Re: [PATCH] hfs: Sanity check the root record

[Jan Kara]

On Tue 26-11-24 09:21:50, Leo Stone wrote:
> Hello,
> 
> On Tue, Nov 26, 2024 at 10:33:13AM +0100, Jan Kara wrote:
> > 
> > This certainly won't hurt but shouldn't we also add some stricter checks
> > for entry length so that we know we've loaded enough data to have full info
> > about the root dir?
> 
> Yes, that would be a good idea. Do we want to keep the existing checks
> and just make sure we have at least enough to initialize the struct:
> 
> if (fd.entrylength > sizeof(rec) || fd.entrylength < 0 ||
>     fd.entrylength < sizeof(rec.dir)) {
> 	res = -EIO;
> 	goto bail_hfs_find;
> }
> 
> Or be even stricter and only accept the exact length:
> 
> if (fd.entrylength != sizeof(rec.dir)) {
> 	res = -EIO;
> 	goto bail_hfs_find;
> }

Yes, this strict check would make sense to me. I just don't know HFS good
enough whether this is a safe assumption to make so it would be good to
test with some HFS filesystem.

								Honza
-- 
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR