Re: [PATCH v20 07/12] ALSA: virtio: validate indirect capture appl_ptr accounting

[sashiko-bot@kernel.org]

> Retain references to the pages backing ALSA's vmalloc buffer until its
> queued I/O messages are freed. On NOMMU systems, use driver-owned memory
> for DMA and copy playback data before submission and capture data after
> completion, so ALSA buffer release cannot invalidate an active request.
> 
> Validate the PCM buffer and each period before building scatterlists.
> Require a successful full-period response for ordinary capture before
> advancing its pointer. Each descriptor targets a fixed ring slice, so a
> short response would expose the unwritten remainder as captured data.
> 
> Require whole-byte periods whose total matches the negotiated buffer.
> Check offset, length and the final message index before indexing the
> message array, including empty transfers and arithmetic wraparound.
> 
> Seed the ordinary capture ring once per prepare. Native STOP preserves
> [ ... ]
> 
> Retain PCM DMA pages and validate full fixed-slot completions. Account the successfully seeded RX ring as full so completed capture data stays reserved until appl_ptr consumes it.
> 
> Bound ordinary indirect capture appl_ptr consumption to completed, unacknowledged capture bytes before invoking the indirect transfer helper. Reject positive advances before RX ring seeding and reject frame deltas not aligned to runtime->min_align before byte conversion.
> Signed-off-by: Joonho Lee <mynameisjune111@gmail.com>

Sashiko has reviewed this patch and found no issues.

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Sashiko AI review · https://sashiko.dev/#/patchset/20261107143422.29319-1-mynameisjune111@gmail.com?part=7