pwm: lpc32xx: Remove handling of PWM channels
In the Linux kernel, the following vulnerability has been resolved: pwm: lpc32xx: Remove handling of PWM channels Because LPC32xx PWM controllers have only a single output which is registered as the only PWM device/channel per controller, it is known in advance that pwm->hwpwm value is always 0. On basis of this fact simplify the code by removing operations with pwm->hwpwm, there is no controls which require channel number as input. Even though I wasn't aware at the time when I forward ported that patch, this fixes a null pointer dereference as lpc32xx->chip.pwms is NULL before devm_pwmchip_add() is called.
02 / AFFECTED SOFTWARE
Affected packages
1382 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: pwm: lpc32xx: Remove handling of PWM channels Because LPC32xx PWM controllers have only a single output which is registered as the only PWM device/channel per controller, it is known in advance that pwm->hwpwm value is always 0. On basis of this fact simplify the code by removing operations with pwm->hwpwm, there is no controls which require channel number as input. Even though I wasn't aware at the time when I forward ported that patch, this fixes a null pointer dereference as lpc32xx->chip.pwms is NULL before devm_pwmchip_add() is called.
05 / REFERENCES
Further evidence
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- https://git.kernel.org/stable/c/04301da4d87067a989f70ee56942bf9d97cd2a45
- https://git.kernel.org/stable/c/4aae44f65827f0213a7361cf9c32cfe06114473f
- https://git.kernel.org/stable/c/523f6268e86552a048975749251184c4e9a4b38f
- https://git.kernel.org/stable/c/5e22217c11424ef958ba28d03ff7167b4d7a8914
- https://git.kernel.org/stable/c/a2d9d884e84bfd37892219b1f55847f36d8e9901
- https://git.kernel.org/stable/c/a9a505f5b39d8fff1a55963a5e524c84639e98b2
- https://git.kernel.org/stable/c/abd9b2ee4047ccd980decbf26d61f9637604b1d5
- https://git.kernel.org/stable/c/e3a0ddbaf7f1f9ffc070718b417461ced3268758
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53472.json
- https://nvd.nist.gov/vuln/detail/CVE-2023-53472