On 2/26/2019 2:38 PM, Vakul Garg wrote:
>
>
>> -----Original Message-----
>> From: Boris Pismenny <bor...@mellanox.com>
>> Sent: Tuesday, February 26, 2019 5:43 PM
>> To: avia...@mellanox.com; davejwat...@fb.com;
>> john.fastab...@gmail.com; dan...@iogearbox.net; Vakul Garg
>> <vakul.g...@nxp.com>; netdev@vger.kernel.org
>> Cc: era...@mellanox.com; bor...@mellanox.com
>> Subject: [PATCH net 3/4] tls: Fix mixing between async capable and async
>>
>> From: Eran Ben Elisha <era...@mellanox.com>
>>
>> Today, tls_sw_recvmsg is capable of using asynchronous mode to handle
>> application data TLS records. Moreover, it assumes that if the cipher can be
>> handled asynchronously, then all packets will be processed asynchronously.
>>
>> However, this assumption is not always true.
>
> Could you please elaborate, what happens?
>
When decryption doesn't occur asynchronously e.g. return code is not
EINPROGRESS, then async should be turned off.
>> Specifically, for AES-GCM in
>> TLS1.2, it causes data corruption, and breaks user applications.
>>
>> This patch fixes this problem by separating the async capability from the
>> decryption operation result.
>>
>> Fixes: c0ab4732d4c6 ("net/tls: Do not use async crypto for non-data
>> records")
>> Signed-off-by: Eran Ben Elisha <era...@mellanox.com>
>> Reviewed-by: Boris Pismenny <bor...@mellanox.com>
>> ---
>> net/tls/tls_sw.c | 15 +++++++++------
>> 1 file changed, 9 insertions(+), 6 deletions(-)
>>
>> diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index
>> 4afa67b00aaf..f515cd7e984e 100644
>> --- a/net/tls/tls_sw.c
>> +++ b/net/tls/tls_sw.c
>> @@ -1693,7 +1693,8 @@ int tls_sw_recvmsg(struct sock *sk,
>> bool zc = false;
>> int to_decrypt;
>> int chunk = 0;
>> - bool async;
>> + bool async_capable;
>> + bool async = false;
>>
>> skb = tls_wait_data(sk, psock, flags, timeo, &err);
>> if (!skb) {
>> @@ -1727,21 +1728,23 @@ int tls_sw_recvmsg(struct sock *sk,
>>
>> /* Do not use async mode if record is non-data */
>> if (ctx->control == TLS_RECORD_TYPE_DATA)
>> - async = ctx->async_capable;
>> + async_capable = ctx->async_capable;
>> else
>> - async = false;
>> + async_capable = false;
>>
>> err = decrypt_skb_update(sk, skb, &msg->msg_iter,
>> - &chunk, &zc, async);
>> + &chunk, &zc, async_capable);
>> if (err < 0 && err != -EINPROGRESS) {
>> tls_err_abort(sk, EBADMSG);
>> goto recv_end;
>> }
>>
>> - if (err == -EINPROGRESS)
>> + if (err == -EINPROGRESS && async_capable) {
> Why do we need to check 'async_capable'?
> Do we get err == -EINPROGRESS even when async_capable is false?
>
I've missed this. I'll remove this and send V2.
>> + async = true;
>> num_async++;
>> - else if (prot->version == TLS_1_3_VERSION)
>> + } else if (prot->version == TLS_1_3_VERSION) {
>> tlm->control = ctx->control;
>> + }
>>
>> /* If the type of records being processed is not known yet,
>> * set it to record type just dequeued. If it is already known,
>> --
>> 2.12.2
>
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