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Date:   Wed, 17 Apr 2019 13:14:08 +0200
From:   Jan Kara <jack@suse.cz>
To:     Wenwen Wang <wang6495@umn.edu>
Cc:     Jan Kara <jack@suse.com>, open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] udf: fix an uninitialized read bug and remove dead
 code
Message-ID: <20190417111408.GB26435@quack2.suse.cz>
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On Mon 15-04-19 12:58:06, Wenwen Wang wrote:
> In udf_lookup(), the pointer 'fi' is a local variable initialized by the
> return value of the function call udf_find_entry(). However, if the macro
> 'UDF_RECOVERY' is defined, this variable will become uninitialized if the
> else branch is not taken, which can potentially cause incorrect results in
> the following execution.
> 
> To fix this issue, this patch drops the whole code in the ifdef
> 'UDF_RECOVERY' region, as it is dead code.
> 
> Signed-off-by: Wenwen Wang <wang6495@umn.edu>

Thanks for the patch. I've added it to my tree.

								Honza

> ---
>  fs/udf/namei.c | 15 ---------------
>  1 file changed, 15 deletions(-)
> 
> diff --git a/fs/udf/namei.c b/fs/udf/namei.c
> index 58cc241..77b6d89 100644
> --- a/fs/udf/namei.c
> +++ b/fs/udf/namei.c
> @@ -304,21 +304,6 @@ static struct dentry *udf_lookup(struct inode *dir, struct dentry *dentry,
>  	if (dentry->d_name.len > UDF_NAME_LEN)
>  		return ERR_PTR(-ENAMETOOLONG);
>  
> -#ifdef UDF_RECOVERY
> -	/* temporary shorthand for specifying files by inode number */
> -	if (!strncmp(dentry->d_name.name, ".B=", 3)) {
> -		struct kernel_lb_addr lb = {
> -			.logicalBlockNum = 0,
> -			.partitionReferenceNum =
> -				simple_strtoul(dentry->d_name.name + 3,
> -						NULL, 0),
> -		};
> -		inode = udf_iget(dir->i_sb, lb);
> -		if (IS_ERR(inode))
> -			return inode;
> -	} else
> -#endif /* UDF_RECOVERY */
> -
>  	fi = udf_find_entry(dir, &dentry->d_name, &fibh, &cfi);
>  	if (IS_ERR(fi))
>  		return ERR_CAST(fi);
> -- 
> 2.7.4
> 
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR