CVE-2025-68305

Unknown Unknown - Not Provided

BaseFortify

Publication date: 2025-12-16

Last updated on: 2025-12-18

Assigner: kernel.org

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

CVSS Scores

EPSS Scores

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Meta Information

Published

2025-12-16

Last Modified

2025-12-18

Generated

2026-07-06

AI Q&A

2025-12-17

EPSS Evaluated

2026-07-05

NVD

CVE-2025-68305

EUVD

EUVD-2025-203775

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Mitigation Strategies

The vulnerability has been resolved by synchronizing the socket write iter and sock bind operations using hci_dev_lock to prevent the race condition. Immediate mitigation would involve updating the Linux kernel to a version that includes this fix.

Executive Summary

This vulnerability is a race condition in the Linux kernel's Bluetooth subsystem, specifically in the hci_sock component. It occurs between the socket bind operation and the socket write iterator, where the bind operation may free a command object just before the write iterator tries to send it. This leads to a use-after-free (UAF) condition, which can cause memory corruption or crashes. The fix involves using a lock (hci_dev_lock) to synchronize these operations and prevent the race.

Impact Analysis

The vulnerability can lead to use-after-free memory errors in the Bluetooth subsystem of the Linux kernel. This can cause system instability, crashes, or potentially allow an attacker to execute arbitrary code or cause denial of service by exploiting the race condition.

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