CVE-2025-39860

Source
https://cve.org/CVERecord?id=CVE-2025-39860
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-39860.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2025-39860
Downstream
AZL (2)
BELL (1)
CLSA (6)
DEBIAN (1)
ECHO (1)
OESA (4)
openSUSE (1)
ROOT (3)
SUSE (19)
UBUNTU (1)
Related
Published
2025-09-19T15:26:30Z
Modified
2026-10-20T10:30:24Z
Severity
  • 8.0 (High) CVSS_V3 - CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
Bluetooth: Fix use-after-free in l2cap_sock_cleanup_listen()
Details

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: Fix use-after-free in l2cap_sock_cleanup_listen()

syzbot reported the splat below without a repro.

In the splat, a single thread calling bt_accept_dequeue() freed sk and touched it after that.

The root cause would be the racy l2cap_sock_cleanup_listen() call added by the cited commit.

bt_accept_dequeue() is called under lock_sock() except for l2cap_sock_release().

Two threads could see the same socket during the list iteration in bt_accept_dequeue():

CPU1 CPU2 (close())


sock_hold(sk) sock_hold(sk); lock_sock(sk) <-- block close() sock_put(sk) bt_accept_unlink(sk) sock_put(sk) <-- refcnt by bt_accept_enqueue() release_sock(sk) lock_sock(sk) sock_put(sk) bt_accept_unlink(sk) sock_put(sk) <-- last refcnt bt_accept_unlink(sk) <-- UAF

Depending on the timing, the other thread could show up in the "Freed by task" part.

Let's call l2cap_sock_cleanup_listen() under lock_sock() in l2cap_sock_release().

[0]: BUG: KASAN: slab-use-after-free in debug_spin_lock_before kernel/locking/spinlock_debug.c:86 [inline] BUG: KASAN: slab-use-after-free in do_raw_spin_lock+0x26f/0x2b0 kernel/locking/spinlock_debug.c:115 Read of size 4 at addr ffff88803b7eb1c4 by task syz.5.3276/16995 CPU: 3 UID: 0 PID: 16995 Comm: syz.5.3276 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 debug_spin_lock_before kernel/locking/spinlock_debug.c:86 [inline] do_raw_spin_lock+0x26f/0x2b0 kernel/locking/spinlock_debug.c:115 spin_lock_bh include/linux/spinlock.h:356 [inline] release_sock+0x21/0x220 net/core/sock.c:3746 bt_accept_dequeue+0x505/0x600 net/bluetooth/af_bluetooth.c:312 l2cap_sock_cleanup_listen+0x5c/0x2a0 net/bluetooth/l2cap_sock.c:1451 l2cap_sock_release+0x5c/0x210 net/bluetooth/l2cap_sock.c:1425 __sock_release+0xb3/0x270 net/socket.c:649 sock_close+0x1c/0x30 net/socket.c:1439 __fput+0x3ff/0xb70 fs/file_table.c:468 task_work_run+0x14d/0x240 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2accf8ebe9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffdb6cb1378 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00000000000426fb RCX: 00007f2accf8ebe9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f2acd1b7da0 R08: 0000000000000001 R09: 00000012b6cb166f R10: 0000001b30e20000 R11: 0000000000000246 R12: 00007f2acd1b609c R13: 00007f2acd1b6090 R14: ffffffffffffffff R15: 00007ffdb6cb1490

Allocated by task 5326: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:388 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:405 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4365 [inline] __kmalloc_nopro ---truncated---

Database specific
{
    "cna_assigner":  "Linux",
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39860.json"
}
References

