Re: [PATCH net] l2tp: Serialize access to sk_user_data with sock lock

[Jakub Sitnicki <jakub@cloudflare.com>]

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.

>
>> Reported-by: van fantasy <g1042620637@gmail.com>
>> Tested-by: van fantasy <g1042620637@gmail.com>
>
> Can we get real names? Otherwise let's just drop those tags.
> I know that the legal name requirement is only for S-o-b tags,
> technically, but it feels silly.

I don't make the rules. There is already a precendent in the git log:

commit 5c835bb142d4013c2ab24bff5ae9f6709a39cbcf
Author: Paolo Abeni <pabeni@redhat.com>
Date:   Fri Jul 8 16:36:09 2022 -0700

    mptcp: fix subflow traversal at disconnect time

    At disconnect time the MPTCP protocol traverse the subflows
    list closing each of them. In some circumstances - MPJ subflow,
    passive MPTCP socket, the latter operation can remove the
    subflow from the list, invalidating the current iterator.

    Address the issue using the safe list traversing helper
    variant.

    Reported-by: van fantasy <g1042620637@gmail.com>
    Fixes: b29fcfb54cd7 ("mptcp: full disconnect implementation")
    Tested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
    Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
    Signed-off-by: Paolo Abeni <pabeni@redhat.com>
    Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>