UBUNTU-CVE-2025-68758: Null Pointer Dereference
In the Linux kernel, the following vulnerability has been resolved: backlight: led-bl: Add devlink to supplier LEDs LED Backlight is a consumer of one or multiple LED class devices, but devlink is currently unable to create correct supplier-producer links when the supplier is a class device. It creates instead a link where the supplier is the parent of the expected device. One consequence is that removal order is not correctly enforced. Issues happen for example with the following sections in a device tree overlay: // An LED driver chip pca9632@62 { compatible = "nxp,pca9632"; reg = <0x62>; // ... addonledpwm: led-pwm@3 { reg = <3>; label = "addon:led:pwm"; }; }; backlight-addon { compatible = "led-backlight"; leds = <&addonledpwm>; brightness-levels = <255>; default-brightness-level = <255>; }; In this example, the devlink should be created between the backlight-addon (consumer) and the pca9632@62 (supplier). Instead it is created between the backlight-addon (consumer) and the parent of the pca9632@62, which is typically the I2C bus adapter. On removal of the above overlay, the LED driver can be removed before the backlight device, resulting in: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010 ... Call trace: ledput+0xe0/0x140 devmledrelease+0x6c/0x98 Another way to reproduce the bug without any device tree overlays is unbinding the LED class device (pca9632@62) before unbinding the consumer (backlight-addon): echo 11-0062 >/sys/bus/i2c/drivers/leds-pca963x/unbind echo ...backlight-dock >/sys/bus/platform/drivers/led-backlight/unbind Fix by adding a devlink between the consuming led-backlight device and the supplying LED device, as other drivers and subsystems do as well.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-aws-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1103.110~20.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1110.119~20.04.1 - Upgrade
Upgrade
ubuntu/linux-gcp-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1103.112~20.04.1 - Upgrade
Upgrade
ubuntu/linux-hwe-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-173.183~20.04.1 - Upgrade
Upgrade
ubuntu/linux-ibm-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1097.100~20.04.1 - Upgrade
Upgrade
ubuntu/linux-intel-iotg-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1098.104~20.04.1 - Upgrade
Upgrade
ubuntu/linux-lowlatency-hwe-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-173.183~20.04.1 - Upgrade
Upgrade
ubuntu/linux-nvidia-tegra-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1055.55~20.04.1 - Upgrade
Upgrade
ubuntu/linux-oracle-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1100.106~20.04.1 - Upgrade
Upgrade
ubuntu/linux-riscv-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1097.101~20.04.1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 5.15.0-173.183 - Upgrade
Upgrade
ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 5.15.0-1103.110 - Upgrade
Upgrade
ubuntu/linux-aws-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1052.55~22.04.1 - Upgrade
Upgrade
ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 5.15.0-1109.118 - Upgrade
Upgrade
ubuntu/linux-azure-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1059.65~22.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 5.15.0-1109.118.1 - Upgrade
Upgrade
ubuntu/linux-azure-fde-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1058.65~22.04.1 - Upgrade
Upgrade
ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 5.15.0-1103.112 - Upgrade
Upgrade
ubuntu/linux-gcp-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1054.57~22.04.1 - Upgrade
Upgrade
ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 5.15.0-1099.105 - Upgrade
Upgrade
ubuntu/linux-gkeopto a version that resolves this vulnerability.Fixed in 5.15.0-1086.94 - Upgrade
Upgrade
ubuntu/linux-hwe-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-110.110~22.04.1 - Upgrade
