linux-kernel - Re: [RFC PATCH 2/8] btrfs: move kfree out of btrfs_create

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <74034783-1715-4020-a22b-45db6cd389be@suse.com>
Date: Thu, 13 Nov 2025 07:00:53 +1030
From: Qu Wenruo <wqu@...e.com>
To: Gladyshev Ilya <foxido@...ido.dev>
Cc: Chris Mason <clm@...com>, David Sterba <dsterba@...e.com>,
 linux-btrfs@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [RFC PATCH 2/8] btrfs: move kfree out of btrfs_create_qgroup's
 cleanup path



在 2025/11/13 05:19, Gladyshev Ilya 写道:
> Relocate kfree() from the generic cleanup path to the specific error
> exit where the allocation could leak. This prepares for future
> simplification by allowing removal of the 'out' label and use of
> mutex_guard for cleaner resource management.
> 
> Signed-off-by: Gladyshev Ilya <foxido@...ido.dev>
> ---
>   fs/btrfs/qgroup.c | 8 ++++----
>   1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
> index 9904bcfd3a60..a8474d0a9c58 100644
> --- a/fs/btrfs/qgroup.c
> +++ b/fs/btrfs/qgroup.c
> @@ -1659,7 +1659,7 @@ int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
>   	struct btrfs_fs_info *fs_info = trans->fs_info;
>   	struct btrfs_root *quota_root;
>   	struct btrfs_qgroup *qgroup;
> -	struct btrfs_qgroup *prealloc = NULL;
> +	struct btrfs_qgroup *prealloc;
>   	int ret = 0;
>   
>   	mutex_lock(&fs_info->qgroup_ioctl_lock);
> @@ -1681,18 +1681,18 @@ int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
>   	}
>   
>   	ret = add_qgroup_item(trans, quota_root, qgroupid);
> -	if (ret)
> +	if (ret) {
> +		kfree(prealloc);
>   		goto out;
> +	}
>   
>   	spin_lock(&fs_info->qgroup_lock);
>   	qgroup = add_qgroup_rb(fs_info, prealloc, qgroupid);
>   	spin_unlock(&fs_info->qgroup_lock);
> -	prealloc = NULL;
>   
>   	ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
>   out:
>   	mutex_unlock(&fs_info->qgroup_ioctl_lock);

You're not on the latest for-next branch, which has the following patch 
applied doing the extra sanity checks:

https://lore.kernel.org/linux-btrfs/20251024102143.236665-5-mssola@mssola.com/

With the extra ASSERT()s, the old code makes more sense.

Thanks,
Qu
> -	kfree(prealloc);
>   	return ret;
>   }
>