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Date:   Mon, 19 Sep 2022 17:26:25 +0200
From:   Jan Kara <jack@suse.cz>
To:     Ye Bin <yebin10@huawei.com>
Cc:     tytso@mit.edu, adilger.kernel@dilger.ca,
        linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org,
        jack@suse.cz
Subject: Re: [PATCH -next 1/2] ext4: fix potential memory leak in
 ext4_fc_record_regions()
Message-ID: <20220919152625.36ao6aeyoamiaaor@quack3>
References: <20220919144021.2162295-1-yebin10@huawei.com>
 <20220919144021.2162295-2-yebin10@huawei.com>
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On Mon 19-09-22 22:40:20, Ye Bin wrote:
> As krealloc may return NULL, in this case 'state->fc_regions' may not be
> freed by krealloc, but 'state->fc_regions' already set NULL. Then will
> lead to 'state->fc_regions' memory leak.
> 
> Signed-off-by: Ye Bin <yebin10@huawei.com>

Looks good. Feel free to add:

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

								Honza

> ---
>  fs/ext4/fast_commit.c | 14 ++++++++------
>  1 file changed, 8 insertions(+), 6 deletions(-)
> 
> diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
> index 9217a588afd1..cc8c8db075ba 100644
> --- a/fs/ext4/fast_commit.c
> +++ b/fs/ext4/fast_commit.c
> @@ -1677,15 +1677,17 @@ int ext4_fc_record_regions(struct super_block *sb, int ino,
>  	if (replay && state->fc_regions_used != state->fc_regions_valid)
>  		state->fc_regions_used = state->fc_regions_valid;
>  	if (state->fc_regions_used == state->fc_regions_size) {
> +		struct ext4_fc_alloc_region *fc_regions;
> +
>  		state->fc_regions_size +=
>  			EXT4_FC_REPLAY_REALLOC_INCREMENT;
> -		state->fc_regions = krealloc(
> -					state->fc_regions,
> -					state->fc_regions_size *
> -					sizeof(struct ext4_fc_alloc_region),
> -					GFP_KERNEL);
> -		if (!state->fc_regions)
> +		fc_regions = krealloc(state->fc_regions,
> +				      state->fc_regions_size *
> +				      sizeof(struct ext4_fc_alloc_region),
> +				      GFP_KERNEL);
> +		if (!fc_regions)
>  			return -ENOMEM;
> +		state->fc_regions = fc_regions;
>  	}
>  	region = &state->fc_regions[state->fc_regions_used++];
>  	region->ino = ino;
> -- 
> 2.31.1
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR