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Unscored CVE-2025-40308 EUVD-2025-201637GHSA-4r3x-4wj9-mxfm

Bluetooth: bcsp: receive data only if registered

Published Dec 8, 2025 · Updated May 23, 2026 · Assigned by Linux

Vendor: Linux Product: Linux Package: linux Package: linux Package: linux-allwinner-5.19 Package: linux-aws Package: linux-aws-5.0 Package: linux-aws-5.11 Package: linux-aws-5.13 Package: linux-aws-5.15 Package: linux-aws-5.19 Package: linux-aws-5.3 Package: linux-aws-5.8 Package: linux-aws-6.14 Package: linux-aws-6.17 Package: linux-aws-6.2 Package: linux-aws-6.5 Package: linux-aws-6.8 Package: linux-aws-fips Package: linux-azure Package: linux-azure-5.11 Package: linux-azure-5.13 Package: linux-azure-5.15 Package: linux-azure-5.19 Package: linux-azure-5.3 Package: linux-azure-5.8 Package: linux-azure-6.11 Package: linux-azure-6.14 Package: linux-azure-6.2 Package: linux-azure-6.5 Package: linux-azure-edge Package: linux-azure-fde Package: linux-azure-fde-5.19 Package: linux-azure-fde-6.14 Package: linux-azure-fde-6.2 Package: linux-azure-fde-6.8 Package: linux-azure-fips Package: linux-azure-nvidia-6.14 Package: linux-bluefield Package: linux-fips Package: linux-gcp Package: linux-gcp-5.11 Package: linux-gcp-5.13 Package: linux-gcp-5.15 Package: linux-gcp-5.19 Package: linux-gcp-5.3 Package: linux-gcp-5.8 Package: linux-gcp-6.11 Package: linux-gcp-6.14 Package: linux-gcp-6.17 Package: linux-gcp-6.2 Package: linux-gcp-6.5 Package: linux-gcp-6.8 Package: linux-gcp-fips Package: linux-gke Package: linux-gke-4.15 Package: linux-gke-5.15 Package: linux-gke-5.4 Package: linux-gkeop Package: linux-gkeop-5.15 Package: linux-gkeop-5.4 Package: linux-hwe Package: linux-hwe-5.11 Package: linux-hwe-5.13 Package: linux-hwe-5.15 Package: linux-hwe-5.19 Package: linux-hwe-5.8 Package: linux-hwe-6.11 Package: linux-hwe-6.14 Package: linux-hwe-6.2 Package: linux-hwe-6.5 Package: linux-hwe-6.8 Package: linux-hwe-edge Package: linux-ibm Package: linux-ibm-5.15 Package: linux-ibm-6.8 Package: linux-intel-5.13 Package: linux-intel-iot-realtime Package: linux-intel-iotg Package: linux-intel-iotg-5.15 Package: linux-kvm Package: linux-lowlatency Package: linux-lowlatency-hwe-5.15 Package: linux-lowlatency-hwe-5.19 Package: linux-lowlatency-hwe-6.11 Package: linux-lowlatency-hwe-6.2 Package: linux-lowlatency-hwe-6.5 Package: linux-lowlatency-hwe-6.8 Package: linux-nvidia Package: linux-nvidia-6.11 Package: linux-nvidia-6.17 Package: linux-nvidia-6.2 Package: linux-nvidia-6.5 Package: linux-nvidia-6.8 Package: linux-nvidia-lowlatency Package: linux-nvidia-tegra Package: linux-nvidia-tegra-5.15 Package: linux-nvidia-tegra-igx Package: linux-oem Package: linux-oem-5.10 Package: linux-oem-5.13 Package: linux-oem-5.14 Package: linux-oem-5.17 Package: linux-oem-5.6 Package: linux-oem-6.0 Package: linux-oem-6.1 Package: linux-oem-6.11 Package: linux-oem-6.14 Package: linux-oem-6.17 Package: linux-oem-6.5 Package: linux-oem-6.8 Package: linux-oracle Package: linux-oracle-5.0 Package: linux-oracle-5.11 Package: linux-oracle-5.13 Package: linux-oracle-5.15 Package: linux-oracle-5.3 Package: linux-oracle-5.8 Package: linux-oracle-6.14 Package: linux-oracle-6.17 Package: linux-oracle-6.5 Package: linux-oracle-6.8 Package: linux-raspi Package: linux-raspi-realtime Package: linux-raspi2 Package: linux-realtime Package: linux-realtime-6.14 Package: linux-realtime-6.17 Package: linux-realtime-6.8 Package: linux-riscv Package: linux-riscv-5.11 Package: linux-riscv-5.15 Package: linux-riscv-5.19 Package: linux-riscv-5.8 Package: linux-riscv-6.14 Package: linux-riscv-6.5 Package: linux-riscv-6.8 Package: linux-starfive-5.19 Package: linux-starfive-6.2 Package: linux-starfive-6.5 Package: linux-vmware Package: linux-xilinx Package: linux-xilinx-zynqmp Platform: Linux Ecosystem: Debian Ecosystem: Ubuntu

