Re: [PATCH] PCI: Fix unmasked value in pci_generic_config_write32()

[sashiko-bot@kernel.org]

> When writing less than 4 bytes, pci_generic_config_write32() uses a
> read-modify-write sequence to protect adjacent bytes. The code comment
> states the goal is to "merge in the <size> bits we intend to write".
> 
> However the code does not mask the incoming 'val' before shifting it.
> Since the function 'pci_generic_config_write32()' accepts a 'u32', a
> caller could pass a value with extra bits set outside the intended write
> size, those extra bits will shift into the adjacent bytes and corrupt them.
> 
> Fix this my masking 'val' before the shift so only the target bytes are
> written. This makes the code do what the comment says and matches the
> read function, pci_generic_config_read32().
> 
> Fixes: 1f94a94f67e10 ("PCI: Add generic config accessors")
> Signed-off-by: Mohamad Raizudeen <raizudeen.kerneldev@gmail.com>

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

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Sashiko AI review · https://sashiko.dev/#/patchset/20260727080643.4949-1-raizudeen.kerneldev@gmail.com?part=1