netdev - Re: [PATCH v2 net] net/smc: postpone sk

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <e0b64b80-90e1-5aed-1ca4-f6d20ebac6b7@linux.ibm.com>
Date:   Mon, 23 May 2022 16:44:57 +0200
From:   Karsten Graul <kgraul@...ux.ibm.com>
To:     liuyacan@...p.netease.com
Cc:     davem@...emloft.net, edumazet@...gle.com, kuba@...nel.org,
        linux-kernel@...r.kernel.org, linux-s390@...r.kernel.org,
        netdev@...r.kernel.org, pabeni@...hat.com, ubraun@...ux.ibm.com
Subject: Re: [PATCH v2 net] net/smc: postpone sk_refcnt increment in connect()

On 23/05/2022 16:19, liuyacan@...p.netease.com wrote:
>> This is a rather unusual problem that can come up when fallback=true BEFORE smc_connect()
>> is called. But nevertheless, it is a problem.
>>
>> Right now I am not sure if it is okay when we NOT hold a ref to smc->sk during all fallback
>> processing. This change also conflicts with a patch that is already on net-next (3aba1030).
> 
> Do you mean put the ref to smc->sk during all fallback processing unconditionally and remove 
> the fallback branch sock_put() in __smc_release()?

What I had in mind was to eventually call sock_put() in __smc_release() even if sk->sk_state == SMC_INIT
(currently the extra check in the if() for sk->sk_state != SMC_INIT prevents the sock_put()), but only
when it is sure that we actually reached the sock_hold() in smc_connect() before.

But maybe we find out that the sock_hold() is not needed for fallback sockets, I don't know...