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.

Affected products

VendorProductAffectedFixed
Linux Linux 5.4.293 – < 5.4.302, 5.10.237 – < 5.10.247, 5.15.181 – < 5.15.197, 6.1.135 – < 6.1.159, 6.6.88 – < 6.6.117, 6.12.24 – < 6.12.58, 6.13.12 – < 6.14, 6.14.3 – < 6.15, 6.15 5.4.302

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 linux 6.17.8-1 —
Debian 13 linux 6.12.63-1 —
Debian 12 linux 6.1.159-1 —
Debian 11 linux 5.10.247-1 DLA-4404-1
Debian 11 linux-6.1 6.1.159-1~deb11u1 DLA-4436-1
ReleasePackageFixed inAdvisory
Ubuntu Nvidia-BlueField 24.04 LTS linux-bluefield 6.8.0-1017.21 —
Ubuntu Nvidia-BlueField 22.04 LTS linux-bluefield 5.15.0-1086.88 —
Ubuntu 25.10 linux 6.17.0-14.14 USN-8029-1
Ubuntu 25.10 linux-aws +2 6.17.0-1007.7 USN-8030-1, USN-8029-2
Ubuntu 25.10 linux-azure +1 6.17.0-1008.8 USN-8029-3, USN-8029-1
Ubuntu 25.10 linux-azure-fde No fix yet —
Ubuntu 25.10 linux-realtime 6.17.0-1006.7 USN-8029-1
Ubuntu 25.10 linux-riscv 6.17.0-14.14.1 —
Ubuntu 24.04 LTS linux 6.8.0-106.106 USN-8095-1
Ubuntu 24.04 LTS linux-aws 6.8.0-1050.53 USN-8095-1
Ubuntu 24.04 LTS linux-aws-6.17 +1 6.17.0-1007.7~24.04.1 —
Ubuntu 24.04 LTS linux-azure 6.8.0-1051.57 USN-8125-1
Ubuntu 24.04 LTS linux-azure-fde 6.8.0-1058.65 —
Ubuntu 24.04 LTS linux-gcp 6.8.0-1052.55 USN-8095-1
Ubuntu 24.04 LTS linux-gcp-6.17 6.17.0-1008.8~24.04.1 —
Ubuntu 24.04 LTS linux-gke 6.8.0-1048.53 USN-8095-1
Ubuntu 24.04 LTS linux-gkeop 6.8.0-1035.38 USN-8095-1
Ubuntu 24.04 LTS linux-ibm 6.8.0-1049.49 USN-8095-1
Ubuntu 24.04 LTS linux-lowlatency 6.8.0-106.106.1 USN-8095-1
Ubuntu 24.04 LTS linux-nvidia 6.8.0-1049.52 USN-8100-1
Ubuntu 24.04 LTS linux-nvidia-6.17 6.17.0-1008.8 —
Ubuntu 24.04 LTS linux-nvidia-lowlatency 6.8.0-1049.52.1 USN-8100-1
Ubuntu 24.04 LTS linux-oem-6.17 6.17.0-1011.11 USN-8048-1
Ubuntu 24.04 LTS linux-oracle 6.8.0-1047.48 USN-8095-1
Ubuntu 24.04 LTS linux-raspi 6.8.0-1050.54 USN-8095-5
Ubuntu 24.04 LTS linux-riscv +18 No fix yet —
Ubuntu 24.04 LTS linux-xilinx 6.8.0-1028.29 USN-8261-1
Ubuntu 22.04 LTS linux +1 5.15.0-173.183 USN-8096-1
Ubuntu 22.04 LTS linux-aws 5.15.0-1103.110 USN-8096-1
