From: Jakub Kicinski <kuba@kernel.org>
To: Eric Dumazet <edumazet@google.com>
Cc: Dmitry Safonov via B4 Relay
<devnull+0x7f454c46.gmail.com@kernel.org>,
0x7f454c46@gmail.com, "David S. Miller" <davem@davemloft.net>,
Paolo Abeni <pabeni@redhat.com>, Simon Horman <horms@kernel.org>,
David Ahern <dsahern@kernel.org>,
Ivan Delalande <colona@arista.com>,
Matthieu Baerts <matttbe@kernel.org>,
Mat Martineau <martineau@kernel.org>,
Geliang Tang <geliang@kernel.org>,
Boris Pismenny <borisp@nvidia.com>,
John Fastabend <john.fastabend@gmail.com>,
Davide Caratti <dcaratti@redhat.com>,
Kuniyuki Iwashima <kuniyu@amazon.com>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
mptcp@lists.linux.dev, stable@vger.kernel.org
Subject: Re: [PATCH net v2 0/5] Make TCP-MD5-diag slightly less broken
Date: Wed, 4 Dec 2024 17:13:51 -0800 [thread overview]
Message-ID: <20241204171351.52b8bb36@kernel.org> (raw)
In-Reply-To: <20241113-tcp-md5-diag-prep-v2-0-00a2a7feb1fa@gmail.com>
On Wed, 13 Nov 2024 18:46:39 +0000 Dmitry Safonov via B4 Relay wrote:
> 2. Inet-diag allocates netlink message for sockets in
> inet_diag_dump_one_icsk(), which uses a TCP-diag callback
> .idiag_get_aux_size(), that pre-calculates the needed space for
> TCP-diag related information. But as neither socket lock nor
> rcu_readlock() are held between allocation and the actual TCP
> info filling, the TCP-related space requirement may change before
> reaching tcp_diag_put_md5sig(). I.e., the number of TCP-MD5 keys on
> a socket. Thankfully, TCP-MD5-diag won't overwrite the skb, but will
> return EMSGSIZE, triggering WARN_ON() in inet_diag_dump_one_icsk().
Hi Eric!
This was posted while you were away -- any thoughts or recommendation on
how to address the required nl message size changing? Or other problems
pointed out by Dmitry? My suggestion in the subthread is to re-dump
with a fixed, large buffer on EMSGSIZE, but that's not super clean..
next prev parent reply other threads:[~2024-12-05 1:13 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-11-13 18:46 [PATCH net v2 0/5] Make TCP-MD5-diag slightly less broken Dmitry Safonov via B4 Relay
2024-11-13 18:46 ` [PATCH net v2 1/5] net/diag: Do not race on dumping MD5 keys with adding new MD5 keys Dmitry Safonov via B4 Relay
2024-11-13 18:46 ` [PATCH net v2 2/5] net/diag: Warn only once on EMSGSIZE Dmitry Safonov via B4 Relay
2024-11-13 18:46 ` [PATCH net v2 3/5] net/diag: Pre-allocate optional info only if requested Dmitry Safonov via B4 Relay
2024-11-13 18:46 ` [PATCH net v2 4/5] net/diag: Always pre-allocate tcp_ulp info Dmitry Safonov via B4 Relay
2024-11-13 18:46 ` [PATCH net v2 5/5] net/netlink: Correct the comment on netlink message max cap Dmitry Safonov via B4 Relay
2024-11-16 0:13 ` Jakub Kicinski
2024-11-16 0:08 ` [PATCH net v2 0/5] Make TCP-MD5-diag slightly less broken Jakub Kicinski
2024-11-16 0:48 ` Dmitry Safonov
2024-11-16 1:58 ` Jakub Kicinski
2024-11-16 3:52 ` Dmitry Safonov
2024-11-19 0:12 ` Jakub Kicinski
2024-11-20 0:19 ` Dmitry Safonov
2024-11-20 8:44 ` Johannes Berg
2024-11-20 16:13 ` Dmitry Safonov
2024-11-20 19:36 ` Johannes Berg
2024-11-16 0:20 ` patchwork-bot+netdevbpf
2024-12-05 1:13 ` Jakub Kicinski [this message]
2024-12-05 9:09 ` Eric Dumazet
2024-12-06 0:31 ` Jakub Kicinski
2024-12-06 2:49 ` Dmitry Safonov
2024-12-06 15:14 ` Eric Dumazet
2024-12-06 20:35 ` Dmitry Safonov
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