Re: [PATCH v3] rust: pci: reject out-of-bounds IRQ vector indices

[sashiko-bot@kernel.org]

> From: Sophon Z <aiqubits@hotmail.com>
> 
> IrqVectorRegistration::index() accepts a usize and documents that
> out-of-bounds indices return EINVAL, while pci_irq_vector() takes an
> unsigned int.
> 
> Casting an index larger than u32::MAX wraps it before the PCI core can
> validate it. In particular, u32::MAX + 1 becomes zero and can resolve to
> the first allocated vector. Values that fit in u32 but exceed
> MSI_MAX_INDEX can also reach msi_domain_get_virq() and trigger
> WARN_ON_ONCE.
> 
> Check the index against the registration length before entering the C
> API, and keep the usize-to-u32 conversion checked so the ABI boundary
> does not rely on an unchecked cast.
> 
> Fixes: 2fb7755b0a7e ("rust: pci: resolve IRQ in index() and embed IrqRequest in IrqVector")
> 
> Signed-off-by: Sophon Z <aiqubits@hotmail.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20260831-fix-pci-irq-vector-index-truncation-v3-1-a2103084d20e@hotmail.com?part=1