Re: [PATCH v2 0/7] iio: fix possible race condition during access of available info lists

From: Peter Rosin
Date: Tue Oct 08 2024 - 07:39:12 EST


Hi!

2024-10-07 at 10:37, Matteo Martelli wrote:
> Some iio drivers currently share an available info list buffer that
> might be changed while iio core prints it to sysfs. This could cause the
> buffer shared with iio core to be corrupted. However, note that I was
> able to trigger the race condition only by adding a delay between each
> sysfs_emit_at calls in the iio_format_list() to force the concurrent
> access to the shared available list buffer.
>
> This patch set extends the iio APIs and fixes some affected drivers.
>
> Summary:
> - Patch 1: iio core: introduce a iio info release callback to let
> drivers share a copy of their available info list and later free it.
>
> - Patch 2: pac1921: handle the current scale available info via the
> read_avail+read_avail_release_resource APIs instead of using an ad-hoc
> ext_info attribute. The latter was used to avoid the risk of a race in
> the available list.
>
> - Patch 3,4: ad7192, as73211: fix the possible race in the drivers by
> copying/releasing the affected available lists.
>
> - Patch 5: inkern: make consumers copy and release the available info
> lists of their producers, necessary after patch 1.
>
> - Patch 6,7: iio-mux, iio-rescale, dpot-dac, ingenic-battery: adapt
> consumers to inkern API change by freeing the now copied available
> lists of their producers.

The series not bisectable because of leaks. I'm not certain if a simple
reordering is all that is needed or if some things have to be squashed?

Cheers,
Peter