Re: [PATCH V2 7/9 linux-next] udf: return error when newIndex is 0 in udf_translate_to_linux()

[Jan Kara <jack@suse.cz>]

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On Thu 09-04-15 10:51:05, Jan Kara wrote:
> On Wed 08-04-15 21:23:57, Fabian Frederick wrote:
> > udf_get_filename() and its callsites considered 0 as an error
> > without propagating an error value.
> > 
> > udf_translate_to_linux() now returns -EINVAL when newIndex is 0.
> > other functions are updated accordingly.
> > 
> > Signed-off-by: Fabian Frederick <fabf@skynet.be>
>   I've updated modified this patch and the changelog to do the check for
> zero length filename in udf_get_filename() and not in
> udf_translate_to_linux(). Since the second is just a general conversion
> function and zero length string as a result is fine with that. But zero
> length file name isn't correct and that's why udf_get_filename() should
> generate the error. I've also updated the changelog accordingly.
  Attached is the resulting patch for reference.

								Honza

> >  fs/udf/dir.c     | 2 +-
> >  fs/udf/namei.c   | 2 +-
> >  fs/udf/unicode.c | 4 ++--
> >  3 files changed, 4 insertions(+), 4 deletions(-)
> > 
> > diff --git a/fs/udf/dir.c b/fs/udf/dir.c
> > index fcf227e..541d9c6 100644
> > --- a/fs/udf/dir.c
> > +++ b/fs/udf/dir.c
> > @@ -168,7 +168,7 @@ static int udf_readdir(struct file *file, struct dir_context *ctx)
> >  		}
> >  
> >  		flen = udf_get_filename(sb, nameptr, lfi, fname, UDF_NAME_LEN);
> > -		if (flen <= 0)
> > +		if (flen < 0)
> >  			continue;
> >  
> >  		tloc = lelb_to_cpu(cfi.icb.extLocation);
> > diff --git a/fs/udf/namei.c b/fs/udf/namei.c
> > index 59b340c..dd648b7 100644
> > --- a/fs/udf/namei.c
> > +++ b/fs/udf/namei.c
> > @@ -234,7 +234,7 @@ static struct fileIdentDesc *udf_find_entry(struct inode *dir,
> >  			continue;
> >  
> >  		flen = udf_get_filename(sb, nameptr, lfi, fname, UDF_NAME_LEN);
> > -		if ((flen > 0) && udf_match(flen, fname, child->len,
> > +		if ((flen >= 0) && udf_match(flen, fname, child->len,
> >  					    child->name))
> >  			goto out_ok;
> >  	}
> > diff --git a/fs/udf/unicode.c b/fs/udf/unicode.c
> > index f37123b..3b1efbb 100644
> > --- a/fs/udf/unicode.c
> > +++ b/fs/udf/unicode.c
> > @@ -333,7 +333,7 @@ int udf_get_filename(struct super_block *sb, uint8_t *sname, int slen,
> >  		     uint8_t *dname, int dlen)
> >  {
> >  	struct ustr *filename, *unifilename;
> > -	int ret = 0;
> > +	int ret;
> >  
> >  	if (!slen)
> >  		return -EIO;
> > @@ -492,5 +492,5 @@ static int udf_translate_to_linux(uint8_t *newName, int newLen,
> >  		}
> >  	}
> >  
> > -	return newIndex;
> > +	return newIndex ? : -EINVAL;
> >  }
> > -- 
> > 1.9.1
> > 
> -- 
> Jan Kara <jack@suse.cz>
> SUSE Labs, CR
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR

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>From 837a2883619b33784250db651a18d2a80c822f6d Mon Sep 17 00:00:00 2001
From: Fabian Frederick <fabf@skynet.be>
Date: Wed, 8 Apr 2015 21:23:57 +0200
Subject: [PATCH 7/8] udf: Make udf_get_filename() return error instead of 0
 length file name

Zero length file name isn't really valid. So check the length of the
final file name generated by udf_translate_to_linux() and return -EINVAL
instead of zero length file name. Update caller of udf_get_filename() to
not check for 0 return value.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/udf/dir.c     | 2 +-
 fs/udf/unicode.c | 5 ++++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/udf/dir.c b/fs/udf/dir.c
index fcf227eb2c51..541d9c65014d 100644
--- a/fs/udf/dir.c
+++ b/fs/udf/dir.c
@@ -168,7 +168,7 @@ static int udf_readdir(struct file *file, struct dir_context *ctx)
 		}
 
 		flen = udf_get_filename(sb, nameptr, lfi, fname, UDF_NAME_LEN);
-		if (flen <= 0)
+		if (flen < 0)
 			continue;
 
 		tloc = lelb_to_cpu(cfi.icb.extLocation);
diff --git a/fs/udf/unicode.c b/fs/udf/unicode.c
index 97b23b0f9713..ab478e62baae 100644
--- a/fs/udf/unicode.c
+++ b/fs/udf/unicode.c
@@ -333,7 +333,7 @@ int udf_get_filename(struct super_block *sb, uint8_t *sname, int slen,
 		     uint8_t *dname, int dlen)
 {
 	struct ustr *filename, *unifilename;
-	int ret = 0;
+	int ret;
 
 	if (!slen)
 		return -EIO;
@@ -370,6 +370,9 @@ int udf_get_filename(struct super_block *sb, uint8_t *sname, int slen,
 	ret = udf_translate_to_linux(dname, dlen,
 				     filename->u_name, filename->u_len,
 				     unifilename->u_name, unifilename->u_len);
+	/* Zero length filename isn't valid... */
+	if (ret == 0)
+		ret = -EINVAL;
 out2:
 	kfree(unifilename);
 out1:
-- 
2.1.4