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From:   Christian Schoenebeck <linux_oss@crudebyte.com>
To:     Tyler Hicks <tyhicks@linux.microsoft.com>,
        Eric Van Hensbergen <ericvh@gmail.com>,
        Latchesar Ionkov <lucho@ionkov.net>,
        Dominique Martinet <asmadeus@codewreck.org>,
        Jianyong Wu <jianyong.wu@arm.com>,
        v9fs-developer@lists.sourceforge.net
Cc:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH 02/06] 9p: fix fid refcount leak in v9fs_vfs_get_link
Date:   Tue, 14 Jun 2022 15:19:55 +0200
Message-ID: <3172397.lbAG7NvT7i@silver>
In-Reply-To: <20220612085330.1451496-3-asmadeus@codewreck.org>
References: <20220612085330.1451496-1-asmadeus@codewreck.org>
 <20220612085330.1451496-3-asmadeus@codewreck.org>
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On Sonntag, 12. Juni 2022 10:53:25 CEST Dominique Martinet wrote:
> we check for protocol version later than required, after a fid has
> been obtained. Just move the version check earlier.
> 
> Fixes: 6636b6dcc3db ("9p: add refcount to p9_fid struct")
> Cc: stable@vger.kernel.org
> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
> ---

Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com>

>  fs/9p/vfs_inode.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
> index 55367ecb9442..18c780ffd4b5 100644
> --- a/fs/9p/vfs_inode.c
> +++ b/fs/9p/vfs_inode.c
> @@ -1250,15 +1250,15 @@ static const char *v9fs_vfs_get_link(struct dentry
> *dentry, return ERR_PTR(-ECHILD);
> 
>  	v9ses = v9fs_dentry2v9ses(dentry);
> -	fid = v9fs_fid_lookup(dentry);
> +	if (!v9fs_proto_dotu(v9ses))
> +		return ERR_PTR(-EBADF);
> +
>  	p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
> +	fid = v9fs_fid_lookup(dentry);
> 
>  	if (IS_ERR(fid))
>  		return ERR_CAST(fid);
> 
> -	if (!v9fs_proto_dotu(v9ses))
> -		return ERR_PTR(-EBADF);
> -
>  	st = p9_client_stat(fid);
>  	p9_client_clunk(fid);
>  	if (IS_ERR(st))