* [PATCH v2 net] mptcp: fix data stream corruption
@ 2021-05-11 17:13 Paolo Abeni
2021-05-11 22:40 ` Mat Martineau
2021-05-11 23:33 ` patchwork-bot+netdevbpf
0 siblings, 2 replies; 4+ messages in thread
From: Paolo Abeni @ 2021-05-11 17:13 UTC (permalink / raw)
To: netdev
Cc: Mat Martineau, David S. Miller, Jakub Kicinski, mptcp, Maxim Galaganov
Maxim reported several issues when forcing a TCP transparent proxy
to use the MPTCP protocol for the inbound connections. He also
provided a clean reproducer.
The problem boils down to 'mptcp_frag_can_collapse_to()' assuming
that only MPTCP will use the given page_frag.
If others - e.g. the plain TCP protocol - allocate page fragments,
we can end-up re-using already allocated memory for mptcp_data_frag.
Fix the issue ensuring that the to-be-expanded data fragment is
located at the current page frag end.
v1 -> v2:
- added missing fixes tag (Mat)
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/178
Reported-and-tested-by: Maxim Galaganov <max@internet.ru>
Fixes: 18b683bff89d ("mptcp: queue data for mptcp level retransmission")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---
net/mptcp/protocol.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 29a2d690d8d5..2d21a4793d9d 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -879,12 +879,18 @@ static bool mptcp_skb_can_collapse_to(u64 write_seq,
!mpext->frozen;
}
+/* we can append data to the given data frag if:
+ * - there is space available in the backing page_frag
+ * - the data frag tail matches the current page_frag free offset
+ * - the data frag end sequence number matches the current write seq
+ */
static bool mptcp_frag_can_collapse_to(const struct mptcp_sock *msk,
const struct page_frag *pfrag,
const struct mptcp_data_frag *df)
{
return df && pfrag->page == df->page &&
pfrag->size - pfrag->offset > 0 &&
+ pfrag->offset == (df->offset + df->data_len) &&
df->data_seq + df->data_len == msk->write_seq;
}
--
2.26.2
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2 net] mptcp: fix data stream corruption
2021-05-11 17:13 [PATCH v2 net] mptcp: fix data stream corruption Paolo Abeni
@ 2021-05-11 22:40 ` Mat Martineau
2021-05-11 23:33 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 4+ messages in thread
From: Mat Martineau @ 2021-05-11 22:40 UTC (permalink / raw)
To: Paolo Abeni
Cc: netdev, David S. Miller, Jakub Kicinski, mptcp, Maxim Galaganov
On Tue, 11 May 2021, Paolo Abeni wrote:
> Maxim reported several issues when forcing a TCP transparent proxy
> to use the MPTCP protocol for the inbound connections. He also
> provided a clean reproducer.
>
> The problem boils down to 'mptcp_frag_can_collapse_to()' assuming
> that only MPTCP will use the given page_frag.
>
> If others - e.g. the plain TCP protocol - allocate page fragments,
> we can end-up re-using already allocated memory for mptcp_data_frag.
>
> Fix the issue ensuring that the to-be-expanded data fragment is
> located at the current page frag end.
>
> v1 -> v2:
> - added missing fixes tag (Mat)
>
> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/178
> Reported-and-tested-by: Maxim Galaganov <max@internet.ru>
> Fixes: 18b683bff89d ("mptcp: queue data for mptcp level retransmission")
> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
> ---
> net/mptcp/protocol.c | 6 ++++++
> 1 file changed, 6 insertions(+)
Paolo -
Thanks for the tag fix. Patch looks good to me:
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
--
Mat Martineau
Intel
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2 net] mptcp: fix data stream corruption
@ 2021-05-11 22:40 ` Mat Martineau
0 siblings, 0 replies; 4+ messages in thread
From: Mat Martineau @ 2021-05-11 22:40 UTC (permalink / raw)
To: Paolo Abeni
Cc: netdev, David S. Miller, Jakub Kicinski, mptcp, Maxim Galaganov
On Tue, 11 May 2021, Paolo Abeni wrote:
> Maxim reported several issues when forcing a TCP transparent proxy
> to use the MPTCP protocol for the inbound connections. He also
> provided a clean reproducer.
>
> The problem boils down to 'mptcp_frag_can_collapse_to()' assuming
> that only MPTCP will use the given page_frag.
>
> If others - e.g. the plain TCP protocol - allocate page fragments,
> we can end-up re-using already allocated memory for mptcp_data_frag.
>
> Fix the issue ensuring that the to-be-expanded data fragment is
> located at the current page frag end.
>
> v1 -> v2:
> - added missing fixes tag (Mat)
>
> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/178
> Reported-and-tested-by: Maxim Galaganov <max@internet.ru>
> Fixes: 18b683bff89d ("mptcp: queue data for mptcp level retransmission")
> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
> ---
> net/mptcp/protocol.c | 6 ++++++
> 1 file changed, 6 insertions(+)
Paolo -
Thanks for the tag fix. Patch looks good to me:
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
--
Mat Martineau
Intel
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2 net] mptcp: fix data stream corruption
2021-05-11 17:13 [PATCH v2 net] mptcp: fix data stream corruption Paolo Abeni
2021-05-11 22:40 ` Mat Martineau
@ 2021-05-11 23:33 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 4+ messages in thread
From: patchwork-bot+netdevbpf @ 2021-05-11 23:33 UTC (permalink / raw)
To: Paolo Abeni; +Cc: netdev, mathew.j.martineau, davem, kuba, mptcp, max
Hello:
This patch was applied to bpf/bpf.git (refs/heads/master):
On Tue, 11 May 2021 19:13:51 +0200 you wrote:
> Maxim reported several issues when forcing a TCP transparent proxy
> to use the MPTCP protocol for the inbound connections. He also
> provided a clean reproducer.
>
> The problem boils down to 'mptcp_frag_can_collapse_to()' assuming
> that only MPTCP will use the given page_frag.
>
> [...]
Here is the summary with links:
- [v2,net] mptcp: fix data stream corruption
https://git.kernel.org/bpf/bpf/c/29249eac5225
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-05-11 23:33 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-05-11 17:13 [PATCH v2 net] mptcp: fix data stream corruption Paolo Abeni
2021-05-11 22:40 ` Mat Martineau
2021-05-11 22:40 ` Mat Martineau
2021-05-11 23:33 ` patchwork-bot+netdevbpf
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.