CVE-2024-26959
NoneCVSS
—
EPSS
0.2%
Published
May 1, 2024
CISA due date
—
Cloudanix analysis
A bug in Linux Bluetooth handling for certain hardware could make the whole computer crash when Bluetooth is turned off.
- Exploitation
- Local Privilege
- Attacker needs
- Local User
- Complexity
- High
- Impact
- Denial Of Service
- Component
- OS kernel
- Class
- Race Condition
- Remediation
- Upgrade
- Effort
- Medium
- Patch risk
- Low
What it actually does
Race condition in btnxpuart_close() triggers scheduling while atomic by failing to properly purge the transmit queue and free the receive skb before calling into uart_update_mctrl and related tty layer functions from a workqueue context.
Why it matters to the business
Unexpected kernel crashes or system instability on Linux devices using the affected Bluetooth UART driver, potentially disrupting wireless connectivity and requiring reboots in embedded or server environments.
How an attack unfolds
An attacker triggers repeated open/close cycles on the Bluetooth HCI device (for example via userspace tools or malicious processes) under concurrent power-off workqueue activity, hitting the atomic scheduling bug before the upstream fix in commit d4e2365b07f1ae1f811a915b514caef5b2d6581e.
How to fix it
Upgrade the Linux kernel to commit d4e2365b07f1ae1f811a915b514caef5b2d6581e or later stable releases that include the fix for btnxpuart_close; rebuild and deploy the updated kernel image on affected systems.
How to confirm the fix worked
Confirm the running kernel contains commit d4e2365b07f1ae1f811a915b514caef5b2d6581e via git log or uname; attempt Bluetooth device open/close cycles while monitoring dmesg for absence of the scheduling-while-atomic BUG.
Typical attack path
- Obtain local execution or userspace access on the target Linux system
- Interact with the btnxpuart Bluetooth device to initiate HCI power-off or close operations
- Race the close path against workqueue hci_power_off to trigger the atomic scheduling violation
- Cause kernel BUG/panic and potential denial of service
How to detect it
Review kernel logs (dmesg/journalctl) for 'BUG: scheduling while atomic' traces referencing btnxpuart_close, hci_power_off, or uart_update_mctrl around Bluetooth shutdown events.
What your security team should do
- Prioritize kernel upgrades on all systems exposing the btnxpuart driver
- Monitor vendor advisories for backported fixes in distribution kernels
- Restrict unprivileged access to Bluetooth device nodes until patched
The record
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: btnxpuart: Fix btnxpuart_close Fix scheduling while atomic BUG in btnxpuart_close(), properly purge the transmit queue and free the receive skb. [ 10.973809] BUG: scheduling while atomic: kworker/u9:0/80/0x00000002 ... [ 10.980740] CPU: 3 PID: 80 Comm: kworker/u9:0 Not tainted 6.8.0-rc7-0.0.0-devel-00005-g61fdfceacf09 #1 [ 10.980751] Hardware name: Toradex Verdin AM62 WB on Dahlia Board (DT) [ 10.980760] Workqueue: hci0 hci_power_off [bluetooth] [ 10.981169] Call trace: ... [ 10.981363] uart_update_mctrl+0x58/0x78 [ 10.981373] uart_dtr_rts+0x104/0x114 [ 10.981381] tty_port_shutdown+0xd4/0xdc [ 10.981396] tty_port_close+0x40/0xbc [ 10.981407] uart_close+0x34/0x9c [ 10.981414] ttyport_close+0x50/0x94 [ 10.981430] serdev_device_close+0x40/0x50 [ 10.981442] btnxpuart_close+0x24/0x98 [btnxpuart] [ 10.981469] hci_dev_close_sync+0x2d8/0x718 [bluetooth] [ 10.981728] hci_dev_do_close+0x2c/0x70 [bluetooth] [ 10.981862] hci_power_off+0x20/0x64 [bluetooth]
