CVE-2025-40308

Bluetooth: bcsp: receive data only if registered

State: Published
Severity: Not scored
Published: Dec 8, 2025
Updated: May 23, 2026
Reserved: Apr 16, 2025

Description

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

Bluetooth: bcsp: receive data only if registered

Currently, bcsp_recv() can be called even when the BCSP protocol has not been registered. This leads to a NULL pointer dereference, as shown in the following stack trace:

KASAN: null-ptr-deref in range [0x0000000000000108-0x000000000000010f] RIP: 0010:bcsp_recv+0x13d/0x1740 drivers/bluetooth/hci_bcsp.c:590 Call Trace: <TASK> hci_uart_tty_receive+0x194/0x220 drivers/bluetooth/hci_ldisc.c:627 tiocsti+0x23c/0x2c0 drivers/tty/tty_io.c:2290 tty_ioctl+0x626/0xde0 drivers/tty/tty_io.c:2706 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f

To prevent this, ensure that the HCI_UART_REGISTERED flag is set before processing received data. If the protocol is not registered, return -EUNATCH.

Scores

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	48effdb7a798232db945503cf3f51e0be8070cea to before 39a7d40314b6288cfa2d13269275e9247a7a055aAffected 45fa7bd82c6178f4fec0ab94891144a043ec5fe8 to before 164586725b47f9d61912e6bf17dbaffeff11710bAffected d71a57a34ab6bbc95dc461158403c02e8ff3f912 to before b65ca9708bfbf47d8b7bd44b7c574bd16798e9c9Affected 9cf7dccaa7f4c56d2089700e5cb11f85a8d5f6cf to before 8b892dbef3887dbe9afdc7176d1a5fd90e1636aaAffected 806464634e7fc6b523160defeeddb1ade2a72f81 to before 799cd62cbcc3f12ee04b33ef390ff7d41c37d671Affected 6b7a32fa9bacdebd98c18b2a56994116995ee643 to before b420a4c7f915fc1c94ad1f6ca740acc046d94334Affected 366ceff495f902182d42b6f41525c2474caf3f9a to before 55c1519fca830f59a10bbf9aa8209c87b06cf7bcAffected 366ceff495f902182d42b6f41525c2474caf3f9a to before ca94b2b036c22556c3a66f1b80f490882deef7a6Affected 15543b7bbe7b5f744fdbb44f75b14f81a0117813Affected a4b89a45b12b69bc82c8137346b150a118e02c26Affected 5.4.293 to before 5.4.302Affected 5.10.237 to before 5.10.247Affected 5.15.181 to before 5.15.197Affected 6.1.135 to before 6.1.159Affected 6.6.88 to before 6.6.117Affected 6.12.24 to before 6.12.58Affected 6.13.12 to before 6.14Affected 6.14.3 to before 6.15Affected
LinuxLinux	6.15Affected before 6.15Not affected 5.4.302 through 5.4.Not affected 5.10.247 through 5.10.Not affected 5.15.197 through 5.15.Not affected 6.1.159 through 6.1.Not affected 6.6.117 through 6.6.Not affected 6.12.58 through 6.12.Not affected 6.17.8 through 6.17.*Not affected 6.18 and laterNot affected

Product

Versions

LinuxLinux

48effdb7a798232db945503cf3f51e0be8070cea to before 39a7d40314b6288cfa2d13269275e9247a7a055aAffected
45fa7bd82c6178f4fec0ab94891144a043ec5fe8 to before 164586725b47f9d61912e6bf17dbaffeff11710bAffected
d71a57a34ab6bbc95dc461158403c02e8ff3f912 to before b65ca9708bfbf47d8b7bd44b7c574bd16798e9c9Affected
9cf7dccaa7f4c56d2089700e5cb11f85a8d5f6cf to before 8b892dbef3887dbe9afdc7176d1a5fd90e1636aaAffected
806464634e7fc6b523160defeeddb1ade2a72f81 to before 799cd62cbcc3f12ee04b33ef390ff7d41c37d671Affected
6b7a32fa9bacdebd98c18b2a56994116995ee643 to before b420a4c7f915fc1c94ad1f6ca740acc046d94334Affected
366ceff495f902182d42b6f41525c2474caf3f9a to before 55c1519fca830f59a10bbf9aa8209c87b06cf7bcAffected
366ceff495f902182d42b6f41525c2474caf3f9a to before ca94b2b036c22556c3a66f1b80f490882deef7a6Affected
15543b7bbe7b5f744fdbb44f75b14f81a0117813Affected
a4b89a45b12b69bc82c8137346b150a118e02c26Affected
5.4.293 to before 5.4.302Affected
5.10.237 to before 5.10.247Affected
5.15.181 to before 5.15.197Affected
6.1.135 to before 6.1.159Affected
6.6.88 to before 6.6.117Affected
6.12.24 to before 6.12.58Affected
6.13.12 to before 6.14Affected
6.14.3 to before 6.15Affected

LinuxLinux

6.15Affected
before 6.15Not affected
5.4.302 through 5.4.*Not affected
5.10.247 through 5.10.*Not affected
5.15.197 through 5.15.*Not affected
6.1.159 through 6.1.*Not affected
6.6.117 through 6.6.*Not affected
6.12.58 through 6.12.*Not affected
6.17.8 through 6.17.*Not affected
6.18 and laterNot affected

References

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