Re: [PATCH] thinkpad_acpi: fix: use scnprintf instead of snprintf.

Henrique de Moraes Holschuh
2021-01-15T19:28:45Z

On Wed, 06 Jan 2021, Joe Perches wrote:
> On Wed, 2021-01-06 at 14:36 +0800, YANG LI wrote:
> > The snprintf() function returns the number of characters which would
> > have been printed if there were enough space, but the scnprintf()
> > returns the number of characters which were actually printed. If the
> > buffer is not large enough, then using snprintf() would result in a
> > read overflow and an information leak. This error was found with the
> > help of coccicheck.
>
> In all cases, the buffer _is_ large enough.

Thank you for double-checking!

> _show function lengths are OK for all the uses with PAGE_SIZE.
> And it's probably better to use sysfs_emit for all the _show functions

Indeed.

--
Henrique Holschuh