Affected packages
| Ecosystem | Package | Introduced | Fixed |
|---|---|---|---|
| Debian:13 | linux | 0 | 6.7.12-1 |
| Debian:14 | linux | 0 | 6.7.12-1 |
| Linux | Kernel | 6.4.0 | 6.6.24 |
| Ubuntu:14.04:LTS | linux | 0 | 3.11.0-12.19 |
| Ubuntu:14.04:LTS | linux-aws | 0 | 4.4.0-1002.2 |
| Ubuntu:14.04:LTS | linux-azure | 0 | 4.15.0-1023.24~14.04.1 |
| Ubuntu:14.04:LTS | linux-lts-xenial | 0 | 4.4.0-13.29~14.04.1 |
| Ubuntu:16.04:LTS | linux | 0 | 4.4.0-2.16 |
| Ubuntu:16.04:LTS | linux-aws | 0 | 4.4.0-1001.10 |
| Ubuntu:16.04:LTS | linux-aws-hwe | 0 | 4.15.0-1030.31~16.04.1 |
| Ubuntu:16.04:LTS | linux-azure | 0 | 4.11.0-1009.9 |
| Ubuntu:16.04:LTS | linux-gcp | 0 | 4.10.0-1004.4 |
| Ubuntu:16.04:LTS | linux-hwe | 0 | 4.8.0-39.42~16.04.1 |
| Ubuntu:16.04:LTS | linux-hwe-edge | 0 | No fix |
| Ubuntu:16.04:LTS | linux-kvm | 0 | 4.4.0-1004.9 |
| Ubuntu:16.04:LTS | linux-oracle | 0 | 4.15.0-1007.9~16.04.1 |
| Ubuntu:18.04:LTS | linux | 0 | 4.13.0-16.19 |
| Ubuntu:18.04:LTS | linux-aws | 0 | 4.15.0-1001.1 |
| Ubuntu:18.04:LTS | linux-aws-5.0 | 0 | No fix |
| Ubuntu:18.04:LTS | linux-aws-5.3 | 0 | No fix |
| Ubuntu:18.04:LTS | linux-aws-5.4 | 0 | 5.4.0-1018.18~18.04.1 |
| Ubuntu:18.04:LTS | linux-azure | 0 | No fix |
| Ubuntu:18.04:LTS | linux-azure-4.15 | 0 | 4.15.0-1082.92 |
| Ubuntu:18.04:LTS | linux-azure-5.3 | 0 | No fix |
| Ubuntu:18.04:LTS | linux-azure-5.4 | 0 | 5.4.0-1020.20~18.04.1 |
| Ubuntu:18.04:LTS | linux-azure-edge | 0 | No fix |
| Ubuntu:18.04:LTS | linux-gcp | 0 | No fix |
| Ubuntu:18.04:LTS | linux-gcp-4.15 | 0 | 4.15.0-1071.81 |
| Ubuntu:18.04:LTS | linux-gcp-5.3 | 0 | No fix |
| Ubuntu:18.04:LTS | linux-gcp-5.4 | 0 | 5.4.0-1019.19~18.04.2 |
| Ubuntu:18.04:LTS | linux-gke-4.15 | 0 | No fix |
| Ubuntu:18.04:LTS | linux-gke-5.4 | 0 | No fix |
| Ubuntu:18.04:LTS | linux-gkeop-5.4 | 0 | No fix |
| Ubuntu:18.04:LTS | linux-hwe | 0 | No fix |
| Ubuntu:18.04:LTS | linux-hwe-5.4 | 0 | 5.4.0-37.41~18.04.1 |
| Ubuntu:18.04:LTS | linux-hwe-edge | 0 | 5.0.0-15.16~18.04.1 |
| Ubuntu:18.04:LTS | linux-ibm-5.4 | 0 | 5.4.0-1010.11~18.04.2 |
| Ubuntu:18.04:LTS | linux-kvm | 0 | 4.15.0-1002.2 |
| Ubuntu:18.04:LTS | linux-oem | 0 | No fix |
| Ubuntu:18.04:LTS | linux-oracle | 0 | 4.15.0-1007.9 |
| Ubuntu:18.04:LTS | linux-oracle-5.0 | 0 | No fix |
| Ubuntu:18.04:LTS | linux-oracle-5.3 | 0 | No fix |
| Ubuntu:18.04:LTS | linux-oracle-5.4 | 0 | 5.4.0-1019.19~18.04.1 |
| Ubuntu:18.04:LTS | linux-raspi-5.4 | 0 | 5.4.0-1013.13~18.04.1 |
| Ubuntu:20.04:LTS | linux | 0 | 5.4.0-9.12 |
| Ubuntu:20.04:LTS | linux-aws | 0 | 5.4.0-1005.5 |
