linux-ext4 - Re: [PATCH] jbd2: don't leak memory if setting up journal fails

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Date:   Wed, 15 Mar 2017 12:39:50 +0100
From:   Jan Kara <jack@...e.cz>
To:     Eric Biggers <ebiggers3@...il.com>
Cc:     linux-ext4@...r.kernel.org, Theodore Ts'o <tytso@....edu>,
        Jan Kara <jack@...e.com>, Eric Biggers <ebiggers@...gle.com>
Subject: Re: [PATCH] jbd2: don't leak memory if setting up journal fails

On Tue 14-03-17 21:19:55, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@...gle.com>
> 
> In journal_init_common(), if we failed to allocate the j_wbuf array, or
> if we failed to create the buffer_head for the journal superblock, we
> leaked the memory allocated for the revocation tables.  Fix this.
> 
> Signed-off-by: Eric Biggers <ebiggers@...gle.com>

Looks good. You can add:

Reviewed-by: Jan Kara <jack@...e.cz>

								Honza

> ---
>  fs/jbd2/journal.c | 22 +++++++++++-----------
>  fs/jbd2/revoke.c  |  1 +
>  2 files changed, 12 insertions(+), 11 deletions(-)
> 
> diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
> index a1a359bfcc9c..5adc2fb62b0f 100644
> --- a/fs/jbd2/journal.c
> +++ b/fs/jbd2/journal.c
> @@ -1125,10 +1125,8 @@ static journal_t *journal_init_common(struct block_device *bdev,
>  
>  	/* Set up a default-sized revoke table for the new mount. */
>  	err = jbd2_journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH);
> -	if (err) {
> -		kfree(journal);
> -		return NULL;
> -	}
> +	if (err)
> +		goto err_cleanup;
>  
>  	spin_lock_init(&journal->j_history_lock);
>  
> @@ -1145,23 +1143,25 @@ static journal_t *journal_init_common(struct block_device *bdev,
>  	journal->j_wbufsize = n;
>  	journal->j_wbuf = kmalloc_array(n, sizeof(struct buffer_head *),
>  					GFP_KERNEL);
> -	if (!journal->j_wbuf) {
> -		kfree(journal);
> -		return NULL;
> -	}
> +	if (!journal->j_wbuf)
> +		goto err_cleanup;
>  
>  	bh = getblk_unmovable(journal->j_dev, start, journal->j_blocksize);
>  	if (!bh) {
>  		pr_err("%s: Cannot get buffer for journal superblock\n",
>  			__func__);
> -		kfree(journal->j_wbuf);
> -		kfree(journal);
> -		return NULL;
> +		goto err_cleanup;
>  	}
>  	journal->j_sb_buffer = bh;
>  	journal->j_superblock = (journal_superblock_t *)bh->b_data;
>  
>  	return journal;
> +
> +err_cleanup:
> +	kfree(journal->j_wbuf);
> +	jbd2_journal_destroy_revoke(journal);
> +	kfree(journal);
> +	return NULL;
>  }
>  
>  /* jbd2_journal_init_dev and jbd2_journal_init_inode:
> diff --git a/fs/jbd2/revoke.c b/fs/jbd2/revoke.c
> index cfc38b552118..f9aefcda5854 100644
> --- a/fs/jbd2/revoke.c
> +++ b/fs/jbd2/revoke.c
> @@ -280,6 +280,7 @@ int jbd2_journal_init_revoke(journal_t *journal, int hash_size)
>  
>  fail1:
>  	jbd2_journal_destroy_revoke_table(journal->j_revoke_table[0]);
> +	journal->j_revoke_table[0] = NULL;
>  fail0:
>  	return -ENOMEM;
>  }
> -- 
> 2.12.0
> 
> 
-- 
Jan Kara <jack@...e.com>
SUSE Labs, CR