CVE-2026-64433
Analyzed
Analyzed - Analysis Complete
Use-After-Free in Linux Kernel Bluetooth MGMT
Vulnerability report for CVE-2026-64433, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-07-25
Last updated on: 2026-09-03
Assigner: kernel.org
Description
Description
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: MGMT: Fix UAF of hci_conn_params in add_device_complete
add_device_complete() runs from the hci_cmd_sync_work kworker, which
holds only hci_req_sync_lock and *not* hci_dev_lock. It calls
hci_conn_params_lookup() and then dereferences the returned object
(params->flags) without taking hci_dev_lock:
params = hci_conn_params_lookup(hdev, &cp->addr.bdaddr,
le_addr_type(cp->addr.type));
...
device_flags_changed(NULL, hdev, &cp->addr.bdaddr,
cp->addr.type, hdev->conn_flags,
params ? params->flags : 0);
hci_conn_params_lookup() walks hdev->le_conn_params and is documented to
require hdev->lock. A concurrent MGMT_OP_REMOVE_DEVICE
(remove_device()), which does run under hci_dev_lock, can call
hci_conn_params_free() to list_del() and kfree() the very object the
lookup returned, so the subsequent params->flags read touches freed
memory [0].
Hold hci_dev_lock() across the hci_conn_params_lookup() and the read of
params->flags (and the matching event emission) so the lookup result
cannot be freed by a concurrent remove_device() before it is used,
honouring the locking contract of hci_conn_params_lookup().
[0]: (trailing page/memory-state dump trimmed)
BUG: KASAN: slab-use-after-free in add_device_complete+0x358/0x3d8 net/bluetooth/mgmt.c:7671
Read of size 1 at addr ffff000017ab26c1 by task kworker/u9:8/388
CPU: 1 UID: 0 PID: 388 Comm: kworker/u9:8 Not tainted 7.0.11 #20 PREEMPT
Hardware name: linux,dummy-virt (DT)
Workqueue: hci0 hci_cmd_sync_work
Call trace:
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C)
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0xb4/0xd4 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x118/0x5d8 mm/kasan/report.c:482
kasan_report+0xb0/0xf4 mm/kasan/report.c:595
__asan_report_load1_noabort+0x20/0x2c mm/kasan/report_generic.c:378
add_device_complete+0x358/0x3d8 net/bluetooth/mgmt.c:7671
hci_cmd_sync_work+0x14c/0x240 net/bluetooth/hci_sync.c:334
process_one_work+0x628/0xd38 kernel/workqueue.c:3289
process_scheduled_works kernel/workqueue.c:3372 [inline]
worker_thread+0x7a8/0xac0 kernel/workqueue.c:3453
kthread+0x39c/0x444 kernel/kthread.c:436
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860
Allocated by task 3401:
kasan_save_stack+0x3c/0x64 mm/kasan/common.c:57
kasan_save_track+0x20/0x3c mm/kasan/common.c:78
kasan_save_alloc_info+0x40/0x54 mm/kasan/generic.c:570
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0xd4/0xd8 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_noprof+0x1b0/0x458 mm/slub.c:5385
kmalloc_noprof include/linux/slab.h:950 [inline]
kzalloc_noprof include/linux/slab.h:1188 [inline]
hci_conn_params_add+0x10c/0x4b0 net/bluetooth/hci_core.c:2279
hci_conn_params_set net/bluetooth/mgmt.c:5162 [inline]
add_device+0x5b4/0xa54 net/bluetooth/mgmt.c:7755
hci_mgmt_cmd net/bluetooth/hci_sock.c:1721 [inline]
hci_sock_sendmsg+0x10b4/0x1dd0 net/bluetooth/hci_sock.c:1841
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg+0xe0/0x128 net/socket.c:742
sock_write_iter+0x250/0x390 net/socket.c:1195
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x66c/0xab0 fs/read_write.c:688
ksys_write+0x1fc/0x24c fs/read_write.c:740
__do_sys_write fs/read_write.c:751 [inline]
__se_sys_write fs/read_write.c:748 [inline]
__arm64_sys_write+0x70/0xa4 fs/read_write.c:748
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x84/0x2a8 arch/arm64/kernel/syscall.c:49
el0_svc_common.constprop.0+0xe4/0x294 arch/arm64/kernel/syscall.c:132
do_el0_svc+0x44/0x5c arch/arm64/kernel/syscall.c:151
el0_svc+0x38/0xac arch/arm64/kernel/entry-common.c:724
el0t_64_sync_handler+0xa0/0xe4 arch/arm64/kernel/entry-common.c:743
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596
Freed by task 3740:
kasan_save_stack+0x3c/0x64
---truncated---
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | 6.15 |
| linux | linux_kernel | 6.15 |
| linux | linux_kernel | From 6.14.8 (inc) to 6.15 (exc) |
| linux | linux_kernel | From 6.19 (inc) to 7.1.4 (exc) |
| linux | linux_kernel | 7.2 |
| linux | linux_kernel | 7.2 |
| linux | linux_kernel | From 6.12.30 (inc) to 6.12.96 (exc) |
| linux | linux_kernel | From 6.15.1 (inc) to 6.18.39 (exc) |
| linux | linux_kernel | From 6.6.92 (inc) to 6.6.145 (exc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-416 | The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer. |