Ubuntu 22.04 LTS linux-aws-6.8 6.8.0-1050.53~22.04.1 USN-8095-4
Ubuntu 22.04 LTS linux-azure 5.15.0-1109.118 USN-8163-2
Ubuntu 22.04 LTS linux-azure-6.8 6.8.0-1051.57~22.04.1 USN-8126-1
Ubuntu 22.04 LTS linux-azure-fde 5.15.0-1109.118.1 —
Ubuntu 22.04 LTS linux-azure-fde-6.8 6.8.0-1058.65~22.04.1 —
Ubuntu 22.04 LTS linux-gcp 5.15.0-1103.112 USN-8096-1
Ubuntu 22.04 LTS linux-gcp-6.8 6.8.0-1052.55~22.04.1 USN-8095-1
Ubuntu 22.04 LTS linux-gke 5.15.0-1099.105 USN-8096-3
Ubuntu 22.04 LTS linux-gkeop 5.15.0-1086.94 USN-8096-1
Ubuntu 22.04 LTS linux-hwe-6.8 +1 6.8.0-106.106~22.04.1 USN-8095-1
Ubuntu 22.04 LTS linux-ibm +1 5.15.0-1097.100 USN-8141-1, USN-8096-1
Ubuntu 22.04 LTS linux-ibm-6.8 6.8.0-1049.49~22.04.1 USN-8095-1
Ubuntu 22.04 LTS linux-intel-iotg 5.15.0-1098.104 USN-8096-1
Ubuntu 22.04 LTS linux-kvm 5.15.0-1095.100 USN-8096-1
Ubuntu 22.04 LTS linux-lowlatency-hwe-6.8 6.8.0-106.106.1~22.04.1 USN-8095-1
Ubuntu 22.04 LTS linux-nvidia 5.15.0-1098.99 USN-8096-1
Ubuntu 22.04 LTS linux-nvidia-6.8 6.8.0-1049.52~22.04.1 USN-8100-1
Ubuntu 22.04 LTS linux-nvidia-tegra 5.15.0-1055.55 USN-8096-1
Ubuntu 22.04 LTS linux-nvidia-tegra-igx 5.15.0-1044.44 USN-8096-5
Ubuntu 22.04 LTS linux-oracle 5.15.0-1100.106 USN-8096-1
Ubuntu 22.04 LTS linux-oracle-6.8 6.8.0-1047.48~22.04.1 USN-8095-1
Ubuntu 22.04 LTS linux-riscv +32 No fix yet —
Ubuntu 22.04 LTS linux-xilinx-zynqmp 5.15.0-1067.71 USN-8096-1
Show 8 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 20.04 LTS linux-gke +28 No fix yet —
Ubuntu 18.04 LTS linux-gcp +14 No fix yet —
Ubuntu 16.04 LTS linux-hwe-edge No fix yet —
Ubuntu Pro Realtime 24.04 LTS linux-raspi-realtime 6.8.0-2040.41 USN-8095-5
Ubuntu Pro Realtime 24.04 LTS linux-realtime 6.8.1-1045.46 USN-8095-3
Ubuntu Pro Realtime 24.04 LTS linux-realtime-6.14 No fix yet —
Ubuntu Pro Realtime 24.04 LTS linux-realtime-6.17 6.17.0-1006.7~24.04.1 —
Ubuntu Pro Realtime 22.04 LTS linux-intel-iot-realtime 5.15.0-1094.96 USN-8116-1
Ubuntu Pro Realtime 22.04 LTS linux-realtime 5.15.0-1102.111 USN-8096-4
Ubuntu Pro Realtime 22.04 LTS linux-realtime-6.8 6.8.1-1045.46~22.04.1 USN-8095-3
Ubuntu Pro FIPS-updates 24.04 LTS linux-aws-fips 6.8.0-1050.53+fips1 USN-8095-2
