[patch] nfsd: fix comparison in fh_fsid_match()

[patch] nfsd: fix comparison in fh_fsid_match()

[Dan Carpenter]

We're supposed to be testing that the fh_fsid's match but because the
parenthesis are in the wrong place, then we only check the first
byte.

Fixes: 9558f2500a20 ('nfsd: add fh_fsid_match helper')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/fs/nfsd/nfsfh.h b/fs/nfsd/nfsfh.h
index 84cae20..f229204 100644
--- a/fs/nfsd/nfsfh.h
+++ b/fs/nfsd/nfsfh.h
@@ -200,7 +200,7 @@ static inline bool fh_fsid_match(struct knfsd_fh *fh1, struct knfsd_fh *fh2)
 {
 	if (fh1->fh_fsid_type != fh2->fh_fsid_type)
 		return false;
-	if (memcmp(fh1->fh_fsid, fh2->fh_fsid, key_len(fh1->fh_fsid_type) != 0))
+	if (memcmp(fh1->fh_fsid, fh2->fh_fsid, key_len(fh1->fh_fsid_type)) != 0)
 		return false;
 	return true;
 }

Re: [patch] nfsd: fix comparison in fh_fsid_match()

[Christoph Hellwig]

On Wed, Feb 11, 2015 at 04:08:32PM +0300, Dan Carpenter wrote:
> We're supposed to be testing that the fh_fsid's match but because the
> parenthesis are in the wrong place, then we only check the first
> byte.
> 
> Fixes: 9558f2500a20 ('nfsd: add fh_fsid_match helper')

Thanks, this looks good.  Is there an easy to setup way to check for
these sorts of errors?

Re: [patch] nfsd: fix comparison in fh_fsid_match()

[Dan Carpenter]

On Wed, Feb 11, 2015 at 02:21:19PM +0100, Christoph Hellwig wrote:
> On Wed, Feb 11, 2015 at 04:08:32PM +0300, Dan Carpenter wrote:
> > We're supposed to be testing that the fh_fsid's match but because the
> > parenthesis are in the wrong place, then we only check the first
> > byte.
> > 
> > Fixes: 9558f2500a20 ('nfsd: add fh_fsid_match helper')
> 
> Thanks, this looks good.  Is there an easy to setup way to check for
> these sorts of errors?

This is a Smatch check I wrote a couple years ago but it never found any
bugs until now so I didn't commit it.  I have done.  I'll push it out
later and Fengguang will eventually add it to the zero day tester bot.

regards,
dan carpenter

Re: [patch] nfsd: fix comparison in fh_fsid_match()

[J. Bruce Fields]

On Wed, Feb 11, 2015 at 04:08:32PM +0300, Dan Carpenter wrote:
> We're supposed to be testing that the fh_fsid's match but because the
> parenthesis are in the wrong place, then we only check the first
> byte.

Thanks, I'll pass this along!

--b.

> 
> Fixes: 9558f2500a20 ('nfsd: add fh_fsid_match helper')
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> 
> diff --git a/fs/nfsd/nfsfh.h b/fs/nfsd/nfsfh.h
> index 84cae20..f229204 100644
> --- a/fs/nfsd/nfsfh.h
> +++ b/fs/nfsd/nfsfh.h
> @@ -200,7 +200,7 @@ static inline bool fh_fsid_match(struct knfsd_fh *fh1, struct knfsd_fh *fh2)
>  {
>  	if (fh1->fh_fsid_type != fh2->fh_fsid_type)
>  		return false;
> -	if (memcmp(fh1->fh_fsid, fh2->fh_fsid, key_len(fh1->fh_fsid_type) != 0))
> +	if (memcmp(fh1->fh_fsid, fh2->fh_fsid, key_len(fh1->fh_fsid_type)) != 0)
>  		return false;
>  	return true;
>  }