Re: [PATCH 1/2] vfs: parse: deal with zero length string value

From: Al Viro
Date: Tue Jun 28 2022 - 13:56:08 EST


On Tue, Jun 28, 2022 at 08:30:52AM +0800, Ian Kent wrote:
> Parsing an fs string that has zero length should result in the parameter
> being set to NULL so that downstream processing handles it correctly.
> For example, the proc mount table processing should print "(none)" in
> this case to preserve mount record field count, but if the value points
> to the NULL string this doesn't happen.

Hmmm... And what happens if you feed that to ->parse_param(), which
calls fs_parse(), which decides that param->key looks like a name of e.g.
u32 option and calls fs_param_is_u32() to see what's what? OOPS is a form
of rejection, I suppose, but...