Ubuntu Pro FIPS-updates 24.04 LTS linux-azure-fips 6.8.0-1052.58+fips1 USN-8165-1
Ubuntu Pro FIPS-updates 24.04 LTS linux-fips 6.8.0-106.106+fips1 USN-8095-2
Ubuntu Pro FIPS-updates 24.04 LTS linux-gcp-fips 6.8.0-1052.55+fips1 USN-8095-2
Ubuntu Pro FIPS-updates 22.04 LTS linux-aws-fips 5.15.0-1103.110+fips1 USN-8096-2
Ubuntu Pro FIPS-updates 22.04 LTS linux-azure-fips 5.15.0-1109.118+fips1 USN-8163-1
Ubuntu Pro FIPS-updates 22.04 LTS linux-fips 5.15.0-173.183+fips1 USN-8096-2
Ubuntu Pro FIPS-updates 22.04 LTS linux-gcp-fips 5.15.0-1103.112+fips1 USN-8096-2
Ubuntu Pro 20.04 LTS linux-aws-5.15 5.15.0-1103.110~20.04.1 USN-8096-3
Ubuntu Pro 20.04 LTS linux-azure-5.15 5.15.0-1110.119~20.04.1 USN-8243-1
Ubuntu Pro 20.04 LTS linux-gcp-5.15 5.15.0-1103.112~20.04.1 USN-8096-3
Ubuntu Pro 20.04 LTS linux-hwe-5.15 +1 5.15.0-173.183~20.04.1 USN-8096-3
Ubuntu Pro 20.04 LTS linux-ibm-5.15 5.15.0-1097.100~20.04.1 USN-8096-1
Ubuntu Pro 20.04 LTS linux-intel-iotg-5.15 5.15.0-1098.104~20.04.1 USN-8096-3
Ubuntu Pro 20.04 LTS linux-nvidia-tegra-5.15 5.15.0-1055.55~20.04.1 USN-8096-1
Ubuntu Pro 20.04 LTS linux-oracle-5.15 5.15.0-1100.106~20.04.1 USN-8096-3
Ubuntu Pro 20.04 LTS linux-riscv-5.15 5.15.0-1097.101~20.04.1 —
ReleasePackageFixed inAdvisory
SLES 15 SP7 kernel-64kb +6 6.4.0-150700.53.28.1 SUSE-SU-2026:0315-1
SLES 15 SP7 kernel-azure +2 6.4.0-150700.20.24.1 SUSE-SU-2026:0281-1
SLES 15 SP7 kernel-default-base 6.4.0-150700.53.28.1.150700.17.19.1 SUSE-SU-2026:0315-1
SLES 15 SP6 kernel-64kb +6 6.4.0-150600.23.84.1 SUSE-SU-2026:0293-1
SLES 15 SP6 kernel-default-base 6.4.0-150600.23.84.1.150600.12.38.1 SUSE-SU-2026:0293-1
SLES 12 SP5 kernel-syms +2 4.12.14-122.290.1 SUSE-SU-2026:0316-1
Show 10 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLES for SAP 16.0 kernel-64kb +8 6.12.0-160000.9.1 SUSE-SU-2026:20220-1
SLES for SAP 16.0 kernel-default-base 6.12.0-160000.9.1.160000.2.6 SUSE-SU-2026:20220-1
SLES for SAP 15 SP6 kernel-default-base 6.4.0-150600.23.84.1.150600.12.38.1 SUSE-SU-2026:0293-1
SLES for SAP 15 SP6 kernel-docs +4 6.4.0-150600.23.84.1 SUSE-SU-2026:0293-1
