Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
regulator: core: fix use_count leakage when handling boot-on
I found a use_count leakage towards supply regulator of rdev with boot-on option.
┌───────────────────┐ ┌───────────────────┐ │ regulator_dev A │ │ regulator_dev B │ │ (boot-on) │ │ (boot-on) │ │ use_count=0 │◀──supply──│ use_count=1 │ │ │ │ │ └───────────────────┘ └───────────────────┘
In case of rdev(A) configured with `regulator-boot-on’, the use_count of supplying regulator(B) will increment inside regulator_enable(rdev->supply).
Thus, B will acts like always-on, and further balanced regulator_enable/disable cannot actually disable it anymore.
However, B was also configured with `regulator-boot-on’, we wish it could be disabled afterwards.
Details
- Affected product:
- AlmaLinux 9.2 ESU , CentOS 6 ELS , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux 7 ELS , Oracle Linux 6 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , TuxCare 9.6 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- linux-hwe @ 4.15.0 (+15 more)
In the Linux kernel, the following vulnerability has been resolved:
regulator: core: fix use_count leakage when handling boot-on
I found a use_count leakage towards supply regulator of rdev with boot-on option.
┌───────────────────┐ ┌───────────────────┐ │ regulator_dev A │ │ regulator_dev B │ │ (boot-on) │ │ (boot-on) │ │ use_count=0 │◀──supply──│ use_count=1 │ │ │ │ │ └───────────────────┘ └───────────────────┘
In case of rdev(A) configured with `regulator-boot-on’, the use_count of supplying regulator(B) will increment inside regulator_enable(rdev->supply).
Thus, B will acts like always-on, and further balanced regulator_enable/disable cannot actually disable it anymore.
However, B was also configured with `regulator-boot-on’, we wish it could be disabled afterwards.