[ Upstream commit af295892a7abbf05a3c2ba7abc4d81bb448623d6 ] Function __sctp_write_space() doesn't set poll key, which leads to ep_poll_callback() waking up all waiters, not only these waiting for the socket being writable. Set the key properly using wake_up_interruptible_poll(), which is preferred over the sync variant, as writers are not woken up before at least half of the queue is available. Also, TCP does the same. Signed-off-by: Petr Malat <oss@malat.biz> Acked-by: Xin Long <lucien.xin@gmail.com> Link: https://patch.msgid.link/20250516081727.1361451-1-oss@malat.biz Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Ulrich Hecht <uli@kernel.org>