| Ubuntu:20.04:LTS | linux-aws-5.11 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-aws-5.13 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-aws-5.15 | 0 | 5.15.0-1014.18~20.04.1 |
| Ubuntu:20.04:LTS | linux-aws-5.8 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-azure | 0 | 5.4.0-1006.6 |
| Ubuntu:20.04:LTS | linux-azure-5.11 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-azure-5.13 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-azure-5.15 | 0 | 5.15.0-1007.8~20.04.1 |
| Ubuntu:20.04:LTS | linux-azure-5.8 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-azure-fde | 0 | No fix |
| Ubuntu:20.04:LTS | linux-azure-fde-5.15 | 0 | 5.15.0-1019.24~20.04.1.1 |
| Ubuntu:20.04:LTS | linux-bluefield | 0 | 5.4.0-1007.10 |
| Ubuntu:20.04:LTS | linux-gcp | 0 | 5.4.0-1005.5 |
| Ubuntu:20.04:LTS | linux-gcp-5.11 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-gcp-5.13 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-gcp-5.15 | 0 | 5.15.0-1006.9~20.04.1 |
| Ubuntu:20.04:LTS | linux-gcp-5.8 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-gke | 0 | No fix |
| Ubuntu:20.04:LTS | linux-gke-5.15 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-gkeop | 0 | 5.4.0-1008.9 |
| Ubuntu:20.04:LTS | linux-gkeop-5.15 | 0 | 5.15.0-1003.5~20.04.2 |
| Ubuntu:20.04:LTS | linux-hwe-5.11 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-hwe-5.13 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-hwe-5.15 | 0 | 5.15.0-33.34~20.04.1 |
| Ubuntu:20.04:LTS | linux-hwe-5.8 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-ibm | 0 | 5.4.0-1003.4 |
| Ubuntu:20.04:LTS | linux-ibm-5.15 | 0 | 5.15.0-1033.36~20.04.1 |
| Ubuntu:20.04:LTS | linux-intel-5.13 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-intel-iotg-5.15 | 0 | 5.15.0-1003.5~20.04.1 |
| Ubuntu:20.04:LTS | linux-iot | 0 | 5.4.0-1001.3 |
| Ubuntu:20.04:LTS | linux-kvm | 0 | 5.4.0-1004.4 |
| Ubuntu:20.04:LTS | linux-lowlatency-hwe-5.15 | 0 | 5.15.0-33.34~20.04.1 |
| Ubuntu:20.04:LTS | linux-oem-5.10 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-oem-5.13 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-oem-5.14 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-oem-5.6 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-oracle | 0 | 5.4.0-1005.5 |
| Ubuntu:20.04:LTS | linux-oracle-5.11 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-oracle-5.13 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-oracle-5.15 | 0 | 5.15.0-1007.9~20.04.1 |
| Ubuntu:20.04:LTS | linux-oracle-5.8 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-raspi | 0 | 5.4.0-1007.7 |
| Ubuntu:20.04:LTS | linux-raspi2 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-riscv | 0 | No fix |
| Ubuntu:20.04:LTS | linux-riscv-5.11 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-riscv-5.15 | 0 | 5.15.0-1015.17~20.04.1 |
| Ubuntu:20.04:LTS | linux-riscv-5.8 | 0 | No fix |
| Ubuntu:20.04:LTS | linux-xilinx-zynqmp | 0 | 5.4.0-1020.24 |
| Ubuntu:22.04:LTS | linux | 0 | 5.13.0-19.19 |
| Ubuntu:22.04:LTS | linux-allwinner-5.19 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-aws | 0 | 5.13.0-1005.6 |