Affected packages

Git / 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
a2da00d1ea1abfb04f846638e210b5b5166e3c9c
Fixed
964cbb198f9c46c2b2358cd1faffc04c1e8248cf
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
06f87c96216bc5cd1094c23492274f77f1d5dd3b
Fixed
83e1d9892ef51785cf0760b7681436760dda435a
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
fbe5a2fed8156cc19eb3b956602b0a1dd46a302d
Fixed
47f6090bcf75c369695d21c3f179db8a56bbbd49
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
29fac18499332211b2615ade356e2bd8b3269f98
Fixed
2ca99fc3512a8074de20ee52a87b492dfcc41a4d
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
1728137b33c00d5a2b5110ed7aafb42e7c32e4a1
Fixed
6077d16b5c0f65d571eee709de2f0541fb5ef0ca
Fixed
306b0991413b482dbf5585b423022123bb505966
Fixed
3dff390f55ccd9ce12e91233849769b5312180c2
Fixed
862c628108562d8c7a516a900034823b381d3cba
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
5.4.253
Fixed
5.4.299
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
5.10.190
Fixed
5.10.243
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
5.15.126
Fixed
5.15.192
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
6.1.45
Fixed
6.1.151
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
4.14.322
Fixed
4.15
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
4.19.291
Fixed
4.20
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
6.4.10
Fixed
6.5
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
51822644a047eac2310fab0799b64e3430b5a111
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
82cdb2ccbe43337798393369f0ceb98699fe6037
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
10426afe65c8bf7b24dd0c7be4dcc65f86fc99f9

