic.c:523)\n__kasan_slab_free (mm/kasan/common.c:238 mm/kasan/common.c:200 mm/kasan/common.c:244)\n__kmem_cache_free (mm/slub.c:1807 mm/slub.c:3787 mm/slub.c:3800)\nhci_conn_params_del (net/bluetooth/hci_core.c:2323)\nle_scan_cleanup (net/bluetooth/hci_conn.c:202)\nprocess_one_work (./arch/x86/include/asm/preempt.\n---truncated---","modified":"2026-03-20T12:33:03.150064Z","published":"2025-09-15T14:46:21.720Z","related":["SUSE-SU-2025:03600-1","SUSE-SU-2025:03615-1","SUSE-SU-2025:03634-1","SUSE-SU-2025:20851-1","SUSE-SU-2025:20861-1","SUSE-SU-2025:20870-1","SUSE-SU-2025:20898-1","SUSE-SU-2025:3751-1","SUSE-SU-2025:3761-1","SUSE-SU-2025:4057-1","SUSE-SU-2025:4132-1","SUSE-SU-2025:4141-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53252.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/13ad45ad14df992a6754a130a19abc8c142d54e2"},{"type":"WEB","url":"https://git.kernel.org/stable/c/195ef75e19287b4bc413da3e3e3722b030ac881e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cef88a0fd8e9c2e838162fbb742b3e713b811a7e"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53252.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-53252"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"e8907f76544ffe225ab95d70f7313267b1d0c76d"},{"fixed":"13ad45ad14df992a6754a130a19abc8c142d54e2"},{"fixed":"cef88a0fd8e9c2e838162fbb742b3e713b811a7e"},{"fixed":"195ef75e19287b4bc413da3e3e3722b030ac881e"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2023-53252.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}