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

Bluetooth: hci_sock: Prevent race in socket write iter and sock bind

There is a potential race condition between sock bind and socket write
iter. bind may free the same cmd via mgmt_pending before write iter sends
the cmd, just as syzbot reported in UAF[1].

Here we use hci_dev_lock to synchronize the two, thereby avoiding the
UAF mentioned in [1].

[1]
syzbot reported:
BUG: KASAN: slab-use-after-free in mgmt_pending_remove+0x3b/0x210 net/bluetooth/mgmt_util.c:316
Read of size 8 at addr ffff888077164818 by task syz.0.17/5989
Call Trace:
mgmt_pending_remove+0x3b/0x210 net/bluetooth/mgmt_util.c:316
set_link_security+0x5c2/0x710 net/bluetooth/mgmt.c:1918
hci_mgmt_cmd+0x9c9/0xef0 net/bluetooth/hci_sock.c:1719
hci_sock_sendmsg+0x6ca/0xef0 net/bluetooth/hci_sock.c:1839
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg+0x21c/0x270 net/socket.c:742
sock_write_iter+0x279/0x360 net/socket.c:1195

Allocated by task 5989:
mgmt_pending_add+0x35/0x140 net/bluetooth/mgmt_util.c:296
set_link_security+0x557/0x710 net/bluetooth/mgmt.c:1910
hci_mgmt_cmd+0x9c9/0xef0 net/bluetooth/hci_sock.c:1719
hci_sock_sendmsg+0x6ca/0xef0 net/bluetooth/hci_sock.c:1839
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg+0x21c/0x270 net/socket.c:742
sock_write_iter+0x279/0x360 net/socket.c:1195

Freed by task 5991:
mgmt_pending_free net/bluetooth/mgmt_util.c:311 [inline]
mgmt_pending_foreach+0x30d/0x380 net/bluetooth/mgmt_util.c:257
mgmt_index_removed+0x112/0x2f0 net/bluetooth/mgmt.c:9477
hci_sock_bind+0xbe9/0x1000 net/bluetooth/hci_sock.c:1314
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 17 Dec 2025 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Important


Tue, 16 Dec 2025 15:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sock: Prevent race in socket write iter and sock bind There is a potential race condition between sock bind and socket write iter. bind may free the same cmd via mgmt_pending before write iter sends the cmd, just as syzbot reported in UAF[1]. Here we use hci_dev_lock to synchronize the two, thereby avoiding the UAF mentioned in [1]. [1] syzbot reported: BUG: KASAN: slab-use-after-free in mgmt_pending_remove+0x3b/0x210 net/bluetooth/mgmt_util.c:316 Read of size 8 at addr ffff888077164818 by task syz.0.17/5989 Call Trace: mgmt_pending_remove+0x3b/0x210 net/bluetooth/mgmt_util.c:316 set_link_security+0x5c2/0x710 net/bluetooth/mgmt.c:1918 hci_mgmt_cmd+0x9c9/0xef0 net/bluetooth/hci_sock.c:1719 hci_sock_sendmsg+0x6ca/0xef0 net/bluetooth/hci_sock.c:1839 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 sock_write_iter+0x279/0x360 net/socket.c:1195 Allocated by task 5989: mgmt_pending_add+0x35/0x140 net/bluetooth/mgmt_util.c:296 set_link_security+0x557/0x710 net/bluetooth/mgmt.c:1910 hci_mgmt_cmd+0x9c9/0xef0 net/bluetooth/hci_sock.c:1719 hci_sock_sendmsg+0x6ca/0xef0 net/bluetooth/hci_sock.c:1839 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 sock_write_iter+0x279/0x360 net/socket.c:1195 Freed by task 5991: mgmt_pending_free net/bluetooth/mgmt_util.c:311 [inline] mgmt_pending_foreach+0x30d/0x380 net/bluetooth/mgmt_util.c:257 mgmt_index_removed+0x112/0x2f0 net/bluetooth/mgmt.c:9477 hci_sock_bind+0xbe9/0x1000 net/bluetooth/hci_sock.c:1314
Title Bluetooth: hci_sock: Prevent race in socket write iter and sock bind
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-12-16T15:06:22.812Z

Reserved: 2025-12-16T14:48:05.294Z

Link: CVE-2025-68305

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2025-12-16T16:16:10.030

Modified: 2025-12-16T16:16:10.030

Link: CVE-2025-68305

cve-icon Redhat

Severity : Important

Publid Date: 2025-12-16T00:00:00Z

Links: CVE-2025-68305 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.