Summary
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: SCO: Fix UAF on...
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: SCO: Fix UAF on sco_conn_free
BUG: KASAN: slab-use-after-free in sco_conn_free net/bluetooth/sco.c:87 [inline]
BUG: KASAN: slab-use-after-free in kref_put include/linux/kref.h:65 [inline]
BUG: KASAN: slab-use-after-free in sco_conn_put+0xdd/0x410
net/bluetooth/sco.c:107
Write of size 8 at addr ffff88811cb96b50 by task kworker/u17:4/352
CPU: 1 UID: 0 PID: 352 Comm: kworker/u17:4 Not tainted
6.17.0-rc5-g717368f83676 #4 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Workqueue: hci13 hci_cmd_sync_work
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x10b/0x170 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x191/0x550 mm/kasan/report.c:482
kasan_report+0xc4/0x100 mm/kasan/report.c:595
sco_conn_free net/bluetooth/sco.c:87 [inline]
kref_put include/linux/kref.h:65 [inline]
sco_conn_put+0xdd/0x410 net/bluetooth/sco.c:107
sco_connect_cfm+0xb4/0xae0 net/bluetooth/sco.c:1441
hci_connect_cfm include/net/bluetooth/hci_core.h:2082 [inline]
hci_conn_failed+0x20a/0x2e0 net/bluetooth/hci_conn.c:1313
hci_conn_unlink+0x55f/0x810 net/bluetooth/hci_conn.c:1121
hci_conn_del+0xb6/0x1110 net/bluetooth/hci_conn.c:1147
hci_abort_conn_sync+0x8c5/0xbb0 net/bluetooth/hci_sync.c:5689
hci_cmd_sync_work+0x281/0x380 net/bluetooth/hci_sync.c:332
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0x77e/0x1040 kernel/workqueue.c:3319
worker_thread+0xbee/0x1200 kernel/workqueue.c:3400
kthread+0x3c7/0x870 kernel/kthread.c:463
ret_from_fork+0x13a/0x1e0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Allocated by task 31370:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x30/0x70 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:388 [inline]
__kasan_kmalloc+0x82/0x90 mm/kasan/common.c:405
kasan_kmalloc include/linux/kasan.h:260 [inline]
__do_kmalloc_node mm/slub.c:4382 [inline]
__kmalloc_noprof+0x22f/0x390 mm/slub.c:4394
kmalloc_noprof include/linux/slab.h:909 [inline]
sk_prot_alloc+0xae/0x220 net/core/sock.c:2239
sk_alloc+0x34/0x5a0 net/core/sock.c:2295
bt_sock_alloc+0x3c/0x330 net/bluetooth/af_bluetooth.c:151
sco_sock_alloc net/bluetooth/sco.c:562 [inline]
sco_sock_create+0xc0/0x350 net/bluetooth/sco.c:593
bt_sock_create+0x161/0x3b0 net/bluetooth/af_bluetooth.c:135
__sock_create+0x3ad/0x780 net/socket.c:1589
sock_create net/socket.c:1647 [inline]
__sys_socket_create net/socket.c:1684 [inline]
__sys_socket+0xd5/0x330 net/socket.c:1731
__do_sys_socket net/socket.c:1745 [inline]
__se_sys_socket net/socket.c:1743 [inline]
__x64_sys_socket+0x7a/0x90 net/socket.c:1743
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xc7/0x240 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 31374:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x30/0x70 mm/kasan/common.c:68
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:243 [inline]
__kasan_slab_free+0x3d/0x50 mm/kasan/common.c:275
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2428 [inline]
slab_free mm/slub.c:4701 [inline]
kfree+0x199/0x3b0 mm/slub.c:4900
sk_prot_free net/core/sock.c:2278 [inline]
__sk_destruct+0x4aa/0x630 net/core/sock.c:2373
sco_sock_release+0x2ad/0x300 net/bluetooth/sco.c:1333
__sock_release net/socket.c:649 [inline]
sock_close+0xb8/0x230 net/socket.c:1439
__fput+0x3d1/0x9e0 fs/file_table.c:468
task_work_run+0x206/0x2a0 kernel/task_work.c:227
get_signal+0x1201/0x1410 kernel/signal.c:2807
arch_do_signal_or_restart+0x34/0x740 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x68/0xc0 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
s
---truncated---
Impact
CVE-2025-40309 has a CVSS score of 8.0 (High). The vector is reachable from an adjacent network, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. No fixed version is listed yet, so configuration controls and monitoring matter more in the interim.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2025-40309? CVE-2025-40309 is a high-severity security vulnerability. No fixed version is listed yet.
- How severe is CVE-2025-40309? CVE-2025-40309 has a CVSS score of 8.0 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Is there a fix for CVE-2025-40309? No fixed version is listed for CVE-2025-40309 yet. Monitor the advisory for updates and apply mitigations in the interim.
- Is CVE-2025-40309 exploitable, and should I be worried? Whether CVE-2025-40309 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-40309 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.