Re: [PATCH] scsi: sd: validate device-supplied mode sense lengths in cache_type_store

[James Bottomley]

On Fri, 2026-07-17 at 12:10 -0700, Jay Vadayath wrote:
> A malicious/emulated USB mass storage device (or any SCSI target) can
> return a MODE SENSE(6/10) response whose header_length plus
> block_descriptor_length is >= the size of the on-stack 64-byte
> buffer.

Malicious devices aren't usually part of our threat model because
checking every device action would result in enormous performance
drops.  There is an exception for USB devices because an arbitrary evil
maid could plug one into your laptop, but the usual threat model here
is unassisted data exfiltration or login bypass, but because of the
performance issue, you need to demonstrate a viable exploit.

Regards,

James