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Fencer Vulns
high 8.0

CVE-2025-40309 json

Bluetooth: SCO: Fix UAF on sco_conn_free

published 2025-12-08 11 mo ago modified 2026-10-15 24 d ago also EUVD-2025-201636

cvss
8.0
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 18%
public exploits
0
none known

Summary

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: <TASK> __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 </TASK>

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---

Patch / fix

  • Linux Linux 6.17.8, 6.18
  • linux Debian 12 6.1.159-1
  • linux Debian 13 6.12.63-1
  • linux Debian 14 6.17.8-1

debian advisories DEBIAN-CVE-2025-40309

  • linux Ubuntu 25.10 6.17.0-14.14
  • linux-aws Ubuntu 25.10 6.17.0-1007.7
  • linux-gcp Ubuntu 25.10 6.17.0-1007.7
  • linux-azure Ubuntu 25.10 6.17.0-1008.8
  • linux-raspi Ubuntu 25.10 6.17.0-1008.8
  • linux-riscv Ubuntu 25.10 6.17.0-14.14.1
  • linux-oracle Ubuntu 25.10 6.17.0-1007.7
  • linux-aws-6.17 Ubuntu 24.04 LTS 6.17.0-1007.7~24.04.1

ubuntu advisories UBUNTU-CVE-2025-40309

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-livepatch-SLE16_Update_1 Linux Micro 6.2 8-160000.1.1
  • kernel-livepatch-SLE16_Update_0 Linux Micro 6.2 10-160000.4.3
  • kernel-livepatch-SLE16-RT_Update_1 Linux Micro 6.2 7-160000.1.1
  • kernel-livepatch-SLE16-RT_Update_0 Linux Micro 6.2 8-160000.3.4
  • kernel-livepatch-SLE16-RT_Update_2 Linux Micro 6.2 5-160000.1.1
  • kernel-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-40.1
  • kernel-source-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-40.1
  • kernel-source Linux Micro 6.1, Linux Micro 6.0 6.4.0-39.1

suse advisories SUSE-SU-2026:1613-1SUSE-SU-2026:1583-1SUSE-SU-2026:21279-1SUSE-SU-2026:21278-1SUSE-SU-2026:21270-1SUSE-SU-2026:21269-1

  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.9.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.9.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.9.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.9.1
  • kernel-azure openSUSE Leap 16.0 6.12.0-160000.9.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.9.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.9.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.9.1

opensuse advisories openSUSE-SU-2026:20145-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-40309 updated cvss 6.4

kernel: Bluetooth: SCO: Fix UAF on sco_conn_free

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
    affected: no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
24 d ago

Exploit prediction

0.26% chance of exploitation in the next 30 days, higher than 18% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.0 CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.