From: Jakub Kicinski <kuba@kernel•org>
To: Kuniyuki Iwashima <kuniyu@amazon•com>
Cc: <andrew+netdev@lunn•ch>, <davem@davemloft•net>,
<edumazet@google•com>, <horms@kernel•org>, <kuni1840@gmail•com>,
<netdev@vger•kernel.org>, <pabeni@redhat•com>
Subject: Re: [PATCH v2 net-next 2/3] pfcp: Convert pfcp_net_exit() to ->exit_rtnl().
Date: Thu, 24 Apr 2025 15:24:10 -0700 [thread overview]
Message-ID: <20250424152410.011b4c9e@kernel.org> (raw)
In-Reply-To: <20250424022531.93945-1-kuniyu@amazon.com>
On Wed, 23 Apr 2025 19:23:28 -0700 Kuniyuki Iwashima wrote:
> > > I guess it was broken recently ? at least I didn't see null-deref
> > > while testing ffc90e9ca61b ("pfcp: Destroy device along with udp
> > > socket's netns dismantle.").
> >
> > Not sure, nothing seems to have changed since?
>
> It's been broken since the first commit of pfcp, but the bug seems
> to be exposed recently by the commit below, which changed the per-cpu
> variable section address from 0 to relative address.
>
> $ git bisect good
> 9d7de2aa8b41407bc96d89a80dc1fd637d389d42 is the first bad commit
> commit 9d7de2aa8b41407bc96d89a80dc1fd637d389d42
> Author: Brian Gerst <brgerst@gmail•com>
> Date: Thu Jan 23 14:07:40 2025 -0500
>
> x86/percpu/64: Use relative percpu offsets
>
> Looks like before this commit 0 was a valid per-cpu variable address
> on x86, and that's why accessing per_cpu_ptr(NULL, cpu) was handled
> (im)properly.
Interesting! I guess in most cases, then, we'd access random data
and just show crazy interface stats prior to that commit?
> The fix is one-liner assigning pcpu_stat_type
Or remove the ndo, and re-add in net-next cause I don't see any actual
stats being counted.
> but no one have used > pfcp for the recent 3 months and haven't
> noticed the wrong stats nor used stats for a year.
>
> Do we want to fix it or remove ? :)
That would be very pleasant indeed :) Let me answer in the other
sub-thread..
next prev parent reply other threads:[~2025-04-24 22:24 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-18 0:32 [PATCH v2 net-next 0/3] net: Followup series for ->exit_rtnl() Kuniyuki Iwashima
2025-04-18 0:32 ` [PATCH v2 net-next 1/3] net: Drop hold_rtnl arg from ops_undo_list() Kuniyuki Iwashima
2025-04-18 0:32 ` [PATCH v2 net-next 2/3] pfcp: Convert pfcp_net_exit() to ->exit_rtnl() Kuniyuki Iwashima
2025-04-23 2:47 ` Jakub Kicinski
2025-04-23 8:37 ` Michal Swiatkowski
2025-04-23 13:33 ` Jakub Kicinski
2025-04-24 4:40 ` Michal Swiatkowski
2025-04-24 22:26 ` Jakub Kicinski
2025-04-25 4:28 ` Michal Swiatkowski
2025-04-23 13:40 ` Jakub Kicinski
2025-04-23 14:12 ` Kuniyuki Iwashima
2025-04-23 22:33 ` Jakub Kicinski
2025-04-23 22:52 ` Jakub Kicinski
2025-04-24 2:23 ` Kuniyuki Iwashima
2025-04-24 22:24 ` Jakub Kicinski [this message]
2025-04-18 0:32 ` [PATCH v2 net-next 3/3] ppp: Split ppp_exit_net() " Kuniyuki Iwashima
2025-04-23 2:50 ` [PATCH v2 net-next 0/3] net: Followup series for ->exit_rtnl() patchwork-bot+netdevbpf
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