SLES 16.0 kernel-64kb +8 6.12.0-160000.9.1 SUSE-SU-2026:20228-1, SUSE-SU-2026:20220-1
SLES 16.0 kernel-default-base 6.12.0-160000.9.1.160000.2.6 SUSE-SU-2026:20220-1
SLE Micro 6.2 kernel-default-base 6.12.0-160000.9.1.160000.2.6 SUSE-SU-2026:20207-1
SLE Micro 6.2 kernel-rt +5 6.12.0-160000.9.1 SUSE-SU-2026:20564-1, SUSE-SU-2026:20207-1
SLE Micro 6.1 kernel-default-base 6.4.0-39.1.21.16 SUSE-SU-2026:20498-1
SLE Micro 6.1 kernel-rt +1 6.4.0-40.1 SUSE-SU-2026:20876-1
SLE Micro 6.1 kernel-source +2 6.4.0-39.1 SUSE-SU-2026:20498-1
SLE Micro 6.0 kernel-default-base 6.4.0-39.1.21.16 SUSE-SU-2026:20477-1
SLE Micro 6.0 kernel-rt +1 6.4.0-40.1 SUSE-SU-2026:20845-1
SLE Micro 6.0 kernel-source +2 6.4.0-39.1 SUSE-SU-2026:20477-1
SLE Live Patching 15 SP7 kernel-default 6.4.0-150700.53.28.1 SUSE-SU-2026:0315-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7-RT_Update_8 1-150700.1.3.1 SUSE-SU-2026:0278-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7_Update_8 1-150700.15.3.1 SUSE-SU-2026:0315-1
SLE Live Patching 15 SP6 kernel-default 6.4.0-150600.23.84.1 SUSE-SU-2026:0293-1
SLE Live Patching 15 SP6 kernel-livepatch-SLE15-SP6_Update_19 1-150600.13.3.1 SUSE-SU-2026:0293-1
SLE Live Patching 12 SP5 kernel-default 4.12.14-122.290.1 SUSE-SU-2026:0316-1
SLE Live Patching 12 SP5 kgraft-patch-SLE12-SP5_Update_76 1-8.7.1 SUSE-SU-2026:0316-1
SUSE Real Time Module 15 SP7 kernel-rt +2 6.4.0-150700.7.28.1 SUSE-SU-2026:0278-1
ReleasePackageFixed inAdvisory
openSUSE Leap 16.0 kernel-default-base 6.12.0-160000.9.1.160000.2.6 openSUSE-SU-2026:20145-1
openSUSE Leap 16.0 kernel-rt +11 6.12.0-160000.9.1 openSUSE-SU-2026:20145-1
openSUSE Leap 15.6 dtb-aarch64 +10 6.4.0-150600.23.84.1 SUSE-SU-2026:0293-1
openSUSE Leap 15.6 kernel-default-base 6.4.0-150600.23.84.1.150600.12.38.1 SUSE-SU-2026:0293-1

Oracle Linux

ReleasePackageFixed inAdvisory
Oracle Linux 9 kernel-uek +34 6.12.0-107.59.3.2.el10uek ELSA-2026-50006
Oracle Linux 8 bpftool +18 5.15.0-317.197.5.1.el9uek ELSA-2026-50113
Oracle Linux 7 kernel-uek +6 5.4.17-2136.352.5.el8uek ELSA-2026-50100
Oracle Linux 7 kernel-uek-tools 5.4.17-2136.352.5.el7uek ELSA-2026-50100

Advisories 45

References