Upgrade
ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 5.15.0-1097.100 - Upgrade
Upgrade
ubuntu/linux-ibm-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1051.51~22.04.1 - Upgrade
Upgrade
ubuntu/linux-intel-iotgto a version that resolves this vulnerability.Fixed in 5.15.0-1098.104 - Upgrade
Upgrade
ubuntu/linux-kvmto a version that resolves this vulnerability.Fixed in 5.15.0-1095.100 - Upgrade
Upgrade
ubuntu/linux-lowlatencyto a version that resolves this vulnerability.Fixed in 5.15.0-173.183 - Upgrade
Upgrade
ubuntu/linux-lowlatency-hwe-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-110.110.1~22.04.1 - Upgrade
Upgrade
ubuntu/linux-nvidiato a version that resolves this vulnerability.Fixed in 5.15.0-1098.99 - Upgrade
Upgrade
ubuntu/linux-nvidia-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1051.54~22.04.1 - Upgrade
Upgrade
ubuntu/linux-nvidia-tegrato a version that resolves this vulnerability.Fixed in 5.15.0-1055.55 - Upgrade
Upgrade
ubuntu/linux-nvidia-tegra-igxto a version that resolves this vulnerability.Fixed in 5.15.0-1044.44 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 5.15.0-1100.106 - Upgrade
Upgrade
ubuntu/linux-oracle-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1049.50~22.04.1 - Upgrade
Upgrade
ubuntu/linux-raspito a version that resolves this vulnerability.Fixed in 5.15.0-1097.100 - Upgrade
Upgrade
ubuntu/linux-riscv-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-110.110~22.04.1 - Upgrade
Upgrade
ubuntu/linux-xilinx-zynqmpto a version that resolves this vulnerability.Fixed in 5.15.0-1067.71 - Upgrade
Upgrade
ubuntu/linux-bluefieldto a version that resolves this vulnerability.Fixed in 5.15.0-1086.88 - Upgrade
Upgrade
ubuntu/linux-intel-iot-realtimeto a version that resolves this vulnerability.Fixed in 5.15.0-1094.96 - Upgrade
Upgrade
ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 5.15.0-1102.111 - Upgrade
Upgrade
ubuntu/linux-realtime-6.8to a version that resolves this vulnerability.Fixed in 6.8.1-1047.48~22.04.1 - Upgrade
Upgrade
ubuntu/linux-aws-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1103.110+fips1 - Upgrade
Upgrade
ubuntu/linux-azure-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1109.118+fips1 - Upgrade
Upgrade
ubuntu/linux-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-173.183+fips1 - Upgrade
Upgrade
ubuntu/linux-gcp-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1103.112+fips1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 6.8.0-110.110 - Upgrade
Upgrade
ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 6.8.0-1052.55 - Upgrade
Upgrade
ubuntu/linux-aws-6.17to a version that resolves this vulnerability.Fixed in 6.17.0-1009.9~24.04.2 - Upgrade
Upgrade
ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 6.8.0-1054.60 - Upgrade
Upgrade
ubuntu/linux-azure-6.17to a version that resolves this vulnerability.Fixed in 6.17.0-1010.10~24.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 6.8.0-1058.65 - Upgrade
Upgrade
ubuntu/linux-azure-nvidiato a version that resolves this vulnerability.Fixed in 6.8.0-1039.42 - Upgrade
Upgrade
ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 6.8.0-1054.57 - Upgrade
Upgrade
ubuntu/linux-gcp-6.17to a version that resolves this vulnerability.Fixed in 6.17.0-1009.9~24.04.3 - Upgrade
Upgrade
ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 6.8.0-1050.56 - Upgrade
Upgrade
ubuntu/linux-gkeopto a version that resolves this vulnerability.Fixed in 6.8.0-1037.40 - Upgrade
Upgrade
ubuntu/linux-hwe-6.17to a version that resolves this vulnerability.Fixed in 6.17.0-19.19~24.04.2 - Upgrade
Upgrade
ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 6.8.0-1051.51 - Upgrade
Upgrade
ubuntu/linux-lowlatencyto a version that resolves this vulnerability.Fixed in 6.8.0-110.110.1 - Upgrade
Upgrade
ubuntu/linux-nvidiato a version that resolves this vulnerability.Fixed in 6.8.0-1051.54 - Upgrade
Upgrade
