Hi Nathan,
On 28/09/2024 19:55, Nathan Chancellor wrote:
Hi all,
On Thu, Aug 15, 2024 at 03:25:13PM +0200, Greg Kroah-Hartman wrote:
5.10-stable review patch. If anyone has any objections, please let me know.
From: Paolo Abeni pabeni@redhat.com
commit 68cc924729ffcfe90d0383177192030a9aeb2ee4 upstream.
When a subflow receives and discards duplicate data, the mptcp stack assumes that the consumed offset inside the current skb is zero.
With multiple subflows receiving data simultaneously such assertion does not held true. As a result the subflow-level copied_seq will be incorrectly increased and later on the same subflow will observe a bad mapping, leading to subflow reset.
Address the issue taking into account the skb consumed offset in mptcp_subflow_discard_data().
(...)
This change in 5.10 appears to introduce an instance of -Wsometimes-uninitialized because 5.10 does not include commit ea4ca586b16f ("mptcp: refine MPTCP-level ack scheduling"), which removed the use of incr in the error path added by this change:
Thank you for having reported this issue!
That change does not really look suitable for stable (unless folks feel otherwise), so maybe a stable only patch to adddress this is in order?
Indeed, better to address this issue in a dedicated patch. This is what I did:
https://lore.kernel.org/20240930162345.3938790-2-matttbe@kernel.org
Cheers, Matt