Re: [PATCH v6 mptcp-next 05/11] mptcp: fix MSG_PEEK stream corruption

[Paolo Abeni <pabeni@redhat.com>]

On 10/23/25 6:56 PM, Mat Martineau wrote:
> On Wed, 22 Oct 2025, Paolo Abeni wrote:
> 
>> If a MSG_PEEK | MSG_WAITALL read operation consumes all the bytes in the
>> receive queue and recvmsg() need to waits for more data - i.e. it's a
>> blocking one - upon arrival of the next packet the MPTCP protocol will
>> start again copying the oldest data present in the receive queue,
>> corrupting the data stream.
>>
>> Address the issue explicitly tracking the peeked sequence number,
>> restarting from the last peeked byte.
>>
>> Fixes: ca4fb892579f ("mptcp: add MSG_PEEK support")
>> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
>> ---
>> This may sound quite esoteric, but it will soon become very easy to
>> reproduce with mptcp_connect, thanks to the backlog.
> 
> Would it be good to apply this to -net?

FWIW, I'm fine with applying this to -net.

Thanks,

Paolo