commit def5b7b264 upstream.
We have races similar to the one addressed by the previous patch between
subflow failing and additional subflow creation. They are just harder to
trigger.
The solution is similar. Use a separate flag to track the condition
'socket state prevent any additional subflow creation' protected by the
fallback lock.
The socket fallback makes such flag true, and also receiving or sending
an MP_FAIL option.
The field 'allow_infinite_fallback' is now always touched under the
relevant lock, we can drop the ONCE annotation on write.
Fixes: 478d770008 ("mptcp: send out MP_FAIL when data checksum fails")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250714-net-mptcp-fallback-races-v1-2-391aff963322@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ Conflicts in subflow.c, because commit f1f26512a9 ("mptcp: use plain
bool instead of custom binary enum") and commit 46a5d3abed
("mptcp: fix typos in comments") are not in this version. Both are
causing conflicts in the context, and the same modifications can still
be applied. Same in protocol.h with commit b8dc6d6ce9 ("mptcp: fix
rcv buffer auto-tuning"). Conflicts in protocol.c because commit
ee2708aeda ("mptcp: use get_retrans wrapper") is not in this version
and refactor the code in __mptcp_retrans(), but the modification can
still be applied, just not at the same indentation level. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
c476d62758