Affected versions

v4.*
v4.14.322
v4.14.323
v4.14.324
v4.14.325
v4.14.326
v4.14.327
v4.14.328
v4.14.329
v4.14.330
v4.14.331
v4.14.332
v4.14.333
v4.14.334
v4.14.335
v4.14.336
v4.19.291
v4.19.292
v4.19.293
v4.19.294
v4.19.295
v4.19.296
v4.19.297
v4.19.298
v4.19.299
v4.19.300
v4.19.301
v4.19.302
v4.19.303
v4.19.304
v4.19.305
v4.19.306
v4.19.307
v4.19.308
v4.19.309
v4.19.310
v4.19.311
v4.19.312
v4.19.313
v4.19.314
v4.19.315
v4.19.316
v4.19.317
v4.19.318
v4.19.319
v4.19.320
v4.19.321
v4.19.322
v4.19.323
v4.19.324
v4.19.325
v5.*
v5.10.190
v5.10.191
v5.10.192
v5.10.193
v5.10.194
v5.10.195
v5.10.196
v5.10.197
v5.10.198
v5.10.199
v5.10.200
v5.10.201
v5.10.202
v5.10.203
v5.10.204
v5.10.205
v5.10.206
v5.10.207
v5.10.208
v5.10.209
v5.10.210
v5.10.211
v5.10.212
v5.10.213
v5.10.214
v5.10.215
v5.10.216
v5.10.217
v5.10.218
v5.10.219
v5.10.220
v5.10.221
v5.10.222
v5.10.223
v5.10.224
v5.10.225
v5.10.226
v5.10.227
v5.10.228
v5.10.229
v5.10.230
v5.10.231
v5.10.232
v5.10.233
v5.10.234
v5.10.235
v5.10.236
v5.10.237
v5.10.238
v5.10.239
v5.10.240
v5.10.241
v5.10.242
v5.15.126
v5.15.127
v5.15.128
v5.15.129
v5.15.130
v5.15.131
v5.15.132
v5.15.133
v5.15.134
v5.15.135
v5.15.136
v5.15.137
v5.15.138
v5.15.139
v5.15.140
v5.15.141
v5.15.142
v5.15.143
v5.15.144
v5.15.145
v5.15.146
v5.15.147
v5.15.148
v5.15.149
v5.15.150
v5.15.151
v5.15.152
v5.15.153
v5.15.154
v5.15.155
v5.15.156
v5.15.157
v5.15.158
v5.15.159
v5.15.160
v5.15.161
v5.15.162
v5.15.163
v5.15.164
v5.15.165
v5.15.166
v5.15.167
v5.15.168
v5.15.169
v5.15.170
v5.15.171
v5.15.172
v5.15.173
v5.15.174
v5.15.175
v5.15.176
v5.15.177
v5.15.178
v5.15.179
v5.15.180
v5.15.181
v5.15.182
v5.15.183
v5.15.184
v5.15.185
v5.15.186
v5.15.187
v5.15.188
v5.15.189
v5.15.190
v5.15.191
v5.4.253
v5.4.254
v5.4.255
v5.4.256
v5.4.257
v5.4.258
v5.4.259
v5.4.260
v5.4.261
v5.4.262
v5.4.263
v5.4.264
v5.4.265
v5.4.266
v5.4.267
v5.4.268
v5.4.269
v5.4.270
v5.4.271
v5.4.272
v5.4.273
v5.4.274
v5.4.275
v5.4.276
v5.4.277
v5.4.278
v5.4.279
v5.4.280
v5.4.281
v5.4.282
v5.4.283
v5.4.284
v5.4.285
v5.4.286
v5.4.287
v5.4.288
v5.4.289
v5.4.290
v5.4.291
v5.4.292
v5.4.293
v5.4.294
v5.4.295
v5.4.296
v5.4.297
v5.4.298
v6.*
v6.1.100
v6.1.101
v6.1.102
v6.1.103
v6.1.104
v6.1.105
v6.1.106
v6.1.107
v6.1.108
v6.1.109
v6.1.110
v6.1.111
v6.1.112
v6.1.113
v6.1.114
v6.1.115
v6.1.116
v6.1.117
v6.1.118
v6.1.119
v6.1.120
v6.1.121
v6.1.122
v6.1.123
v6.1.124
v6.1.125
v6.1.126
v6.1.127
v6.1.128
v6.1.129
v6.1.130
v6.1.131
v6.1.132
v6.1.133
v6.1.134
v6.1.135
v6.1.136
v6.1.137
v6.1.138
v6.1.139
v6.1.140
v6.1.141
v6.1.142
v6.1.143
v6.1.144
v6.1.145
v6.1.146
v6.1.147
v6.1.148
v6.1.149
v6.1.150
v6.1.45
v6.1.46
v6.1.47
v6.1.48
v6.1.49
v6.1.50
v6.1.51
v6.1.52
v6.1.53
v6.1.54
v6.1.55
v6.1.56
v6.1.57
v6.1.58
v6.1.59
v6.1.60
v6.1.61
v6.1.62
v6.1.63
v6.1.64
v6.1.65
v6.1.66
v6.1.67
v6.1.68
v6.1.69
v6.1.70
v6.1.71
v6.1.72
v6.1.73
v6.1.74
v6.1.75
v6.1.76
v6.1.77
v6.1.78
v6.1.79
v6.1.80
v6.1.81
v6.1.82
v6.1.83
v6.1.84
v6.1.85
v6.1.86
v6.1.87
v6.1.88
v6.1.89
v6.1.90
v6.1.91
v6.1.92
v6.1.93
v6.1.94
v6.1.95
v6.1.96
v6.1.97
v6.1.98
v6.1.99
v6.4.10
v6.4.11
v6.4.12
v6.4.13
v6.4.14
v6.4.15
v6.4.16

Database specific

source
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-39860.json"

Linux / Kernel

Package

Name
Kernel

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
5.4.299
Type
ECOSYSTEM
Events
Introduced
5.5.0
Fixed
5.10.243
Type
ECOSYSTEM
Events
Introduced
5.11.0
Fixed
5.15.192
Type
ECOSYSTEM
Events
Introduced
5.16.0
Fixed
6.1.151
Type
ECOSYSTEM
Events
Introduced
6.2.0
Fixed
6.6.105
Type
ECOSYSTEM
Events
Introduced
6.5.0
Fixed
6.12.46
Type
ECOSYSTEM
Events
Introduced
6.7.0
Fixed
6.16.6

Database specific

source
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-39860.json"