Bug 2400764 (CVE-2023-53472)

Summary: CVE-2023-53472 kernel: pwm: lpc32xx: Remove handling of PWM channels
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Description OSIDB Bzimport 2025-10-01 12:06:11 UTC 
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.
Comment 1 Jon Moroney 2025-10-01 20:25:46 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025100110-CVE-2023-53472-93cb@gregkh/T