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Date:   Sat, 29 Aug 2020 11:36:48 -0400
From:   "J. Bruce Fields" <bfields@fieldses.org>
To:     Dinghao Liu <dinghao.liu@zju.edu.cn>
Cc:     kjlu@umn.edu, Trond Myklebust <trond.myklebust@hammerspace.com>,
        Anna Schumaker <anna.schumaker@netapp.com>,
        Chuck Lever <chuck.lever@oracle.com>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Scott Mayhew <smayhew@redhat.com>, linux-nfs@vger.kernel.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Ard Biesheuvel <ardb@kernel.org>
Subject: Re: [PATCH] gss_krb5: Fix memleak in krb5_make_rc4_seq_num
Message-ID: <20200829153648.GB20499@fieldses.org>
References: <20200827080252.26396-1-dinghao.liu@zju.edu.cn>
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This code is rarely if ever used, and there are pending patches to
remove it completely, so I don't think it's worth trying to fix a rare
memory leak at this point.

--b.

On Thu, Aug 27, 2020 at 04:02:50PM +0800, Dinghao Liu wrote:
> When kmalloc() fails, cipher should be freed
> just like when krb5_rc4_setup_seq_key() fails.
> 
> Fixes: e7afe6c1d486b ("sunrpc: fix 4 more call sites that were using stack memory with a scatterlist")
> Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
> ---
>  net/sunrpc/auth_gss/gss_krb5_seqnum.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/net/sunrpc/auth_gss/gss_krb5_seqnum.c b/net/sunrpc/auth_gss/gss_krb5_seqnum.c
> index 507105127095..88ca58d11082 100644
> --- a/net/sunrpc/auth_gss/gss_krb5_seqnum.c
> +++ b/net/sunrpc/auth_gss/gss_krb5_seqnum.c
> @@ -53,8 +53,10 @@ krb5_make_rc4_seq_num(struct krb5_ctx *kctx, int direction, s32 seqnum,
>  		return PTR_ERR(cipher);
>  
>  	plain = kmalloc(8, GFP_NOFS);
> -	if (!plain)
> -		return -ENOMEM;
> +	if (!plain) {
> +		code = -ENOMEM;
> +		goto out;
> +	}
>  
>  	plain[0] = (unsigned char) ((seqnum >> 24) & 0xff);
>  	plain[1] = (unsigned char) ((seqnum >> 16) & 0xff);
> -- 
> 2.17.1