Subject: Re: [PATCH] net: tls: fix possible info leak in
 tls_set_device_offload()
To:     Hangyu Hua <hbh25y@gmail.com>, <borisp@nvidia.com>,
        <john.fastabend@gmail.com>, <kuba@kernel.org>,
        <davem@davemloft.net>, <edumazet@google.com>, <pabeni@redhat.com>
CC:     <netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>
References: <20230223090508.443157-1-hbh25y@gmail.com>
From:   Yunsheng Lin <linyunsheng@huawei.com>
Message-ID: <60e2ed41-1c88-3780-e4c4-550cef8f7c91@huawei.com>
Date:   Thu, 23 Feb 2023 17:25:13 +0800
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On 2023/2/23 17:05, Hangyu Hua wrote:
> After tls_set_device_offload() fails, we enter tls_set_sw_offload(). But
> tls_set_sw_offload can't set cctx->iv and cctx->rec_seq to NULL if it fails
> before kmalloc cctx->iv. This may cause info leak when we call
> do_tls_getsockopt_conf().

Should we use kfree_sensitive() here if info leaking is what we want to
avoid?

> 
> Fixes: e8f69799810c ("net/tls: Add generic NIC offload infrastructure")
> Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
> ---
>  net/tls/tls_device.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
> index 6c593788dc25..a63f6f727f58 100644
> --- a/net/tls/tls_device.c
> +++ b/net/tls/tls_device.c
> @@ -1241,8 +1241,10 @@ int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
>  	kfree(start_marker_record);
>  free_rec_seq:
>  	kfree(ctx->tx.rec_seq);
> +	ctx->tx.rec_seq = NULL;
>  free_iv:
>  	kfree(ctx->tx.iv);
> +	ctx->tx.iv = NULL;
>  release_netdev:
>  	dev_put(netdev);
>  	return rc;
>