| Ubuntu:22.04:LTS | linux-aws-5.19 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-aws-6.2 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-aws-6.5 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-aws-6.8 | 0 | 6.8.0-1009.9~22.04.2 |
| Ubuntu:22.04:LTS | linux-azure | 0 | 5.13.0-1006.7 |
| Ubuntu:22.04:LTS | linux-azure-5.19 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-azure-6.2 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-azure-6.5 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-azure-6.8 | 0 | 6.8.0-1008.8~22.04.1 |
| Ubuntu:22.04:LTS | linux-azure-fde | 0 | 5.15.0-1019.24.1 |
| Ubuntu:22.04:LTS | linux-azure-fde-5.19 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-azure-fde-6.2 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-gcp | 0 | 5.13.0-1005.6 |
| Ubuntu:22.04:LTS | linux-gcp-5.19 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-gcp-6.2 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-gcp-6.5 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-gcp-6.8 | 0 | 6.8.0-1010.11~22.04.1 |
| Ubuntu:22.04:LTS | linux-gke | 0 | 5.15.0-1002.2 |
| Ubuntu:22.04:LTS | linux-gkeop | 0 | 5.15.0-1001.2 |
| Ubuntu:22.04:LTS | linux-hwe-5.19 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-hwe-6.2 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-hwe-6.5 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-hwe-6.8 | 0 | 6.8.0-38.38~22.04.1 |
| Ubuntu:22.04:LTS | linux-ibm | 0 | 5.15.0-1002.2 |
| Ubuntu:22.04:LTS | linux-intel-iot-realtime | 0 | No fix |
| Ubuntu:22.04:LTS | linux-intel-iot-realtime | 0 | 5.15.0-1021.26 |
| Ubuntu:22.04:LTS | linux-intel-iotg | 0 | 5.15.0-1004.6 |
| Ubuntu:22.04:LTS | linux-kvm | 0 | 5.13.0-1004.4 |
| Ubuntu:22.04:LTS | linux-lowlatency | 0 | 5.15.0-22.22 |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-5.19 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-6.2 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-6.5 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-6.8 | 0 | 6.8.0-38.38.1~22.04.2 |
| Ubuntu:22.04:LTS | linux-nvidia | 0 | 5.15.0-1005.5 |
| Ubuntu:22.04:LTS | linux-nvidia-6.2 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-nvidia-6.5 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-nvidia-6.8 | 0 | 6.8.0-1008.8~22.04.1 |
| Ubuntu:22.04:LTS | linux-oem-5.17 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-oem-6.0 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-oem-6.1 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-oem-6.5 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-oracle | 0 | 5.13.0-1008.10 |
| Ubuntu:22.04:LTS | linux-oracle-6.5 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-oracle-6.8 | 0 | 6.8.0-1006.6~22.04.3 |
| Ubuntu:22.04:LTS | linux-raspi | 0 | 5.13.0-1008.9 |
| Ubuntu:22.04:LTS | linux-realtime | 0 | No fix |
| Ubuntu:22.04:LTS | linux-riscv | 0 | No fix |
| Ubuntu:22.04:LTS | linux-riscv-5.19 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-riscv-6.5 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-riscv-6.8 | 0 | 6.8.0-38.38.1~22.04.1 |
