CVE-2025-68305: Bluetooth: hci_sock: Prevent race in socket write iter and sock bind

Severity: unknown
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-12-16 · updated 2026-10-14

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

Affected products

Linux kernel: from 6.6.94 before 6.6.119; from 6.12.34 before 6.12.61; from 6.15.3 before 6.16; 6.16 — fixed in 6.12.61, 6.16, 6.18, 6.6.119

How to fix

Upgrade to a fixed version: Linux kernel 6.12.61, 6.16, 6.18, 6.6.119. Check the vendor advisory for mitigations.

References

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