netdev - Re: [MPTCP] [PATCH net] mptcp: fix races between shutdown and recvmsg

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]

Date:   Wed, 10 Jun 2020 12:04:00 +0200
From:   Matthieu Baerts <matthieu.baerts@...sares.net>
To:     Paolo Abeni <pabeni@...hat.com>, netdev@...r.kernel.org
Cc:     "David S. Miller" <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>, mptcp@...ts.01.org
Subject: Re: [MPTCP] [PATCH net] mptcp: fix races between shutdown and recvmsg

Hi Paolo,

On 10/06/2020 10:47, Paolo Abeni wrote:
> The msk sk_shutdown flag is set by a workqueue, possibly
> introducing some delay in user-space notification. If the last
> subflow carries some data with the fin packet, the user space
> can wake-up before RCV_SHUTDOWN is set. If it executes unblocking
> recvmsg(), it may return with an error instead of eof.
> 
> Address the issue explicitly checking for eof in recvmsg(), when
> no data is found.
> 
> Fixes: 59832e246515 ("mptcp: subflow: check parent mptcp socket on subflow state change")
> Signed-off-by: Paolo Abeni <pabeni@...hat.com>

Thank you for the patch, it looks good to me!

Reviewed-by: Matthieu Baerts <matthieu.baerts@...sares.net>

Cheers,
Matt
-- 
Matthieu Baerts | R&D Engineer
matthieu.baerts@...sares.net
Tessares SA | Hybrid Access Solutions
www.tessares.net
1 Avenue Jean Monnet, 1348 Louvain-la-Neuve, Belgium