e2fsprogs coverity patch <cid-11.diff>

e2fsprogs coverity patch <cid-11.diff>

[Brian D. Behlendorf]

Lawrence Livermore National Labs recently ran the source code
analysis tool Coverity over the e2fsprogs-1.39 source to see 
if it would identify any significant bugs.  The analysis
turned up 38 mostly minor issues which are enumerated here
with patches.  We went through and resolved these issues
but would love to see these mostly minor changes reviewed
and commited upstream.

Thanks,
Brian Behlendorf <behlendorf1@llnl.gov>, and
Herb Wartens <wartens2@llnl.gov>

-----------------------------------------------------------------------------
Coverity ID: 11: Overrun Static

Add an extra byte to EXT2_NAME_LEN in the static allocation for the
required trailing null.  This allows filenames up to the maximum
length of EXT2_NAME_LEN withover an overrun.

Index: e2fsprogs+chaos/debugfs/ls.c
===================================================================
--- e2fsprogs+chaos.orig/debugfs/ls.c
+++ e2fsprogs+chaos/debugfs/ls.c
@@ -52,14 +52,14 @@ static int list_dir_proc(ext2_ino_t dir 
 	ext2_ino_t		ino;
 	struct tm		*tm_p;
 	time_t			modtime;
-	char			name[EXT2_NAME_LEN];
+	char			name[EXT2_NAME_LEN + 1];
 	char			tmp[EXT2_NAME_LEN + 16];
 	char			datestr[80];
 	char			lbr, rbr;
 	int			thislen;
 	struct list_dir_struct *ls = (struct list_dir_struct *) private;
 
-	thislen = ((dirent->name_len & 0xFF) < EXT2_NAME_LEN) ?
+	thislen = ((dirent->name_len & 0xFF) <= EXT2_NAME_LEN) ?
 		(dirent->name_len & 0xFF) : EXT2_NAME_LEN;
 	strncpy(name, dirent->name, thislen);
 	name[thislen] = '\0';

Re: e2fsprogs coverity patch <cid-11.diff>

[Theodore Tso]

On Fri, Feb 09, 2007 at 06:11:09PM -0800, Brian D. Behlendorf wrote:
> Add an extra byte to EXT2_NAME_LEN in the static allocation for the
> required trailing null.  This allows filenames up to the maximum
> length of EXT2_NAME_LEN withover an overrun.
> 
> Coverity ID: 11: Overrun Static
> 
> -	thislen = ((dirent->name_len & 0xFF) < EXT2_NAME_LEN) ?
> +	thislen = ((dirent->name_len & 0xFF) <= EXT2_NAME_LEN) ?
>  		(dirent->name_len & 0xFF) : EXT2_NAME_LEN;

This change is largely meaningless/unnecessary, since if
*dirent->name_len & 0xFF) is equal to EXT2_NAME_LEN it doesn't matter
which path is chosen; was there a reason for the change.

					- Ted

Re: e2fsprogs coverity patch <cid-11.diff>

[Dave Kleikamp]

On Wed, 2007-03-21 at 14:54 -0400, Theodore Tso wrote:
> On Fri, Feb 09, 2007 at 06:11:09PM -0800, Brian D. Behlendorf wrote:
> > Add an extra byte to EXT2_NAME_LEN in the static allocation for the
> > required trailing null.  This allows filenames up to the maximum
> > length of EXT2_NAME_LEN withover an overrun.
> > 
> > Coverity ID: 11: Overrun Static
> > 
> > -	thislen = ((dirent->name_len & 0xFF) < EXT2_NAME_LEN) ?
> > +	thislen = ((dirent->name_len & 0xFF) <= EXT2_NAME_LEN) ?
> >  		(dirent->name_len & 0xFF) : EXT2_NAME_LEN;
> 
> This change is largely meaningless/unnecessary, since if
> *dirent->name_len & 0xFF) is equal to EXT2_NAME_LEN it doesn't matter
> which path is chosen; was there a reason for the change.

#define EXT2_NAME_LEN 255

How about this?

	thislen = dirent->name_len & 0xFF;

-- 
David Kleikamp
IBM Linux Technology Center

Re: e2fsprogs coverity patch <cid-11.diff>

[Theodore Tso]

On Wed, Mar 21, 2007 at 02:14:15PM -0500, Dave Kleikamp wrote:
> > > Coverity ID: 11: Overrun Static
> > > 
> > > -	thislen = ((dirent->name_len & 0xFF) < EXT2_NAME_LEN) ?
> > > +	thislen = ((dirent->name_len & 0xFF) <= EXT2_NAME_LEN) ?
> > >  		(dirent->name_len & 0xFF) : EXT2_NAME_LEN;
> > 
> > This change is largely meaningless/unnecessary, since if
> > *dirent->name_len & 0xFF) is equal to EXT2_NAME_LEN it doesn't matter
> > which path is chosen; was there a reason for the change.
> 
> #define EXT2_NAME_LEN 255
> 
> How about this?
> 
> 	thislen = dirent->name_len & 0xFF;

It's unlikely that EXT2_NAME_LEN will ever change, so yes, that's
probably a good idea.  I've alrady committed the patch, though so
we'll do it later.

						- Ted