Re: [PATCH 3/3] fs/ntfs3: Fix error handling in indx_insert_into_root()

[Konstantin Komarov]

On 24.08.2021 10:51, Dan Carpenter wrote:
> There are three bugs in this code:
> 1) If indx_get_root() fails, then return -EINVAL instead of success.
> 2) On the "/* make root external */" -EOPNOTSUPP; error path it should
>    free "re" but it has a memory leak.
> 3) If indx_new() fails then it will lead to an error pointer dereference
>    when we call put_indx_node().
> 
> I've re-written the error handling to be more clear.
> 
> Fixes: 82cae269cfa9 ("fs/ntfs3: Add initialization of super block")
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> ---
>  fs/ntfs3/index.c | 36 ++++++++++++++++--------------------
>  1 file changed, 16 insertions(+), 20 deletions(-)
> 
> diff --git a/fs/ntfs3/index.c b/fs/ntfs3/index.c
> index 489e0fffbc75..4f2d24010386 100644
> --- a/fs/ntfs3/index.c
> +++ b/fs/ntfs3/index.c
> @@ -1554,12 +1554,12 @@ static int indx_insert_into_root(struct ntfs_index *indx, struct ntfs_inode *ni,
>  	u32 root_size, new_root_size;
>  	struct ntfs_sb_info *sbi;
>  	int ds_root;
> -	struct INDEX_ROOT *root, *a_root = NULL;
> +	struct INDEX_ROOT *root, *a_root;
>  
>  	/* Get the record this root placed in */
>  	root = indx_get_root(indx, ni, &attr, &mi);
>  	if (!root)
> -		goto out;
> +		return -EINVAL;
>  
>  	/*
>  	 * Try easy case:
> @@ -1591,10 +1591,8 @@ static int indx_insert_into_root(struct ntfs_index *indx, struct ntfs_inode *ni,
>  
>  	/* Make a copy of root attribute to restore if error */
>  	a_root = ntfs_memdup(attr, asize);
> -	if (!a_root) {
> -		err = -ENOMEM;
> -		goto out;
> -	}
> +	if (!a_root)
> +		return -ENOMEM;
>  
>  	/* copy all the non-end entries from the index root to the new buffer.*/
>  	to_move = 0;
> @@ -1604,7 +1602,7 @@ static int indx_insert_into_root(struct ntfs_index *indx, struct ntfs_inode *ni,
>  	for (e = e0;; e = hdr_next_de(hdr, e)) {
>  		if (!e) {
>  			err = -EINVAL;
> -			goto out;
> +			goto out_free_root;
>  		}
>  
>  		if (de_is_last(e))
> @@ -1612,14 +1610,13 @@ static int indx_insert_into_root(struct ntfs_index *indx, struct ntfs_inode *ni,
>  		to_move += le16_to_cpu(e->size);
>  	}
>  
> -	n = NULL;
>  	if (!to_move) {
>  		re = NULL;
>  	} else {
>  		re = ntfs_memdup(e0, to_move);
>  		if (!re) {
>  			err = -ENOMEM;
> -			goto out;
> +			goto out_free_root;
>  		}
>  	}
>  
> @@ -1636,7 +1633,7 @@ static int indx_insert_into_root(struct ntfs_index *indx, struct ntfs_inode *ni,
>  	if (ds_root > 0 && used + ds_root > sbi->max_bytes_per_attr) {
>  		/* make root external */
>  		err = -EOPNOTSUPP;
> -		goto out;
> +		goto out_free_re;
>  	}
>  
>  	if (ds_root)
> @@ -1666,7 +1663,7 @@ static int indx_insert_into_root(struct ntfs_index *indx, struct ntfs_inode *ni,
>  		/* bug? */
>  		ntfs_set_state(sbi, NTFS_DIRTY_ERROR);
>  		err = -EINVAL;
> -		goto out1;
> +		goto out_free_re;
>  	}
>  
>  	if (err) {
> @@ -1677,7 +1674,7 @@ static int indx_insert_into_root(struct ntfs_index *indx, struct ntfs_inode *ni,
>  			/* bug? */
>  			ntfs_set_state(sbi, NTFS_DIRTY_ERROR);
>  		}
> -		goto out1;
> +		goto out_free_re;
>  	}
>  
>  	e = (struct NTFS_DE *)(root + 1);
> @@ -1688,7 +1685,7 @@ static int indx_insert_into_root(struct ntfs_index *indx, struct ntfs_inode *ni,
>  	n = indx_new(indx, ni, new_vbn, sub_vbn);
>  	if (IS_ERR(n)) {
>  		err = PTR_ERR(n);
> -		goto out1;
> +		goto out_free_re;
>  	}
>  
>  	hdr = &n->index->ihdr;
> @@ -1715,7 +1712,7 @@ static int indx_insert_into_root(struct ntfs_index *indx, struct ntfs_inode *ni,
>  		put_indx_node(n);
>  		fnd_clear(fnd);
>  		err = indx_insert_entry(indx, ni, new_de, ctx, fnd);
> -		goto out;
> +		goto out_free_root;
>  	}
>  
>  	/*
> @@ -1725,7 +1722,7 @@ static int indx_insert_into_root(struct ntfs_index *indx, struct ntfs_inode *ni,
>  	e = hdr_insert_de(indx, hdr, new_de, NULL, ctx);
>  	if (!e) {
>  		err = -EINVAL;
> -		goto out1;
> +		goto out_put_n;
>  	}
>  	fnd_push(fnd, n, e);
>  
> @@ -1734,12 +1731,11 @@ static int indx_insert_into_root(struct ntfs_index *indx, struct ntfs_inode *ni,
>  
>  	n = NULL;
>  
> -out1:
> +out_put_n:
> +	put_indx_node(n);
> +out_free_re:
>  	ntfs_free(re);
> -	if (n)
> -		put_indx_node(n);
> -
> -out:
> +out_free_root:
>  	ntfs_free(a_root);
>  	return err;
>  }
> 

Hi, Dan!

Applied all 3 patches, thanks!