AW: [PATCH] bfs: prevent underflow in bfs_find_entry()

From: Walter Harms
Date: Tue Mar 10 2020 - 13:57:55 EST



________________________________________
Von: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Gesendet: Dienstag, 10. März 2020 10:06
An: Walter Harms
Cc: Tigran A. Aivazian; linux-kernel@xxxxxxxxxxxxxxx; kernel-janitors@xxxxxxxxxxxxxxx
Betreff: Re: [PATCH] bfs: prevent underflow in bfs_find_entry()

On Mon, Mar 09, 2020 at 08:40:28AM +0000, Walter Harms wrote:
> hi Dan,
> the namelen usage is fishy. It goes into bfs_namecmp()
> where it is checked for namelen < BFS_NAMELEN, leaving
> only the case ==.

The rule in bfs_namecmp() is that the name has to be NUL terminated if
there is enough space.

that raises the question why is there a len paramter in the first place.
Surely the writer can make sure that there is always a NUL terminated
string, then it would be possible the use a simple strcmp() and the
range check is useless and can be removed.

seems a question for the maintainer.

re,
wh