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From: Tom Parkin <tparkin@katalix.com>
To: Jakub Sitnicki <jakub@cloudflare.com>
Cc: Jakub Kicinski <kuba@kernel.org>,
	netdev@vger.kernel.org, kernel-team@cloudflare.com,
	van fantasy <g1042620637@gmail.com>
Subject: Re: [PATCH net] l2tp: Serialize access to sk_user_data with sock lock
Date: Mon, 15 Aug 2022 09:43:14 +0100	[thread overview]
Message-ID: <20220815084313.GA5059@katalix.com> (raw)
In-Reply-To: <87edxlu6kd.fsf@cloudflare.com>

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On  Fri, Aug 12, 2022 at 11:54:43 +0200, Jakub Sitnicki wrote:
> On Thu, Aug 11, 2022 at 10:23 AM -07, Jakub Kicinski wrote:
> > On Wed, 10 Aug 2022 12:28:48 +0200 Jakub Sitnicki wrote:
> >> Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
> >
> > That tag immediately sets off red flags. Please find the commit where
> > to code originates, not where it was last moved.
> 
> The code move happened in v2.6.35. There's no point in digging further, IMHO.

At the time of fd558d186df2, sk_user_data was checked/set by the newly
added function l2tp_tunnel_create.  The only callpath for
l2tp_tunnel_create was via.  pppol2tp_connect which called
l2tp_tunnel_create with lock_sock held (and indeed still does).

I think the addition of the netlink API (which added a new callpath
for l2tp_tunnel_create via. l2tp_nl_cmd_tunnel_create which was *not*
lock_sock-protected) is perhaps the right commit to point to?

309795f4bec2 ("l2tp: Add netlink control API for L2TP")

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      parent reply	other threads:[~2022-08-15  8:49 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-08-10 10:28 [PATCH net] l2tp: Serialize access to sk_user_data with sock lock Jakub Sitnicki
2022-08-11 17:23 ` Jakub Kicinski
2022-08-12  9:54   ` Jakub Sitnicki
2022-08-12 19:40     ` Jakub Kicinski
2022-08-15  8:43     ` Tom Parkin [this message]

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