| Ubuntu:22.04:LTS | linux-starfive-5.19 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-starfive-6.2 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-starfive-6.5 | 0 | No fix |
| Ubuntu:22.04:LTS | linux-xilinx-zynqmp | 0 | 5.15.0-1022.26 |
| Ubuntu:22.04:LTS:for:NVIDIA:BlueField | linux-bluefield | 0 | 5.15.0-1011.13 |
| Ubuntu:24.04:LTS | linux | 0 | 6.8.0-35.35 |
| Ubuntu:24.04:LTS | linux-aws | 0 | 6.8.0-1009.9 |
| Ubuntu:24.04:LTS | linux-azure | 0 | 6.8.0-1008.8 |
| Ubuntu:24.04:LTS | linux-gcp | 0 | 6.8.0-1008.9 |
| Ubuntu:24.04:LTS | linux-gke | 0 | 6.8.0-1004.7 |
| Ubuntu:24.04:LTS | linux-gkeop | 0 | 6.8.0-1001.3 |
| Ubuntu:24.04:LTS | linux-ibm | 0 | 6.8.0-1006.6 |
| Ubuntu:24.04:LTS | linux-intel | 0 | 6.8.0-1005.12 |
| Ubuntu:24.04:LTS | linux-lowlatency | 0 | 6.8.0-35.35.1 |
| Ubuntu:24.04:LTS | linux-nvidia | 0 | 6.8.0-1007.7 |
| Ubuntu:24.04:LTS | linux-nvidia-lowlatency | 0 | 6.8.0-1009.9.1 |
| Ubuntu:24.04:LTS | linux-oem-6.11 | 0 | 6.11.0-1007.7 |
| Ubuntu:24.04:LTS | linux-oem-6.8 | 0 | 6.8.0-1006.6 |
| Ubuntu:24.04:LTS | linux-oracle | 0 | 6.8.0-1006.6 |
| Ubuntu:24.04:LTS | linux-raspi | 0 | 6.8.0-1005.5 |
| Ubuntu:24.04:LTS | linux-raspi-realtime | 0 | No fix |
| Ubuntu:24.04:LTS | linux-realtime | 0 | No fix |
| Ubuntu:24.04:LTS | linux-riscv | 0 | 6.8.0-35.35.1 |
| Ubuntu:24.10 | linux | 0 | 6.11.0-7.7 |
| Ubuntu:24.10 | linux-aws | 0 | 6.11.0-1002.2 |
| Ubuntu:24.10 | linux-azure | 0 | 6.11.0-1003.3 |
| Ubuntu:24.10 | linux-gcp | 0 | 6.11.0-1001.1 |
| Ubuntu:24.10 | linux-lowlatency | 0 | 6.11.0-1002.2 |
| Ubuntu:24.10 | linux-oracle | 0 | 6.11.0-1004.4 |
| Ubuntu:24.10 | linux-raspi | 0 | 6.11.0-1003.3 |
| Ubuntu:24.10 | linux-realtime | 0 | 6.11.0-1001.1 |
| Ubuntu:24.10 | linux-riscv | 0 | 6.11.0-8.8.1 |
| Ubuntu:Pro:16.04:LTS | linux-hwe-edge | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-aws-5.0 | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-aws-5.3 | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-azure | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-azure-5.3 | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-azure-edge | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-gcp | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-gcp-5.3 | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-gke-4.15 | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-gke-5.4 | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-gkeop-5.4 | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-hwe | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-hwe-edge | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-oem | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-oracle-5.0 | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-oracle-5.3 | 0 | No fix |
| Ubuntu:Pro:20.04:LTS | linux-aws-5.11 | 0 | No fix |
| Ubuntu:Pro:20.04:LTS | linux-aws-5.13 | 0 | No fix |
| Ubuntu:Pro:20.04:LTS | linux-aws-5.8 | 0 | No fix |
| Ubuntu:Pro:20.04:LTS | linux-azure-5.11 | 0 | No fix |
| Ubuntu:Pro:20.04:LTS | linux-azure-5.13 | 0 | No fix |
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