ubuntu/linux-nvidia-6.17to a version that resolves this vulnerability.Fixed in 6.17.0-1018.18 - Upgrade
Upgrade
ubuntu/linux-nvidia-lowlatencyto a version that resolves this vulnerability.Fixed in 6.8.0-1051.54.1 - Upgrade
Upgrade
ubuntu/linux-nvidia-tegrato a version that resolves this vulnerability.Fixed in 6.8.0-1022.22 - Upgrade
Upgrade
ubuntu/linux-oem-6.17to a version that resolves this vulnerability.Fixed in 6.17.0-1017.17 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 6.8.0-1049.50 - Upgrade
Upgrade
ubuntu/linux-oracle-6.17to a version that resolves this vulnerability.Fixed in 6.17.0-1009.9~24.04.1 - Upgrade
Upgrade
ubuntu/linux-raspito a version that resolves this vulnerability.Fixed in 6.8.0-1052.56 - Upgrade
Upgrade
ubuntu/linux-riscv-6.17to a version that resolves this vulnerability.Fixed in 6.17.0-19.19.1~24.04.1 - Upgrade
Upgrade
ubuntu/linux-xilinxto a version that resolves this vulnerability.Fixed in 6.8.0-1028.29 - Upgrade
Upgrade
ubuntu/linux-bluefieldto a version that resolves this vulnerability.Fixed in 6.8.0-1017.21 - Upgrade
Upgrade
ubuntu/linux-raspi-realtimeto a version that resolves this vulnerability.Fixed in 6.8.0-2042.43 - Upgrade
Upgrade
ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 6.8.1-1047.48 - Upgrade
Upgrade
ubuntu/linux-realtime-6.17to a version that resolves this vulnerability.Fixed in 6.17.0-1008.9~24.04.1 - Upgrade
Upgrade
ubuntu/linux-aws-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1052.55+fips1 - Upgrade
Upgrade
ubuntu/linux-azure-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1053.59+fips1 - Upgrade
Upgrade
ubuntu/linux-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-110.110+fips2 - Upgrade
Upgrade
ubuntu/linux-gcp-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1054.57+fips1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 6.17.0-19.19 - Upgrade
Upgrade
ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 6.17.0-1009.9 - Upgrade
Upgrade
ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 6.17.0-1010.10 - Upgrade
Upgrade
ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 6.17.0-1009.9 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 6.17.0-1009.9 - Upgrade
Upgrade
ubuntu/linux-raspito a version that resolves this vulnerability.Fixed in 6.17.0-1010.10 - Upgrade
Upgrade
ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 6.17.0-1008.9 - Upgrade
Upgrade
ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 6.17.0-19.19.1 - Configuration
Add a devlink between the consuming led-backlight device (for example, backlight-addon) and the supplying LED class device (for example, pca9632@62), rather than linking the consumer to the supplier's parent.
Linux kernel LED backlight driver devlink = add supplier link
Event History
Frequently Asked Questions
Which systems are most likely to be exposed to this issue?
Systems using an LED backlight device that consumes one or more LED class devices are affected by the faulty dependency link. The described failure is specifically triggered when removing a device-tree overlay containing the LED driver and its led-backlight consumer.
What does an attacker or triggering condition require?
The issue requires a configuration with an LED backlight linked to an LED supplied by a class device, followed by removal of the relevant device-tree overlay. The data does not describe a remote or unprivileged attack path.
What happens when the vulnerable configuration is triggered?
The dependency is created against the LED driver's parent, such as the I2C bus adapter, rather than the LED driver. This can allow the LED driver to be removed before the backlight device and result in a kernel NULL pointer dereference.
How can I determine whether my configuration is affected?
Review device-tree overlays for led-backlight nodes whose leds property references LEDs provided by another driver, such as a PCA9632 LED device. Environments that do not remove such overlays are not described as triggering the failure.